Tag Archives: jellyfish

Episode 392: Moon Jellyfish, Kung Fu Mantis, and Octocorals

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Thanks to Kari and Joel for their suggestions this week! You can find Kari Lavelle’s excellent book Butt or Face? Volume 2: Revenge of the Butts at any bookstore.

Our Kickstarter for some enamel pins goes live in just over a week if you’re interested!

Further reading:

Jellyfish size might influence their nutritional value

History of Taiji Mantis

Glowing octocorals have been around for at least 540 million years

The moon jellyfish [photo by Alexander Vasenin – Own work, CC BY-SA 3.0, https://commons.wikimedia.org/w/index.php?curid=32753304]:

A Chinese mantis [photo by Ashley Bradford, taken from this site]:

Also a Chinese mantis:

A type of octocoral:

Show transcript:

Welcome to Strange Animals Podcast. I’m your host, Kate Shaw.

It’s finally Invertebrate August! We have some great episodes coming up this month, so let’s get started. Thanks to Kari and Joel for their suggestions this week!

First, we’ll start with an invertebrate from Kari Lavelle’s latest book, Butt or Face? Volume 2: Revenge of the Butts! It’s a sequel to the hilarious and really interesting book we talked about last summer. Kari kindly sent me a copy of the book and it’s just as good as the first one. Don’t worry, I won’t spoil the answer of whether the picture in the book is of an animal’s butt or face, but let’s talk about the moon jellyfish.

We’ve talked about jellyfish in several previous episodes, most recently in episode 343. Moon jellyfish is the term for jellies in the genus Aurelia, all of which look so identical that it takes close study by an expert, or a genetic test, to determine which species is which. We’re going to talk about a specific species in this episode, Aurelia aurita, but most of what we’ll learn about it also applies to the other moon jelly species.

Aurelia aurita lives in temperate, shallow water and is often found in harbors and close to shore. It’s mostly transparent and can grow up to 16 inches across, or 40 cm, although most are smaller. It’s sometimes called the saucer jelly because when its bell is open, it’s shaped sort of like a saucer or shallow bowl, if the bowl was upside down in the water with pinkish-white internal organs inside and short stinging tentacles. That’s most bowls, I think.

Unlike a lot of jellyfish, the moon jelly doesn’t have long tentacles that hang down from the middle of the bell. Instead, its tentacles are short and thin and line the edges of the bell. There are hundreds of them, but while the tentacles do have stinging cells, they’re not very strong. If you were to pet a moon jelly, you probably wouldn’t even feel the stings but you’d probably get sticky digestive mucus on your hands from the tentacles. The mucus is sticky to trap tiny pieces of food, which can include everything from fish eggs and various types of larvae to microscopic animals called diatoms and rotifers.

The moon jellyfish can survive in water with low oxygen, and in fact it prefers low oxygen water. Since most larger marine animals that live near the surface need a lot of oxygen to survive, the moon jelly can safely find its tiny food in low-oxygen areas without worrying too much about predators. Actually the moon jellyfish doesn’t worry about much of anything, because like other jellies, technically it doesn’t have a brain, just a nerve net.

Speaking of predators, for a long time scientists have wondered why anything bothers to eat jellies. They’re mostly water, which makes them easy for other animals to digest, but they contain almost no nutritional value. A study published in March 2023 determined that the bigger the jellyfish is, the more fatty acids its body contains, and fatty acids are an important nutrient. The main difference between a little jelly and a big jelly (besides size) is what they eat, so scientists think the bigger jellies are eating prey that contain more fatty acids, which slowly accumulate in the jelly’s body too.

Next, Joel sent a bunch of excellent suggestions for invertebrates, so many good ones I had trouble choosing which one to put in this episode. I chose the kung fu mantis because I love the Kung Fu Panda movies and think Mantis is an awesome character who is not appreciated enough.

Everyone loves praying mantises and we’ve talked about various species in different episodes, most recently episode 375. The one we’re talking about today is specifically called the Chinese mantis, Tenodera sinensis, which is native to Asia but which is invasive in parts of North America. It grows over 4 inches long, or about 11 cm, and is brown and green in color. It has a yellow spot between its raptorial arms, which as you can guess from the “raptor” part of that word are the arms with the big spikes that help it catch and kill its prey.

