Ten Things I Like About... Podcast

Coelacanth: Anatomy

Summary: Join Kiersten as she takes you on a surprising journey from the head of the coelacanth to the tail. 
 
For my hearing impaired listeners, a complete transcript of this podcast follows the show notes on Podbean.
 
Show Notes: 
A Fish Caught in Time: The Search for the Coelacanth by Samantha Weinberg
https://www.pbs.org/wgbh/nova/fish/anatomy.html
Music written and performed by Katherine Camp
 
Transcript
(Piano music plays)
Kiersten - This is Ten Things I Like About…a ten minute, ten episode podcast about unknown or misunderstood wildlife.
(Piano music stops)
Welcome to Ten Things I Like About… I’m Kiersten, your host, and this is a podcast about misunderstood or unknown creatures in nature. Some we’ll find right out side our doors and some are continents away but all are fascinating. 
This podcast will focus ten, ten minute episodes on different animals and their amazing characteristics. Please join me on this extraordinary journey, you won’t regret it.
This episode continues the coelacanth and their anatomy is the second thing I like about this ancient animal.
In the first episode we established that the coelacanth is a fish, so the anatomy should be like fish anatomy, right? Maybe, but this fish has been around for 400 million years and from comparisons between living specimens and fossils, they don’t seem to have changed much at all. So the coelacanth has some anatomical surprises that other fish do not possess.
Let’s start at the head of the coelacanth and work our way back. In the center of the snout there is a large jelly-filled cavity. It’s called the rostral organ. Scientists initially thought this might be an electrosensory organ for detecting weak electrical impulses given off by prey. This hypothesis was supported by examining the organ’s intricacies including nerves and how it interacted with the brainstem. When submersible exploration became available to scientists, we were able to test this on a living coelacanth. Using electrical fields, researchers confirmed that coelacanths do indeed respond to electrical fields under water. There is no other vertebrate, that we know of, alive today that has a rostral organ. So we’re already off to an interesting start. Let’s see what else the coelacanth has that other animals may not!
Moving to the mouth we find teeth. That’s not entirely unique in fish that eat other fish and the coelacanth is a carnivore. They have three different shapes of teeth, one is a high, sharp cone-shaped tooth that could be called a fang, the second is a midsized, sharp cone-shaped tooth, and the last is a small rounded tooth.  What is unique to the coelacanth is that the small rounded teeth are embedded in a bony dental plate that lies beneath their chin. We’re not entirely sure what the advantage of having a dental plate gives the coelacanth. In general, the teeth seem more like a way to keep fish in the mouth once they are sucked in versus tearing or chomping on their prey.
The eyes are just above the mouth and they are attached to thick optic nerves. The eyes are large. I’d say they are in proportion to their body and they are a five foot long fish, so…large eyes. Each eye does have a few cones, which allows for color vision, but they many rods, which help detect light. This is perfect for the coelacanth because they live deep under water where there is very little light available. The rods help them see in almost near darkness.  
They also have something else that helps them see in the dark and this is a layer behind the retina of the eye called the tapetum lucidum. If you’ve ever seen light flash in your cat’s eyes at night, you’re seeing the tapetum lucidum. This layer acts like a mirror reflecting the light that comes into the eyes back out of the eye to increase the amount of light that passes over the retina. This enhances the coelacanth’s ability to see in low light.
Just behind the eye toward the top of the head is the intracranial joint. Until we rediscovered the coelacanth this joint had only been seen in fossils of primitive fish. This joint allows the coelacanth to open its mouth exceptionally wide to swallow fish and other prey. Two powerful muscles cross the intracranial joint providing strength to the coelacanth’s jaws. The coelacanth is the only fish alive that still has an intracranial joint. 
Just under this joint and near the eye is the brain. The brain is small. It takes up only 1.5% of the brain case in mature adults. In a 90 lbs coelacanth the brain weighs less than a tenth of an ounce. That’s a pretty tiny brain. There is no extant vertebrate with this much of a difference between the size of the brain and the size of the body. Although, they have been alive for 400 million years so it must be working. 
Coelacanths do have gills like other species of living fish and they are located behind the eye in the usual place that you find fish gills. They are relatively small in comparison to the overall body size, but they are similar to other fish species found at the same depth as the coelacanth. The relatively small surface area of the lungs is indicative of a slow-moving fish as opposed to an active fish. All the evidence we have to date does show that the coelacanth is a relatively slow-moving fish. When you’re a five foot long fish, you take your time getting places.
This large fish is covered in scales and those scales are woven tightly together like armor. I think that seems appropriate for such an ancient animal. The scales are hard and rough to the touch. Each scale has tiny, tooth-like spikes called denticles all over the surface which creates the roughness. The hard scales and denticles provide protection against predators and rocks. The scales are a beautiful steely-blue color with random white spots throughout. The pattern of the spots is unique to each individual and scientists have used that to their advantage. Researchers use the spots like name tags to identify individual coelacanth.
The fins of this fish are quite spectacular. They have six fins that are lobed and this puts them into a group of fish known as the lobed-finned fish. Lungfish and coelacanth are both included in this group.  What’s the difference between a lobed fin and a normal fin? Great question! Lobed fins are fins that are attached to stalks that project out from the body rather than fins that are attached directly to the body. They look kind of like paddles sticking out from the side on the animal. The coelacanth has six lobed fins, one on each side just behind the gills called pectoral fins (2), one on each side of the pelvis called pelvic fins (4), one small secondary dorsal fin on the top of the body (5), and one anal fin on the underside of the body before the tail (6). 
Overall the coelacanth has seven fins, not including the tail. The first dorsal fin is the only non-lobed fin. It’s larger than the other fins and attaches directly to the body. It can be raised and lowered to change its surface area.
We call the coelacanth a vertebrate because it has an internal skeleton which usually implies that it has vertebrae or bones of the spine. Once again the coelacanth surprises us. They have a notochord in place of a bony spine. A notochord is a thick-walled, fibrous, and elastic tube that is filled with oil. This is what the coelacanth has in place of a bony spine. Most creatures with a backbone replace the notochord with vertebrae in the embryonic stage. But adult coelacanth use the notochord for their longitudinal support.
Like almost all other fish species,  the coelacanth has a swim bladder. Fish use the swim bladder to maintain buoyancy in the water. Most fish use air to inflate the swim bladder and they are able to modify the amount of air depending on the depth in which they wish to swim. I bet you didn’t see this coming but…, the coelacanth’s swim bladder is not filled with air! Okay, maybe you did see that coming. The coelacanth’ s swim bladder is filled with oil and fat, but it works the same as the air filled bladder, helping maintain buoyancy. 
That brings us to the end of the fish, also known as, the tail. Hopefully, you’ve listened to the first episode of this series where I talk about the rediscovery of the coelacanth, if not definitely check it out. When Marjorie Courtenay-Latimer rediscovered the coelacanth in 1938, she described the tail as looking like a “puppy dog tail.” The tail is actually divided into three sections with a small tail fin in the middle. The tail is flat and powerful giving the coelacanth the ability to dart forward forcefully when catching prey or escaping predators. The tail can rotate and flex from side to side and is thought to help the fish with trim and balance.
That is all I have for coelacanth anatomy. Thanks for joining me on this head to tail adventure because it’s my second favorite thing about the coelacanth.  
 
If you're enjoying this podcast please recommend me to friends and family and take a moment to give me a rating on whatever platform your listening. It will help me reach more listeners and give the animals I talk about an even better chance at change. 
 
Join me next week for another episode about the coelacanth.  
 
(Piano Music plays) 
This has been an episode of Ten Things I like About with Kiersten and Company. Original music written and performed by Katherine Camp, piano extraordinaire.

Coelacanth: Rediscovered

Summary: In 1938 something amazing happened in a small town off the eastern coast of South Africa. Join Kiersten as she reveals the unbelievable story of how the coelacanth, a fish thought extinct for millions of years, was rediscovered. 
For my hearing impaired listeners, a complete transcript of this podcast follows the show notes on Podbean.
 
Shoe Notes: 
A Fish Caught in Time: The Search for the Coelacanth by Samantha Weinberg
Music written and performed by Katherine Camp
 
Transcript
(Piano music plays)
Kiersten - This is Ten Things I Like About…a ten minute, ten episode podcast about unknown or misunderstood wildlife.
(Piano music stops)
Welcome to Ten Things I Like About… I’m Kiersten, your host, and this is a podcast about misunderstood or unknown creatures in nature. Some we’ll find right out side our doors and some are continents away but all are fascinating. 
This podcast will focus ten, ten minute episodes on different animals and their amazing characteristics. Please join me on this extraordinary journey, you won’t regret it.
This episode begins a new series about an animal thought to have been extinct since the time of the dinosaurs, but as this episode will show the coelacanth has been here all along and this is the first thing I like about them.
We’ll begin with the unbelievable story of the rediscovery of this amazing animal.
Let me set the scene for you: It’s 1938 in the town of East London, South Africa. East London sits on the eastern coast of South Africa and harbors a bustling fishing industry. It’s a hot and humid December day and the young, female curator of the East London Museum is hustling to get her newest exhibition completed before they close for the upcoming Christmas holiday. As Marjorie Courtenay-Latimer is painstakingly assembling a rare dinosaur fossil, a startling sound shatters the peace of the museum and her concentration. It’s the ringing of the newly installed phone and she doesn’t know it yet, but it’s the sound of destiny calling. 
On the other end of the phone is the manager of the Irvin and Johnson trawler fleet. Mr. Jackson would call Marjorie when his ships came back to port with specimens that she might be interested in for the museum. This day Majorie was so stressed to get things organized before the holiday break that she almost said No, but she didn’t want to jeopardize her relationship with the shipping company manager. She decided to take a quick break and see what she could see.
She had no idea what she’d find when she stepped onto the deck of the Nerine. Over the phone Mr. Jackson had indicated that several pounds of sharks were available for her perusal. The museum didn’t need any sharks currently and Marjorie had decided that she’d most likely not take anything, but she took a look through the pile of fish on the forecastle deck anyway. She found sharks, seaweed, starfish, sponges, rat-tail fish, and many more. She carefully sorted through the pile but saw nothing she of interest which strengthened her reserve to take nothing that day. 
About halfway through she noticed a blue fin, not the usual faire, and she dug down through slime and scales to take a closer look. What she’d found was a fish, a very unusual fish.
A quote from the book A Fish Caught in Time: The Search for the Coelacanth by Samantha Weinberg expresses the discovery in Marjorie’s own words.
“I picked away the layers of slime to reveal the most beautiful fish I had ever seen,” she recounts. “It was five feet long, a pale, mauvy blue with faint flecks of whitish spots; it had an iridescent silver-blue-green sheen all over it. It was covered in hard scales, and it had four limb-like fins and a strange little puppy dog tail. It was such a beautiful fish - more like a big china ornament - but I didn’t know what it was.” End quote.
The fisherman who stood by watching, said in thirty years of fishing he’d never seen anything thing like it. They’d caught it at a depth of forty  fathoms, 240 feet, off the mouth of the Chalumna River. When the captain of the ship first saw the catch he’d thought it so beautiful he’d almost set it free. Marjorie’s gut told her to take it. 
She and her museum assistant, Enoch, wrapped the fish in a bag and transported it back to the museum to give it a more complete inspection. It was weighed and measured and Marjorie sketched a rough picture of this puzzling fish. The specimen weighed in at 127 pounds and a voice in Marjorie’s head kept circling back to something she’d learned as a child in grade school. She’d gotten in a bit of trouble with her teacher and had to write a sentence as punishment.
‘A ganoid fish is a fossil fish.’ She had to write it twenty-five times and; therefore, never forgot the statement. Essentially it means a ganoid fish is a fish that has long been extinct and is only seen in the fossil records. (As an aside, Ganoid also refers to a type of scale that can be found in extant fishes such as bowfin, gars, paddlefish, and sturgeon.) This sentence kept running through her head as she examined the fish in front of her, but logically it could not be a ganoid fish because this was a fresh specimen caught just that morning. 
She looked through all the books she had on fish but nothing matched. She decided she must preserve the fish for future examination by someone with a bit more knowledge than herself. Preserving a five foot, 127 pound fish was not something that could be done in the museum, so she had to come up with some alternate plans. First she asked the mortuary if they’d place it in one of their lockers, since the were refrigerated. The mortician balked at storing a giant fish with the bodies of the human dead, he was worried what the town might think. Then she thought of the food storage building. It also hade refrigeration, but that was also a no go. 
Her final option was the taxidermist and he was certainly up for the challenge. Between the two of them they wrapped the humongous fish in formalin soaked towels and stored it in the taxidermist’s store. Next, Marjorie sent a letter to James Leonard Brierley Smith, a chemist lecturer at Rhodes University in Makhanda, South Africa. J.L.B. Smith was an amateur ichthyologist and acted as the honorary curator of fishes for the smaller museums along the south coast, such as the East London Museum. She asked for his help in identifying a strange fish she’d found and sent along her sketch of said fish. 
Because of the holiday, his response was delayed several days. As she waited, Marjorie checked in on her find daily. Despite all their hard work the fish was inevitably deteriorating. The taxidermist had to get to work at his trade to save any portion of the fish. Finally, an answer came back from JLB Smith. It was most likely a coelacanth. Marjorie was gobsmacked. The coelacanth was a fish thought to have gone extinct during the time of the dinosaurs. They hadn’t existed outside of a fossil for 65 million years, or so we thought. Marjorie Courtenay-Latimer’s discovery shook the scientific community.  
I hope this episode whet your appetite to learn more about the coelacanth because their rediscovery is my first favorite thing about these forgotten fish.
If you’d like to know more about Marjorie Courtenay-Latimer and the rediscovery of the coelacanth, I highly recommend the book A Fish Caught in Time: The Search for the Coelacanth by Samantha Weinberg. It is one of my favorite non-fiction reads. 
 
If you're enjoying this podcast please recommend me to friends and family and take a moment to give me a rating on whatever platform your listening. It will help me reach more listeners and give the animals I talk about an even better chance at change. 
 
Join me next week for another episode about the coelacanth.  
 
(Piano Music plays) 
This has been an episode of Ten Things I like About with Kiersten and Company. Original music written and performed by Katherine Camp, piano extraordinaire.

Caecilians: Conservation

Summary: Even though we don’t know much about caecilians they still need our help. Join Kiersten as she talks about what threats caecilians face and how we can help.
 
For my hearing impaired listeners, a complete transcript of this podcast follows the show notes on Podbean.
 
Show Notes: 
IUCN Red List: www.iucnredlist.org
“Fatal fungus found in third major amphibian group, caecilians,” by Natural History Museum, Phys Org; phys.org/news/2013-05-fatal-fungus-major-amphibian-group.html
Chytridiomycosis: Cornell Wildlife Health Lab: cwhl.vet.cornell.edu
Conservation Organizations:
IUCN SSC Amphibian Specialist Group: www.iucn-amphibians.org
Amphibian Ark: www.amphibianark.org
Save the Frogs: savethefrogs.com
Association of Zoos and Aquariums: www.aza.org/amphibian-conservation
 