The reason this mantis is also called the kung fu mantis is because its ferocity and grace when hunting inspired a style of martial arts in China hundreds of years ago. The story goes that a great hero called Wang Lang was defeated in a duel, and afterwards set himself to study and train harder. One day he noticed a bird trying to catch a praying mantis, but the mantis was so skilled in defending itself against a much larger opponent that the bird eventually gave up and flew away. Wang Lang was inspired to incorporate the mantis’s movements into kung fu, and afterwards he never lost a duel.

Like other mantises, the Chinese mantis will eat pretty much anything it can catch. That’s mostly insects and spiders, but occasionally it will eat frogs and other amphibians, lizards and other reptiles, and occasionally even small birds. It’s a good insect to have around the garden because it eats so many garden pests, but it also eats bees and butterflies, which isn’t so good for the gardener. The Chinese mantis also eats other mantises, which is a problem in North America where it will kill and eat the native mantis species. But because the Chinese mantis is easy to keep in captivity, if you order mantises to release in your garden in the United States, as a natural pest control, there’s a good chance that the species is actually the Chinese mantis. The native Carolina mantis looks very similar but is smaller, only about 2.5 inches long, or 6 cm.

The Chinese mantis also eats other Chinese mantises. You may have heard about how the praying mantis female will bite the male’s head right off after or even while they’re in the process of mating, and then she’ll just eat him up for a nice big meal to help her develop her eggs. This is actually something that happens, although not always. In the case of the Chinese mantis, scientific observations have found that the female eats the male about half the time.

Let’s finish with a type of coral you may not have heard of, octocoral, also called soft coral. We’ve mentioned corals lots of times in various episodes but we haven’t really discussed them in detail. When most people think of coral they think of stony corals that make up coral reefs. Most corals are colonial animals, meaning each individual polyp grows together in a group, and stony coral polyps form a type of exoskeleton or shell made of calcium carbonate to protect its soft body. The polyps have small tentacles that they extend into the water to catch plankton and other particles of food, although some species are larger and can even grab little fish. The tentacles contain stinging cells called nematocysts that can stun or even kill small animals. As the colony grows, with old polyps dying and young polyps attaching to the hard skeletons left behind, the reef gets larger and larger as the years pass.

Not all stony corals live in shallow warm water and build reefs. Some live in cold water and deeper water, and there are even deep-sea corals, and these types of coral don’t build reefs. Octocorals don’t build reefs and are found in both shallow and deep water, and they don’t form hard skeletons.

Instead, the polyps of octocoral form a soft tissue full of tiny channels that allow water through. Octocorals are colonial, so the tissue of each polyp blurps together with those of all the other polyps around it. Some species of octocoral secrete little pieces of harder material to help the tissue keep its shape, but most species are still overall quite soft. It’s strong, though, and the tiny channels through it allow water to carry nutrients to all the polyps.

The octocoral gets its name because it has exactly eight tentacles, although the tentacles are feathery in appearance with lots of little branches growing off the main tentacle. This allows it to catch more tiny food. Some octocorals have long, elaborate tentacles, which has earned them the names sea fans and sea pens, from the old-timey days when pens were made from big feathers.

Corals in general appear in the fossil record for about half a billion years, with stony corals more likely to preserve for obvious reasons. Many species of octocoral exhibit bioluminescence, and that leads us to a recent study, published in April 2024.

Until this new study, scientists estimated that the first bioluminescent creatures lived around 250 million years ago. Bioluminescence has evolved separately over 100 times, though, and is found today in animals as different as fungus and fish. For the new study, scientists analyzed the genetics of 185 octocoral species to see how they were related, and then compared their findings with fossil corals to learn more about when the species split from their common ancestors. That gave them a good idea of when octocorals might have evolved originally and hinted at which ancestors were bioluminescent. They estimated that the first octocoral evolved around 540 million years ago and was already bioluminescent!

The scientists who worked on the study suggest that bioluminescence may have developed originally as a byproduct of other chemical reactions, but it was useful to the animal by possibly attracting food or other octocorals. Bioluminescence is common in marine animals these days, especially in deep-sea animals, so it’s possible that the ocean half a billion years ago was filled with lights from octocorals and many other organisms.

You can find Strange Animals Podcast at strangeanimalspodcast.blubrry.net. That’s blueberry without any E’s. If you have questions, comments, or suggestions for future episodes, email us at strangeanimalspodcast@gmail.com. We also have a Patreon at patreon.com/strangeanimalspodcast if you’d like to support us for as little as one dollar a month and get monthly bonus episodes.

Thanks for listening!

Episode 343: Mystery Jellyfish

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This week we finish out Invertebrate August with some mysterious jellyfish, including a suggestion by Siya!