Music written and performed by Katherine Camp
 
Transcript
(Piano music plays)
Kiersten - This is Ten Things I Like About…a ten minute, ten episode podcast about unknown or misunderstood wildlife.
(Piano music stops)
Welcome to Ten Things I Like About… I’m Kiersten, your host, and this is a podcast about misunderstood or unknown creatures in nature. Some we’ll find right out side our doors and some are continents away but all are fascinating. 
This podcast will focus ten, ten minute episodes on different animals and their amazing characteristics. Please join me on this extraordinary journey, you won’t regret it.
This episode concludes caecilians and the tenth thing I like about these intriguing creatures is the conservation efforts we already have under way to protect their future. 
Throughout the last nine episodes I have clearly established that we don’t know as much about these fascinating amphibians as we should considering how long they’ve been on the planet. Of course, they are fairly secretive living underground and under the water, so it’s definitely been hard to study them. Having said this, you may be wondering how do we know anything about their conservation status if we can’t get an accurate count of how many are in the wild. The answer is, we can’t, but we do have enough information on some of the species to classify them on the IUCN red list of threatened species.
As a reminder, or for the first time if you haven’t listened to any of my previous series’, the IUCN stands for International Union for Conservation of Nature and Natural Resources. They list the conservation status of animals and plants from around the world. A species can be listed as data deficient, which means we don’t have enough information to make a decision on whether the population is so low that the species is in danger of disappearing, or extinct, which means all the individuals of that species have died. They no longer exist. 
There are several stages in-between data deficient and extinct. These classifications help us develop plans to help species survive the changing environment that is most often impacted by human activity.
Of the 200 species of caecilians that we know about, 193 are listed on the IUCN’s red list. 76 are listed as Least Concern which is good, that means their populations are healthy and thriving. 3 are listed as Near Threatened which is a step up from Least Concern, which means they are still okay for now but we should start including them in conservation plans. 7 are listed as Vulnerable which means they are one step away from Endangered and need help now. 16 are listed as endangered which means if efforts are not taken now we could lose this species. And 2 are listed as critically endangered which means they are a step away from extinction. That leaves 89 listed species as Data Deficient, almost half of the known species of caecilians.
Now that we have the numbers, we have to ask what is impacting caecilian populations. I think you, my listeners, may be able to guess. According to the IUCN website habitat loss is the biggest impact on caecilian populations. It’s the subtropical and tropical species that are being disturbed the most and the activities that are impacting them are all human centric activities. Non-timber agriculture is the largest pressure on the habitat in which our most endangered caecilians are found. The pesticides used in association with the agriculture is the next threat to their lives. Since they live in the ground and are dependent on mainly insects for food you can see how they would be majorly impacted by these activities.
So what exactly are we doing to help? The first thing is we’re still studying them. The more information we have about how they live and where they live the better our conservation plans. We have to know what habitat is best for them, what they eat, and how long they live to truly understand how to successfully protect them. Studying their natural history is a great tool for any conservation efforts for their future. Any students or zoologists out there listening that are looking for a species to study, maybe you can think about caecilians.
Studying animal’s in situ, which means out in their natural habitat, can be difficult. First you need to find them, then you need to catch them without harming them, then you measure everything you can possibly measure such as weight, length, color, sex, and any distinguishing characteristics such as scars or patterning. Then before you let them go you tag them with some kind of ID tag that does not harm they, so if they are captured again or seen by naturalists data can be added to their history. For example, when ornithologists catch birds they place a ring around their leg that has a number on it specific to that bird. When that bird is found again or birders report seeing the bird that information is added to their file. This helps us understand how large an animal’s home territory my be, determine migration paths, and can tell us how long they live. 
Caecilians are even more difficult than most because they choose to live underground or underwater making it terribly difficult to find them, and once they have been found we have no way of permanently tagging them. This is something scientists are still working on for further research.
The other thing we are doing is protecting their habitat by declaring swaths of land preserves or national parks. This is often done because other plants and animals in the same area need protection, too. It’s a great side effect for the caecilians.
Habitat loss is not the only thing caecilians need to worry about. Disease is another serious threat to amphibians. One of the worst diseases effecting amphibians is chytridiomycosis. This is an infectious disease caused by a fungus and has been the cause of declines or complete extinction of over 200 amphibian species. It is know to effect over 350 species of amphibians and until 2013 we thought caecilians might be safe. Chytrid fungus gets into the skin of the amphibian which is devastating because amphibians breathe and take up water through their skin. This fungus interferes with that function. An infection is almost always fatal. Because most caecilians are fossorial we had hoped they might be unaffected by chytrid but a study published in 2013 did find the fungus present in 50% of the individuals tested from the wild. This was devastating news.
For years scientists have been working on a cure for the fungus, but very little head way has been made since what kills the fungus often kills the amphibian. Putting anything in on amphibians skin is instantly absorbed into their system, so it’s a thin line between curing and killing. Some head way has been made with an ionic liquid spread on the backs of frogs but this can only be done with captive individuals and is still not 100%. To date we have no real cure for this disease. 
So what can we do to help? If you are a hiker or explorer in areas where amphibians are common, the chytrid fungus is probably found there. To prevent spread of the fungus, disinfect your clothing and gear before you use them again at another site and do not transport amphibians of any kind from one habitat to another.  
On that note, if you are a hobbyist that likes to have amphibians as household pets, including caecilians, be sure you’re not getting your animals from illegal harvesting companies. Trapping for pet trade in another reason our amazing amphibians, including our caecilians, are disappearing. Make sure you’re patronizing a responsible person who sells only animals born in captivity.
For more on what you can do to help caecilians and other amphibians in the wild, check out my show notes where I have a few great organizations listed.
That’s it for caecilians! Thank you for joining me on this journey through caecilian behavior. I know I had an amazing trip and I think you did too. Conservation efforts for caecilians is my tenth favorite thing about this mysterious amphibian. 
 
If you're enjoying this podcast please recommend me to friends and family and take a moment to give me a rating on whatever platform your listening. It will help me reach more listeners and give the animals I talk about an even better chance at change. 
 
Join me in two weeks when we’ll talk about an animal thought extinct since the time of the dinosaurs until it was rediscovered alive and well in 1938! 
 
(Piano Music plays) 
This has been an episode of Ten Things I like About with Kiersten and Company. Original music written and performed by Katherine Camp, piano extraordinaire.

Caecilians: Odds and Ends

Summary: In this episode Kiersten and a guest host talk about a few things we know only a little bit about, such as caecilian origins and how they communicate.
 
For my hearing impaired listeners, a complete transcript of this podcast follows the show notes on Podbean.
 
Show Notes: 
Caecilians: An Overview https://www.sciencedirect.com/topics/agricultural-and-biological-sciences/caecilians
 
“Petrified Forest Brings the Funk with the World’s Oldest Fossil Caecilian.” Park Paleontology News, Vol 15, No 1, Spring 2023. Https://www.nps.gov/aticles/000/petrified-forest-brings-the-funk-with-the-world-s-oldest-fossil-caecilian.htm
Music written and performed by Katherine Camp
Transcript
(Piano music plays)
Kiersten - This is Ten Things I Like About…a ten minute, ten episode podcast about unknown or misunderstood wildlife.
(Piano music stops)
Welcome to Ten Things I Like About… I’m Kiersten, your host, and this is a podcast about misunderstood or unknown creatures in nature. Some we’ll find right out side our doors and some are continents away but all are fascinating. 
This podcast will focus ten, ten minute episodes on different animals and their amazing characteristics. Please join me on this extraordinary journey, you won’t regret it.
This episode continues caecilians and the ninth thing I like about them is a bit of this and a bit of that. In this episode we’re going to talk about some of the amazing things that we only know a little bit about and my husband Georgiy will be joining me.
Hello Georgiy!
Georgiy: Hello!
Kiersten: Are you enjoying my series on caecilians?
Georgiy: Da!
Kiersten: I’m so surprised about all the amazing attributes these animals have. I think it’s my favorite research so far!
Georgiy: I’m surprised that they have lived for so long and we hardly know anything about them!
Kiersten: I agree and speaking of which. New information about their fossil history has recently been discovered!
Georgiy: Really?
Kiersten: Yes! In the Chinle Formation of the Petrified Forest National Park in Arizona, paleontologists have found the oldest caecilian fossils to date.
Georgiy: How old are they?
Kiersten: They are 220 million years old. More than 80 bones from the caecilian named Funcusvermis gilmorei have been found. Scientists are excited about this because it bumps the fossil record of caecilians back about 35 million years. So they are even older than we thought they were. These ancient caecilians have the two rows of teeth like modern day living caecilians but, unlike extant caecilians, they have legs and no tentacles. Finding these fossils answers a question that scientists have had for many years. Where are the Triassic Era caecilians? Now we know!
Georgiy: Does this tell us anything new about modern day caecilians?
Kiersten: Sort of. These fossils help support the hypothesis that living amphibians are more closely related to each other than any of their extinct ancestors. So frogs, salamanders, and caecilians that are alive today are more closely related to each other than their long dead ancestors. Even though modern day amphibians look and act so much different from each other.
Georgiy: That’s interesting.
Kiersten: I think so, too. You know what else is interesting?
Georgiy: What?
Kiersten: Caecilians are both terrestrial and aquatic.
Georgiy: I say again, What?
Kiersten: (laughs) I’ve mentioned this before in a few episodes but I wanted to make it very clear. Some caecilians live on land, terrestrial, and some live underwater, aquatic. The terrestrial species usually live under ground in tunnels, but some live in the thick leaf liter of the tropical forest floor.
Georgiy: Oh…I see. 
Kiersten: Good. Now to throw another curve at you, some species of caecilians live on land as adults but live under water as juveniles.
Georgiy: Whoa! How does that work?
Kiersten: As adults, some caecilian species lay eggs in an underground burrow near fresh water. When the eggs hatch the young make their way to the water where they slither in and spend their larval stage under the water.
Georgiy: How can they breathe?
Kiersten: Oh, good question! While in the egg the young developed external gills to help them breath under water. They also developed lungs so, when they become adults they loose the gills and emerge onto land where they breath air with their lungs. 
Georgiy: That’s just cool! So let me get this straight, some caecilians live their entire lives underground, some spend their entire lives underwater, and some split their lives between the water and the ground.
Kiersten: Exactly! 
Georgiy: This episode has been pretty cool.
Kiersten: But wait, there’s more! Another interesting thing about caecilians is how they communicate. 
Georgiy: Oooo! How do they communicate?
Kiersten: With chemical perception. 
Georgiy: Explain please.
Kiersten: Why certainly. Caecilians are the only amphibians with tentacles. These tentacles are on their face in-between their eyes and nose and detect chemical in the environment. Scientists believe that they also use these to communicate with each other. 
Georgiy: Do they talk to each other a lot?
Kiersten: Most caecilians appear to be solitary, so probably not, but we don’t know much about their social lives. The aquatic caecilian Typhlonectes natans uses chemical cues to find mates. They probably use their tentacles to sense pheromones. It’s highly possible that the terrestrial caecilians do the same thing. 
Georgiy: So they sniff out a good mate.
Kiersten: (laughs) Yes! There is something to be said about a nice cologne.
Well thanks for helping me out today, Georgiy.
Georgiy: You’re welcome.
Kiersten: That all I’ve got for this odds and ends episode. Thanks for joining me for this second to last episode about a little bit of this and a little bit of that about caecilians because it is my ninth favorite thing about them!
 
I would like to take a moment to thank a gentleman at Central Arizona College in Apache Junction, Arizona who went to great lengths to help me find information on the caecilian when I began this series. Thanks Richard, you’re the man!
If you're enjoying this podcast please recommend me to friends and family and take a moment to give me a rating on whatever platform your listening. It will help me reach more listeners and give the animals I talk about an even better chance at change. 
 
Join me next week for the final thing I like about caecilians!
 
(Piano Music plays) 
This has been an episode of Ten Things I like About with Kiersten and Company. Original music written and performed by Katherine Camp, piano extraordinaire.

Caecilians: Defense

Summary: Join Kiersten as she talks about how caecilians defend themselves against predators.
 
For my hearing impaired listeners, a complete transcript of this podcast follows the show notes on Podbean.
 
Show Notes: 
“Morphological Evidence for an Oral Venom System in Caecilian Amphibians,” by Pedro Luis Mailho-Fontana, Marta Maria Antoniazzi, Cesar Alenandre, Daniel Carvalho Pimenta, Juliana Mozer Sciani, Edmund D. Brodie Jr., and Carlos Jared. iScience, Volume 23. Issue 7,101234, July 2020. https://doi.org/10.1016/j.isci.2020.101234
 
“Predation on Caecilians (Caecilia orientalis) by Hawks (Leucopternis princeps) Depends on Rainfall,” by Harold F. Greeney, Rudy A. Gelis, and W. Chris Funk. Herpetological Review, 2008, 39(2), 162-164. 
 
“Skin gland concentrations adapted to different evolutionary pressures in the head and posterior regions of the caecilian Siphonops annulatus,” by Carlos Jared, Pedro Luis Mailho-Fontana, Rafael Marquez-Porto, Juliana Mozer Sciani, Daniel Carvalho Pimenta, Edmund D. Brodie Jr., and Marta Maria Antoniazzi. Scientific Reports 8, Article number: 3576 (2018).
 
“This Worm-Like Amphibian May Pack a Venomous Bite,” by Alex Fox, Smithsonian Magazine, https://www.smithsonianmag.com/smart-news/worm-amphibian-may-pack-venomous-bite-180975266/
Music written and performed by Katherine Camp
 
Transcript
(Piano music plays)
Kiersten - This is Ten Things I Like About…a ten minute, ten episode podcast about unknown or misunderstood wildlife.
(Piano music stops)
Welcome to Ten Things I Like About… I’m Kiersten, your host, and this is a podcast about misunderstood or unknown creatures in nature. Some we’ll find right out side our doors and some are continents away but all are fascinating. 
This podcast will focus ten, ten minute episodes on different animals and their amazing characteristics. Please join me on this extraordinary journey, you won’t regret it.
This episode continues caecilians and the eighth thing I like about these amazing amphibians is how they defend themselves.
Who are caecilians protecting themselves from? We’re aware of a few species of animals that eat caecilians. Snakes, spiders, turtles, and ants have all been reported preying on caecilians. In 2008 a surprising animal was added to this list. A group of researchers watching cameras set up to record a Barred hawk nesting site in Ecuador captured something unexpected. The parents fed their single chick many different animals including 50 individual Caecilia orientalis, a terrestrial caecilian species. Researchers are unsure how a hawk was able to find a subterranean animal easily enough to bring 50 of them to their young, but we can add these hawks to the list of caecilian predators.
So how do caecilians protect themselves from getting eaten? The first way caecilians protect themselves from predators is really a bit of a happy accident and that’s their fossorial lifestyle. Spending most of your life underground does cut down on the number of predators that can find you, although it doesn’t seem to be slowing down the Barred Hawk. Even so, evolution has given terrestrial caecilians a bit of a jump start on protecting themselves by equipping them to live underground. Aquatic caecilians spend a large amount of time close to the substrate of their chosen water source and hidden in dense plant matter, also a great place to start protecting themselves.
Caecilians do have a few other tricks up their sleeves to actively defend themselves from predators. 
But before we get to those, I want to tell you that most of the information I’ve found on this subject comes from the study of one species of caecilian, Siphonops annulatus, so it may not apply to all species of caecilians. One more I caveat need to mention is that this information is based on educated inference. Because we have not actively seen caecilians defending themselves from predators, we are making some assumptions based on the natural history of other species of animals.
Now that’s out of the way, let’s get to the really cool stuff!
Most amphibians are covered in mucus to help with oxygen transmission and disease protection, caecilians are no exception. Actually, caecilians have more mucus glands than any other amphibian. If you remember, in the locomotion episode, I mentioned that some fossorial caecilians, such as Siphonops annulatus, use their mucus to help lubricate their tunnels to make movement easier. To do this they have glands on their heads that create and release the mucus. They also have glands on their rear end and scientists assumed it was for the same reason. Not so. The gland on the rear end expels a poisonous mucus. We assume that this poison is excreted to protect them from predators that might follow them into their tunnels. 
They also tend to plug the opening of their tunnels with their rounded bums when they are sleeping or resting. A perfect way to keep a predator at bay, greet them with a face full of poison!  
Another option Siphonops annulatus has is their bite. A recent study from 2020 has shown that Siphonops annulatus may have a venomous bite! Once again this is a first for an amphibian. It’s not the first time toxins have been found in Order Amphibia. The most famous example is poison arrow dart frogs that produce poison that is excreted onto their skin. Now, they are classified as poisonous because the toxin is transferred through touch. Animals classified as venomous such as rattlesnakes and Gila monsters inject their toxin into another animal through something like fangs or teeth. Up until this recent discovery, we thought there were no venomous amphibians. 
The study found glands closely associated with this caecilian’s teeth. They found the glands in both the upper and lower jaws. These glands are the same type of glands found in certain venomous reptiles. Within the glands researchers found a combination of mucus, lipids, and proteins. The researchers isolated the cells found in the glands and discovered a similarity to oral venom glands identified in the Texas alligator lizard. As of the recording of this podcast the Texas Alligator lizard and Siphonops annulatus are not classified as venomous, but we’ll have to wait to see what future research determines.
Unlike snake venom glands there appear to be no muscles related to the glands in Siphonops annulatus to facilitate injection of poison, but the caecilian teeth are covered in mucus produced by these oral glands. This leads the scientists to believe that the venom may be secreted when the caecilian clamps it jaws down tightly on a prey item.
There needs to be more study to determine whether this substance is a toxin used to immobilize prey and if it is truly a venomous substance at all. Another purpose for this adaptation may also be as a defense against predators. Considering we’ve never seen defensive behavior in Siphonops annulatus in situ, these glands might be related to protection against predators. 
These scientists did find oral glands present in other species of terrestrial caecilians meaning that they all may have venom that they use for capturing prey and for defense. Further research needs to be done to confirm or debunk this. When they looked at some aquatic caecilians they found no oral glands, which truly intrigues researchers. 
That is all we currently know about how caecilians protect themselves from predation, but I’m sure future research will turn up even more amazing information, and I can’t wait to read about those discoveries because defense is my eighth favorite thing about caecilians. 
 
I want to take a moment to say hello to a young listener. Lydia, thanks for listening and I’m so glad you’re enjoying the podcast. Speaking of which…
If you're enjoying this podcast please recommend me to friends and family and take a moment to give me a rating on whatever platform your listening. It will help me reach more listeners and give the animals I talk about an even better chance at change. 
 
Join me next week for another thing I like about caecilians!
 
(Piano Music plays) 
This has been an episode of Ten Things I like About with Kiersten and Company. Original music written and performed by Katherine Camp, piano extraordinaire.

Caecilians: Reproduction

Summary: Now that we know about the existence of caecilians. Let’s talk about how caecilians make more caecilians! Join Kiersten as she walks us through the various ways caecilians reproduce.
 
For my hearing impaired listeners, a complete transcript of this podcast follows the show notes on Podbean.
 
Show Notes:
“The Care and Captive Breeding of the Caecilian Typhlonectes natans” by Richard Parkinson. Herpetological Bulletin, 2004, Number 88.
 
“Reproductive ecology of female caecilian amphibians (genus Ichthyophis): a baseline study” by Alexander Kupfer, Jarujin Nabhitabhata, Werner Himstedt. Boiological Journal of the Linnean Society, Vol 83, Issue 2, October 2004, pg 207-217.
*cool egg pictures in this paper
“Life history and reproduction of the neotropical caecilian Siphonops annulatus with special emphasis on parental care” by Carlos Jared, Pedro Luiz Mailho-Fontana, Simone G. S. Jared, Alexander Kupfer, Jacques Hubert Charles Delabie, Mark Wilkinson, and Marta Maria Antoniazzi. Acta Zoological, Vol 100, Issue 3, pg 292-302.
 
  Music written and performed by Katherine Camp
 
Transcript
(Piano music plays)
Kiersten - This is Ten Things I Like About…a ten minute, ten episode podcast about unknown or misunderstood wildlife.
(Piano music stops)
Welcome to Ten Things I Like About… I’m Kiersten, your host, and this is a podcast about misunderstood or unknown creatures in nature. Some we’ll find right out side our doors and some are continents away but all are fascinating. 
This podcast will focus ten, ten minute episodes on different animals and their amazing characteristics. Please join me on this extraordinary journey, you won’t regret it.
This episode continues caecilians and the seventh thing I like about these hidden gems is how they reproduce.
When it comes to reproduction most animals will reproduce in one of three ways. If you are viviparous, you give live birth to young that have developed in your uterus. If you are ovoviviparous, you give live birth to young that have developed inside eggs that are incubated in your uterus. These young are typically born with a yolk that helps nourish the young for a few days after birth. If you are oviparous, then you lay eggs that are incubated outside the body by parental warm or substrate covering. There are animals out there that reproduce in other ways, but these are the three main ways of animal reproduction.
Caecilians use two of these reproductive techniques. Of the caecilians we know of today, they are either oviparous or viviparous. 
Let’s take a look at our oviparous species’ first. Some research has been done on species in Family Ichthyophiidae. These species lay eggs and their young go through an aquatic larval stage. The species studied in this particular research was found in Thailand and individuals were observed in the wild as well as in captivity.  It was actually one of the first times caecilians in this family had been studied in situ, which means on site in their natural habitat. Ichthyophis kohtaoensis was studied for three consecutive years and researchers discovered many previously unknown behaviors. 
When we talk about reproduction in most species, it tends to revolve around certain times of the year. Very few animals are like humans and reproduce anytime of the year. Most amphibians found in tropical areas jump into breeding mode at the start of monsoon season, so one of the first questions researchers asked is whether this would be the same for caecilians. The answer they found was a bit of yes and a bit of no. Just like other amphibians, caecilians breeding season was cyclical and revolved around the rainy season. But actual mating appeared to begin at the end of the dry season before the rains came and continued into the beginning of the rainy season. Egg laying typically happened after the rainy season had already begun.
When it comes to parental care, if there is any given, it is the female only. Ichthyophis kohtaoensis does incubate eggs for approximately three months. Toward the end of the dry season, females will begin to gain weight in anticipation of remaining in a nest to guard and incubate eggs. The average number of eggs is 37 with a range of 22-58 eggs laid in one nest. Larger females tended to have larger clutch sizes. The eggs are round and clear, so you can see the developmental stages of the young inside. The pictures they included in their  scientific paper were pretty cool!
The nest site is extremely important because the larval stage of this caecilian is spent in the water. Females will chose a site with softer substrate such as sand, loose soil beneath tree roots, and sandy clay loam under grass tufts. Every nest found was between seven to nine feet from the edge of a freshwater source. The sources were varied including standing ponds and pools, slow moving brooks and rivers, and large seasonal ponds. Once the eggs hatch the young make their way into the water and are on their own. Field studies and captive observations indicate a long larval period so the chosen body of water needs to last long enough for the young to survive through this period to adulthood.
This pattern of reproduction is only one option for oviparous species. Another pattern lengthens the parental care window and has been well studied n only one species, Siphonops annulatus. Unlike Ichthyophis kohtaoensis, the young of Siphonops annulatus do not have an aquatic larval stage. When the young of this caecilian hatch they remain in the underground nest with the mother. 
Breeding season occurs about about the same time as our previous caecilian, beginning at the end of the dry season. Females gain weight at this time and lay eggs after the rainy season has begun. This is more support for the hypothesis that caecilian reproduction is cyclical and follows the seasonal changes revolving around monsoon season because this pattern has now been seen in two species from different countries. Ichthyophis kohtaoensis is found in India and Siphonops annulatus is found in Brazil. The observations reported in the study on Siphonops annulatus were collected over a period of ten years and were gathered in situ and in captivity. 
The young of Siphonops annulatus hatch after about a month but remain in the underground nest with the mother for approximately four months. This species practices dermatophagy which means they eat skin. Specifically the young eat the outer layer of their mother’s skin. Part of the weight that the female gains before egg laying includes a thickening of the outer layer of her skin. This layer bulks up with nutritious fatty lipids that the young scrape off using special baby teeth that they lose when they leave the nest. 
In captivity, young have also been seen congregating around the mother’s cloaca, which is the orifice near the end of the tail, consuming a liquid. We don’t currently know what this substance is but it may be another nutritious liquid for the young. After four months of feeding on mom in the nest, the young will emerge into the world and be on their own. Siphonops annulatus lay fewer eggs than Ichthyophis kohtaoensis and this may be due to the intensive parental care Siphonops annulatus provides.
The last form of reproduction in caecilians is live birth and we’re going to look at one of the most well studied species of viviparous caecilians, Typhlonectes natans. Hopefully you remember from previous episodes that this species is an aquatic caecilian, living their entire lives in the water. The information about the breeding behaviors of this species comes mostly from captive specimens, so this information needs to be taken with a little grain of salt because animals always act a little different in captivity than they would in the wild. These behaviors have been in several different individuals; therefore, we feel fairly comfortable saying this is what happens in the wild. 
Once again, it appears that breeding behaviors are influenced by monsoon season, but in a slightly different way than with our egg-laying species. The dry season that comes before monsoon season is when Typhlonectes natans is triggered to begin breeding. Then the females will carry their young through the following rainy season and give birth when the next dry season begins. We have no proven information why this happens, yet, but using some inference, this pattern probably provides females with more consistent access to food while they are pregnant. They carry their young for about 10 months, so it’s important to be healthy and well fed. 
The young are born in the dry season when waters are lower and calmer. This makes it easier for them to get to the surface of the water and that is important because Typhlonectes natans must surface to breath air. The young are in danger of drowning if they can’t breath air from the surface of the water. 
While they are growing inside mom, the young scrap a secretion from the mother’s uterine wall to nourish themselves. They have small fetal teeth that help them collect these nutrients. I can’t believe there is another species of caecilian that eats its mother! 
The developing young also have gills which allows the female to pass oxygen to them in utero. When the young are born, the gills are already gone or disappear within two days. After birth the young will begin to eat small, soft invertebrates within a few days and do not rely on mom for anything. 
Females are not the only one’s involved in the reproductive process. Let’s take a quick moment, because that’s all it’s going to take, to talk about what the male contributes to the next generation of caecilians. Unlike all other amphibians, that we currently know of, caecilian reproduction is internal. Most amphibians lay eggs that are fertilized after they are laid. Caecilian males have a phallodeum which is an organ that they use to pass sperm into the female through her cloaca. No other amphibian does this. With every episode I make, these caecilians become more and more fascinating.
Whether in the water or underground, the males and females twine their bodies together aligning their cloacas up with each other. Then the male inserts his phallodeum into her cloaca and passes her his sperm. A month after mating eggs are either laid or pregnancy indicators, such as weight gain and size growth, are seen.  
All of the behaviors I talked about in this episode are based on observations of just a few species of caecilians and may not apply to other species. There is so much more we have to learn about them and hopefully we’ll be able to do that in the future.
That’s all I wrote about caecilian reproduction and I trust hope you found it as fascinating as I did because it is my seventh favorite thing about the unknown amphibian.
 
If you're enjoying this podcast please recommend me to friends and family and take a moment to give me a rating on whatever platform your listening. It will help me reach more listeners and give the animals I talk about an even better chance at change. 
 
Join me next week for another thing I like about caecilians!
 
(Piano Music plays) 
This has been an episode of Ten Things I like About with Kiersten and Company. Original music written and performed by Katherine Camp, piano extraordinaire.

Caecilians: Diet

Summary: What do these secretive amphibians eat? Join Kiersten as she takes you on a culinary journey in this episode on caecilian diet.
 
For my hearing impaired listeners, a complete transcript of this podcast follows the show notes on Podbean.
 
Show Notes: 
“Caecilian jaw-closing mechanics: integrating two muscle systems” by Thomas Kleinteich, Alexander Haas, and Adam P. Summers. J R Soc Interface, 2008 Dec 6: 5(29): 1491-1504. doi: 10.1098/rsif.2008.0155
 
“Diet of the Banana Caecilian Ichthyophis bannanicus in Mekong Delta, Vietnam” by Binh V. Ngo, Nghiep T. Hoang, and Chung D Ego. Journal of Herpetology, 48(4):506-513 (2014). doi.org/10.1670/13-113.
 
“Rotational feeding in caecilians: putting a spin on the evolution of cranial design” by G. John Easy and Anthony Herrel. Biology Letters (2006) 2, 485-487. doi: 10.1098/rsbl.2006.0516
 
“Dietary Partitioning in Two Co-occurring Caecilian Species (Geotrypetes seraphim and Herepele squalostoma) in Central Africa” by M. T. Kouete and D. C. Blackburn, Integr Org Bill, 2020; 2(1). doi:10.1093/iob/obz035 
 
Music written and performed by Katherine Camp
 
Transcript
(Piano music plays)
Kiersten - This is Ten Things I Like About…a ten minute, ten episode podcast about unknown or misunderstood wildlife.
(Piano music stops)
Welcome to Ten Things I Like About… I’m Kiersten, your host, and this is a podcast about misunderstood or unknown creatures in nature. Some we’ll find right out side our doors and some are continents away but all are fascinating. 
This podcast will focus ten, ten minute episodes on different animals and their amazing characteristics. Please join me on this extraordinary journey, you won’t regret it.
This episode continues caecilians and the sixth thing I like about these awesome amphibians is their diet.
Our understanding of what and how caecilians eat is still evolving but we know enough to know that it is fascinating!
First, let’s talk about what they eat. Caecilians are carnivores. That means they eat meat. There have been enough studies into various species of caecilians that we have a decent idea of what prey items they tend to eat. In general they focus on invertebrates that are commonly found where they live, underground, in the leaf litter of tropical forests, and underwater. Some examples include ants, termites, earthworms, snails, and some caecilians have been recorded eating crabs, lizards, frogs, and blind snakes. Aquatic caecilians eat fish and aquatic invertebrates. You probably get the drift, if it’s an insect or small animal that lives where caecilians live and it fits in their mouth, they’ll eat it.
Since caecilians have no limbs to help them catch or stabilize prey items their jaw muscles and skulls have evolved to produce a high bite force to help prevent prey items from squiggling away. Caecilians have developed a double jaw muscle mechanism that is special to these amphibians. These muscles are different from other vertebrates because they are actually located above and below the jaw as opposed to the side of the jaw. Take a moment here and place your hands on the side of your jaw. Now open and close your mouth. What you feel moving is your jaw muscles. 
If we were able to place our hands on the sides of a caecilian’s jaw, we would not feel those muscles. Scientists think that the placement of the  muscles on the top and bottom of the skull may be due to the close confines of burrows in which the caecilians live and hunt. Whatever the reason it’s one more cool adaptations these amphibians have developed.
In the last episode we talked about the two different skull formations found in caecilians. At first thought, these differences might be due to the burrowing needs of the caecilian, but upon studying bite force and diet the different skull formations may actually be related to bite force. Caecilians who have the perforated, or zygokrotaphic, skull structure utilize the leverage from the two jaw muscles more efficiently than caecilians with the completely roofed, or stegokrotaphic, skull. What exactly does this information indicate? We’re not quite sure yet. We need more research to determine what these results may mean. For now, we’ll just have to settle for the knowledge itself.
Scientists, being the inquisitive people that they are, asked if caecilians might specialize in specific diet items. Two pieces of evidence leans us towards yes as the answer. One piece of evidence supporting this is tooth shape. Caecilains that eat mostly soft-bodied invertebrates, like earthworms, tend to have sharp curved teeth. This allows the teeth to hook into soft tissue and hold tight. Caecilians that tend to eat prey items that have a harder shell, such as snails, have flatter, pedestal style teeth. This allows them to crush and grind the hard shell. 
While we’re talking about teeth, let me toss this cool fact out there. Caecilians have two rows of teeth in their top jaw and may have one to two rows in the bottom jaw! Forgive my side trip, I just couldn’t resist telling you this fascinating fact.
The second form of evidence supporting diet specialization comes from a study done with two species of caecilians that live in the same area but in different layers of soil. Researchers analyzed the diet of Geotrypetes seraphini and Herpele squalostoma two terrestrial caecilians from Central Africa. G. seraphini lives lower in the soil and eats mostly earthworms, while mole crickets which are found higher in the soil or in leaf litter above ground dominated H. squalostoma’s diet. Now, we don’t know if the diet is dependent on where they live or if they live where their preferred diet can be found. That is a study for the future.
Caecilians just can’t stop surprising us! In another study looking at feeding  behavior of caecilians scientists discovered that these amphibians utilize  rotational feeding. What exactly is rotational feeding? Think about those nature programs you’ve seen about African animals being snatched up by a crocodile. The crocodile often catches something larger than it can swallow in one gulp and spins length wise. This behavior is used to reduce the size of a prey item so it can be easily consumed.
In this study, two species of terrestrial caecilians were observed and recorded eating. They caught both species using rotational feeding to successfully maneuver large prey items into their mouths, just like crocodiles. Unexpectedly, the researchers also observed the caecilians using rotational feeding even when they caught smaller prey items that easily fit into their mouths. So the question is why do they spin when the prey item fits easily into their mouth? We don’t have a solid answer to that question yet, but the researchers postulated that because caecilians are blind maybe they are using the rotational feeding to feel the prey item to help them determine what it is. 
The last behavior we’re going to talk about concerning caecilians’ diet is the most fascinating and slightly disturbing food item I’ve come across in all my years as an animal caretaker. Boulengerula taitanus is an African caecilian that begins life by eating its mother’s skin. You heard me correctly, they eat their mother’s skin! What?! 
So, while mom incubates her eggs that she laid in her subterranean tunnel the outer layer of her skin thickens with nutritious fatty lipids. When the young hatch they have special baby teeth that help them shave off the mother’s outer skin layer. This is the only vertebrate known to use this type of parental feeding strategy! I am thankful everyday I wasn’t born bird so my mother didn’t have to puke into my mouth to feed and now I’m thankful I wasn’t born a caecilian so I didn’t have to eat my mother’s skin.
That’s all for this episode and I know you loved this episode on caecilian diets because it’s the most fascinating episode I’ve researched so far and it’s my sixth favorite thing about this amphibian.
If you're enjoying this podcast please recommend me to friends and family and take a moment to give me a rating on whatever platform your listening. It will help me reach more listeners and give the animals I talk about an even better chance at change. 
 
Join me next week for another thing I like about caecilians!
 
(Piano Music plays) 
This has been an episode of Ten Things I like About with Kiersten and Company. Original music written and performed by Katherine Camp, piano extraordinaire.

Caecilians: Locomotion

Summary: Caecilians are legless amphibians, so how do they get around? Join Kiersten as she talks about caecilian locomotion.
 
For my hearing impaired listeners, a complete transcript of this podcast follows the show notes on Podbean.
 
Show Notes:
“The kinematics of locomotion in caecilians: effects of substrate and body shape” by Anthony Here et. al, J Exp Cool A Ecol Genet Physiol. 2010. Https//pubmed.ncbi.nlm.nih.gov
 
“A comparative study of locomotion in the caecilian Dermophis mexicanus and Typhlonectes natans (Amphibia: Gymnophiona)” by Adam P. Summers and James C. O’Reilly, Zoological  Journal of the Linnean Society, Vol 121, Issue 1, Sept 1997, pls 65-76. Https://doi.org/10.1111/j.1096-3642.1997.tb000147.x
 
Music written and performed by Katherine Camp
 
Transcript
(Piano music plays)
Kiersten - This is Ten Things I Like About…a ten minute, ten episode podcast about unknown or misunderstood wildlife.
(Piano music stops)
Welcome to Ten Things I Like About… I’m Kiersten, your host, and this is a podcast about misunderstood or unknown creatures in nature. Some we’ll find right outside our doors and some are continents away but all are fascinating. 
This podcast will focus ten, ten minute episodes on different animals and their amazing characteristics. Please join me on this extraordinary journey, you won’t regret it.
This episode continues caecilians and the fifth thing I like about these supercool amphibians is the way they get around. 
In previous episodes, we have clearly established that caecilians do not have legs, so you may have been asking yourself, how do they get around? Excellent question. Let’s get the answer.
Caecilians are definitely not the only no-legged animal on planet Earth. There are snakes, glass lizards, and fish that do not have legs. Each of these examples have a unique way of locomotion. Caecilian locomotion is something that blows my mind!     
In the last episode we learned that caecilians are divided into ten different families. Most of those families are terrestrial, which means, according to the Oxford Dictionary, of, on, or relating to the earth. Furthermore, many terrestrial caecilians, are fossorial which means they live underground. Nine of our ten families are considered terrestrial caecilians.
So how exactly do caecilians create motion? They use hydrostatic movement. Hydrostatic motion is created when one set of muscles contracts in a circular and longitudinal pattern and another set of muscles stretches in response. Think of how a jellyfish moves. That in and out, almost like breathing, motion is how hydrostatic movement works. Many species of invertebrates use hydrostatic systems to move and several species of vertebrates use hydrostatic systems in specific body parts. 
What makes caecilian hydrostatic locomotion unique is that they are the first known vertebrate to use their entire body as a hydrostatic system for locomotion. How could this get more interesting? I shall tell you! Hydrostatic movement generally depends on utilizing fluid filled portions of the body or vertebrae, but caecilians hydrostatic motion depends on a criss-cross array of tendons that surround their body cavity. Caecilians' skin and skeleton move independently of each other. Muscles do not attach the skin to the skeleton like other vertebrates. This allows them to create twice the maximum forward force of similar sized burrowing snakes that rely on longitudinal movement. 
This is one more example of what makes caecilians so unique in the animal kingdom.
Now that we know exactly how terrestrial caecilians create forward motion let’s look at another characteristic that is influenced by their fossorial lifestyle.
As you know, caecilians don’t have feet, so instead their skull bones have adapted into the perfect shape to move through the soil. They’re skulls are often described as wedge-shaped, compact, and robust. Sounds a lot like a shovel which would be perfect for digging through soil!
Fossorial caecilians’ skull bones have actually fused together in ways that other animals’ skull bones are not fused. There are two types of skull structures in caecilians. The first type is zygokrotaphic in which the skull is perforated between the squamosal, or the side of the skull and the parietal, or the top of the skull. The second type of skull is stegokrotaphic which means the skull in completely roofed. 
These two skull types are incredibly interesting to researchers and have inspired several scientific studies. One study investigated whether the amount of tunneling a species does determines which skull formation is found in their family. The thought was that the completely roofed skull formation would be  better suited to caecilians that burrow in soil more than other species that live mainly in leaf litter. To withstand the force needed to push through the soil a completely fused skull would be better, right? 
What investigators found did not support this hypothesis. There was no evidence showing caecilians with stegokrotaphic skulls had increased burrowing activity. Skull shape may be more influenced by what they eat instead, we’ll talk about this more in next week’s episode.
While investigating this hypothesis the researchers did discover that cranial shape varies greatly throughout caecilians. Even though there is variability in the position of the mouth, the temporal perforation of the skull, and the closure of the eye orbits, caecilian skulls are are generally bullet shaped which helps make burrowing much easier. 
Scientists are always asking questions and a group of researchers studying caecilian movement wanted to know if the length of a caecilian impacted the way they moved. Using x-ray video these scientists recorded the movement of five different species of caecilian that ranged in size. What they discovered was that as the length of the caecilian increased their ability to create the internal concertina motion of hydrostatic movement decreased. As the caecilians increased in length they lost the skin and skeletal independent movement because of the increase in body length. The larger species depended more on lateral movement, even though they are still capable of concertina movement. 
On an interesting note, in all species locomotion choice was dependent on substrate. When they were burrowing through soil they used a whole body or concertina motion to move forward; yet, when they were above the soil they used a lateral movement. This movement is similar to how snakes move in that side to side slithering motion.
Family Typhlonectidae contains our aquatic caecilians. There are 13 species in this family and they all live their entire lives under the water. They also burrow into soil but since the substrate is underwater it’s often more sandy or silty. Many species in this family have lost the concertina movement of terrestrial caecilians. Instead, they rely on a lateral motion to move through the water and soft substrate.
That’s it for caecilian locomotion, I hope you enjoyed this episode because it’s my fifth favorite thing about this awesome animal.
If you're enjoying this podcast please recommend me to friends and family and take a moment to give me a rating on whatever platform your listening. It will help me reach more listeners and give the animals I talk about an even better chance at change. 
 
Join me next week for another thing I like about caecilians!
 
(Piano Music plays) 
This has been an episode of Ten Things I like About with Kiersten and Company. Original music written and performed by Katherine Camp, piano extraordinaire.

Caecilians: Species

Summary: This little known amphibian has 200 different species in its ranks. Join Kiersten as she takes you on a quick tour of the different caecilian species.
 
 For my hearing impaired listeners, a complete transcript of this podcast follows the show notes on Podbean.
 
Show Notes:
The Amphibian Class by Rebecca Stefoff
https://www.britannica.com/animal/caecilian-amphibian/classification
 
Music written and performed by Katherine Camp
 
Transcript
(Piano music plays)
Kiersten - This is Ten Things I Like About…a ten minute, ten episode podcast about unknown or misunderstood wildlife.
(Piano music stops)
Welcome to Ten Things I Like About… I’m Kiersten, your host, and this is a podcast about misunderstood or unknown creatures in nature. Some we’ll find right out side our doors and some are continents away but all are fascinating. 
This podcast will focus ten, ten minute episodes on different animals and their amazing characteristics. Please join me on this extraordinary journey, you won’t regret it.
This episode continues caecilians and the fourth thing I like about this unknown animal is the number of species that we know about.
I have to admit as I was doing my research into the caecilian I was amazed to discover that we actually know of about 200 species of this amphibian. Most of my friends and family looked at me with blank faces when I mentioned that I wanted to do the next series of Ten Things I Like About on caecilians. I had a few people ask me if it was going to be about people from Sicily. (laughs) Clearly not.
This episode will include a lot of scientific names so I apologize in advance but most caecilians don’t have common names since they are not very well known. 
Let’s start off with a little taxonomy, that’s the scientific classification of all living things. All caecilians are in Kingdom Animalia, as are humans, Phylum Chordata, because they are vertebrates with a skeletal system, Class Amphibia, because they are amphibians, Subclass Lissamphibia, and Order Gymnophiona also known as Apoda which is Latin for “without foot”. Within this Order there are ten Families of caecilians.
The different Families of caecilians are distinguished from each other based on physical characteristics and life history. The extant, or living species, are classified by the absence or presence of a tail, the amount of fusion of the skull bones, the degree of movement in the skull, the nature of the annular grooves (these are the cutaneous grooves that circle the body), and the structure of the phallodeum (which is the male’s sex organ). Classification is also based on whether an aquatic larval stage is present in the life history of the caecilian and whether they lay eggs or have live birth.
The youngest family of caecilians is Family Caeciliidae. The species in this family date from the Paleocene era which is 65 to 55 million years ago to today. They have no tails and most have no aquatic larval stage. There are 42 species in Family Caeciliidae. They are native to Central and South America and as adults they range in size from 4 to 60 inches.
The next seven families all date from the Cretaceous period which is 145 to 65 million years ago to today.
Family Dermophiidae includes 13 species. They have secondary annuli with annular scales. They are viviparous which means they give live birth and they are found in Africa and Central and South America.
Family Herpelidae, commonly known as the African caecilians, is native to Africa and includes 9 species of caecilian.
Family Ichthyophiidae species have tails, an aquatic larval stage and are native to Southeast Asia, peninsular India, Sri Lanka, Sumatra, Borneo, and the Philippines. There are 50 species in this family that range in size from 16 to 20 inches as adults. This family is also known as the Asiatic tailed caecilians or the fish caecilians. I couldn’t  determine why they are called fish caecilians but they do have an aquatic larval stage. 
Family Indotyphlidae is native to Africa, the Seychelles, and India. There are 21 speices in this family. Some of them are viviparous and some of them are oviparous which means they lay eggs to reproduce. The viviparous species do not have scales or secondary annuli. The characteristics that bond these species together are their non-perforated ear bone and the presence of teeth in the lower jaw.
Family Rhinatrematidae has tails and aquatic larvae. The 11 species of this family are native to South America and range in size from 10 to 13 inches as adults. This family is also known as the Neotropical tailed caecilians, the American tailed caecilians, or the beaked caecilians. 
Family Siphonopidae, also known as common caecilians, have non-perforated ear bones and no teeth in the lower jaw. The 19 species of this South American caecilian family are oviparous. 
Our last family originating in the Cretaceous period is Family Typhlonectidae. These caecilians have no tails. Adults are aquatic, so these caecilians live their entire lives in the water. The young have gills but the adults breathe through tracheal lungs. There are 13 species in this family and adults range in size from 20 to 28 inches. Family Typhlonectidae is native to South America and are also known as rubber eels. 
Our last two families are our two oldest species and originate in the Jurassic period which is 200 to 145 million years ago. 
Family Scolecomorphidae is native to Africa and only contains 6 species. They have no tail and no aquatic larval stage. Adults range in size from 16 to 18 inches. They are also known as tropical caecilians, the buried-eyed caecilians, or the African caecilians. 
Family Chikilidae is the most recently discovered family but they are one of the two oldest living caecilians. The seven species of this family have two rows of teeth on their lower jaw and are native to northeastern India. The year 2012 brought this terrestrial caecilian into the light and is named after chikila, the northeastern Indian tribal name for this amphibian. 
Now that we’ve talked a bit about the different families of caecilians let’s talk about colors! In the anatomy episode we learned that all capelins essentially look like earthworms, They have no legs, they have annuli that make their skin look segmented, and they are covered in slimy mucus. But we didn’t discuss what colors they come in. Yes! I said colors. 
Many caecilians, actually a lot of caecilians, are a gray to black color, but not all. Some caecilians are blue, some are red or orange, some have accentuated annuli that gives them a two-toned ringed appearance. Some even have bright yellow striping that runs from their head to their tails! Considering all caecilians are blind and live in mostly dark places, we’re not entirely sure why they have different colors, but boy are they pretty. 
Siphonops annulatus is a beautiful azure blue color, the sticky caecilian is dark gray with a yellow stripe down the midline of their body, the Sao Tome caecilian is bright yellow all over, the Panamanian caecilian is lime green! With 200 different species their color possibilities are quite varied.
They vary drastically in size as well. The largest caecilian is Caecilia thompsoni and this species measures in at a whopping 5 feet long! Holy Smokes! They can weigh up to 2.2 lbs. If you’d live to get a chance to see this caecilian plan a visit to Columbia, as this is their native country. 
The smallest caecilian is a tie between Idiocranium russeli from West Africa and Grandisonia brevis, from the Seychelles. These two species grow to only 4 inches. That is quite a difference in size! Boy caecilians sure as fascinating.
Well that’s it for caecilian species, try saying that five times fast, and I know you had a great time with this episode because it’s my fourth favorite thing about caecilians.  
 
If you're enjoying this podcast please recommend me to friends and family and take a moment to give me a rating on whatever platform your listening. It will help me reach more listeners and give the animals I talk about an even better chance at change. 
 
Join me next week for another thing I like about caecilians!
 
(Piano Music plays) 
This has been an episode of Ten Things I like About with Kiersten and Company. Original music written and performed by Katherine Camp, piano extraordinaire.
 

Caecilians: Anatomy

Summary: Caecilians are unique vertebrates that have some incredible anatomy. Join Kiersten as she takes on a tour of the caecilian body.
 
 For my hearing impaired listeners, a complete transcript of this podcast follows the show notes on Podbean.
 
Show Notes:
The Amphibian Class by Rebecca Stefoff
Caecilians: An Overview https://www.sciencedirect.com/topics/agricultural-and-biological-sciences/caecilians
“An insight into the skin glands, dermal scales and secretions of the caecilian amphibian Ichthyophis beddomei.” Damodaran Arun, S. Sandy, Mohammad Abdulkader Akbarsha, Omen V. Omen, and Letha Divya. Saudi J Bill Sci, 2020 Oct:27(10): 2683-2690 doi: 10.1016/j.sjbs.2020.06.009
 
Music written and performed by Katherine Camp
 
Transcript
(Piano music plays)
Kiersten - This is Ten Things I Like About…a ten minute, ten episode podcast about unknown or misunderstood wildlife.
(Piano music stops)
Welcome to Ten Things I Like About… I’m Kiersten, your host, and this is a podcast about misunderstood or unknown creatures in nature. Some we’ll find right out side our doors and some are continents away but all are fascinating. 
This podcast will focus ten, ten minute episodes on different animals and their amazing characteristics. Please join me on this extraordinary journey, you won’t regret it.
This episode continues caecilians and the third thing I like about this wiggly, squiggly amphibian is their anatomy!
We’re going to start on the outside and work our way in by beginning with the skin. Most amphibian skin is slimy because it’s covered by mucus. Caecilians are no exception. They have two types of glands in their skin and one type produces mucus. The mucus covers the entire body so whenever you try to pick up a caecilian it’s slippery and that’s part of the point! Being slippery makes it much harder for predators to get a hold on you.
Another reason for the mucus is to keep the skin moist which helps with temperature regulation and cutaneous respiration. That means you can breath through your skin. 
The second type of skin gland is called a granular gland also known as a poison gland. It does appear that at least some species of caecilians produce a poison in their adult stage. While studying Siphonops annulus, a species of caecilian from Brazil, researchers noticed a concentration of enlarged mucus-producing glands on their head and their bums.
The glands on their head produce mucus to cover their skin as well as lube up their underground burrows to make it easier to move through the tunnels. The glands on their bums release a poisonous mucus that helps in predator defense. 
An extremely unusual and unique characteristic of caecilian skin is that they have scales. Amphibians don’t have scales, but these amphibians do! To make it even weirder their scales are under the top layer of their skin! We don’t know why they have these scales. It may just be an evolutionary hold over from ancestors. But we do know that not all species have scales, which only makes it a bigger mystery. Why do them have them? And what are they used for?
The skin is also segmented with annuli which are grooves that encircle the body. I haven’t found any information on why they have these annuli or what advantage they give the caecilian, but I’m sure there is a purpose for them. 
While we’re still on the outside let’s talk about limbs or legs. Caecilians have none! They are like snakes in this characteristic. Modern day caecilians have no vestigial components of legs at all, no shoulder bones or pelvic girdle indicating that they might have had legs in their evolutionary past. This is a testament to how old these animals are evolutionarily speaking because the fossils we have found from 190 million years ago have legs. We can make an educated guess that the legs became unnecessary as caecilians adapted to live their entire lives underground or underwater. As they evolved the bones that supported these limbs also disappeared.  
In the last episode we discussed senses, so if you’re listening in order you already know that caecilians do not have image processing eyes. Depending on the species the eyes will be covered in skin, bone, or absent all together. Those that still have an eye can probably determine the difference between light and dark but cannot see images. For a more in depth discussion of this, backtrack to episode two.
Since caecilians do not rely on vision to interact with their surroundings, they have developed tentacles that help them smell and feel their environment. The tentacles are located on the face in-between the eye and nostrils. They are short little protrusions that are chemoreceptors. For more on caecilian tentacles check out episode two of this series.
Okay, we’re going to head inside the body through the nares. As we’ve already discovered caecilians can breathe through their skin, but for most of them that does not provide enough oxygen to survive. Most caecilians have a functioning right lung and a vestigial left lung that doesn’t process much at all. The breathing pattern includes a long exhalation with short inhalations through buccopharangeal pumping. Let me explain that sentence. That means they breathe a long breath out and breathe in short breaths by puffing their cheeks and floor of their mouths in and out. This patten of breathing prevents mixing the clean oxygen that comes in and the carbon dioxide that goes out. This seems to unique to caecilians, at least in the amphibian family. The normal respiratory rate of Typhlonectes natans is 4 to 7 breaths per hour!
Most caecilians have at least one lung but two species of caecilians have no lungs at all. They must do all of their respiration through their skin. How coo is that!?
Let’s move on to the skeleton. The most fascinating part of the caecilians skeletal structure is…well, all of it! Since most caecilians dig into soil, whether on land or underwater, their skulls have fused many of the typical individual bones that are found in amphibian skulls so it can withstand the pressure of pushing through the dirt. The head comes to a point at the nose to make it easier to move through substrate. Small, sharp teeth line the inside of the upper and lower jaw. The mouth is on the underside of the head. Three sets of jaw muscles hold the jaw shut tight so no accidental ingestion of soil happens. This is a fascinating adaption to living underground!
Depending on species, caecilians can have 95 to 285 vertebrae that run down the entire body. Double-headed ribs attach to each vertebrae except the one directly behind the skull and the last few toward the tail. The ribs do not support the body structure like some other cylindrical vertebrates. The muscles of the caecilian actually forms a sheath around the skeleton that is attached to the skin with fibrous connective tissue. This allows the skin and muscles to move together. This cylindrical muscle sheath is what gives their body form.
Caecilians lack functional bone marrow which is where blood cells are produced in other vertebrates, so their blood is created by the liver, kidney, spleen, and thymus.  
The digestive tract consists of teeth, tongue, esophagus, stomach, intestines, and a pancreas. Caecilians are carnivores so their digestive tract is set up to digest meat.
Depending the species, the caecilian’s snake-like body ends in a short tail or none at all. The cloaca is located near the tail on the underside of the body. This is an orifice through which waste is dispelled, eggs are laid, and fertilization occurs. Not all at the same time, though.
 
That pretty much covers anatomy for caecilians. I hope you enjoyed learning about their unique physiology because it is my third favorite thing about them.  
 
If you're enjoying this podcast please recommend me to friends and family and take a moment to give me a rating on whatever platform your listening. It will help me reach more listeners and give the animals I talk about an even better chance at change. 
 
Join me next week for another thing I like about caecilians!
 
(Piano Music plays) 
This has been an episode of Ten Things I like About with Kiersten and Company. Original music written and performed by Katherine Camp, piano extraordinaire.