Further reading:

Mystery giant jellyfish washes up in Australia

New jellyfish named after curious Australian schoolboy

Mysterious jellyfish found off the coast of Papua New Guinea intrigues researchers

Newly discovered jellyfish is a 24-eyed weirdo related to the world’s most venomous marine creature

Rare jellyfish with three tentacles spotted in Pacific Ocean

The Immortal Jellyfish

A mystery jellyfish washed up on an Australian beach [photo by Josie Lim]:

The tiny box jellyfish found in a pond in Hong Kong:

The very rare Chirodectes:

The mystery jelly that may be Chirodectes or a close relation:

A mystery deep-sea jelly with only three tentacles:

Bathykorus, a possible relation of the three-tentacled mystery jelly:

Show transcript:

Welcome to Strange Animals Podcast. I’m your host, Kate Shaw.

It’s hard to believe Invertebrate August is already ending, so let’s finish the month out with some mystery jellyfish, including a recent suggestion from Siya!

When you visit the beach, it’s pretty common to find jellyfish washed ashore. They’re usually pretty small and obviously you don’t want to touch them, because many jellies can sting and the stings can activate even if the jelly is dead. Well, in February 2014, a family visiting the beach in Tasmania found a jelly washed ashore that was a little bit larger than normal. Okay, a lot larger than normal.

The jellyfish they found measured almost five feet across, or 1.5 meters. It had flattened out under its own weight but it was still impressive. The family was so surprised at how big it was that they sent pictures to the state’s wildlife organization, who sent scientists to look at it. The scientists had heard reports of a big pink and white jellyfish for years, and now they had one to examine. Dr. Lisa-ann Gershwin thought it might even be a new species of lion’s mane jelly.

New species of jellyfish are discovered all the time. Dr. Gershwin has described over 200 new species herself. One example is a jellyfish discovered by a nine-year-old.

In 2013, a nine-year-old boy in Queensland, Australia was fishing in a canal with his dad and a friend, when he noticed a jellyfish and scooped it up with a net. Its bell was only about an inch long, or 2.5 cm, and the boy thought it was really cute and interesting. He wanted to know what kind of jellyfish it was, so after some pestering on his part, his dad helped him send it to the Queensland Museum for identification.

Dr. Gershwin was the jellyfish expert at the museum at the time, and she was as surprised as the boy’s dad to discover that the jellyfish was new to science! The boy’s name was Saxon Thomas, and to thank him for being so persistent about getting his jellyfish looked at by a scientist, the jellyfish was named Chiropsella saxoni. It’s a type of box jellyfish, which can be deadly, but this one is so small that it’s probably not that dangerous to humans. You still wouldn’t want to be stung by one, though, I bet.

In 2022, a diver visiting Papua New Guinea got video of several really pretty jellyfish. He sent the video to Dr. Gershwin, who realized the jelly was either a very rare jelly called Chirodectes, or it was new to science.

Chirodectes was only discovered in 1997 and described in 2005. It’s a type of box jellyfish and only one specimen has ever been collected, caught off the coast of Queensland, Australia near the Great Barrier Reef after a cyclone. Its bell was about 6 inches long, or 15 cm, but if you include the tentacles it was almost 4 feet long, or 1.2 meters. It’s pale in color with darker rings and speckles on its bell.

The 2022 video appears to show a jellyfish without speckles or other markings, and it’s also larger than the single known Chirodectes specimen. Its bell appears to be about the size of a soccer ball, or a football if you live in most of the world. However, Dr. Gershwin and other experts who have studied the video say that it’s similar in many ways to Chirodectes and may be a close relation. Since all we have is the video, there’s no way to tell for sure if it’s a species new to science.

Most box jellies live around Australia and New Guinea, but in 2020 scientists in Hong Kong studying organisms living in an intertidal shrimp pond noticed a jellyfish they didn’t recognize. It was tiny, even smaller than Saxon’s little box jelly, with a bell barely half an inch long, or about 15 mm. There were hundreds of the little jellies in the pond, which connects to the ocean with a narrow tidal channel, and they appeared to be eating the tiny shrimp living in the pond. Close study of the jelly determined that it was indeed a new species.

The box jelly gets its name from its bell shape, which is shaped sort of like a cube. Most species are transparent to some degree, with tentacles that hang down from the corners of its cube-shaped bell. Most box jellies are fast swimmers, able to use jet propulsion to move around. Some species, including the newly discovered Tripedalia maipoensis from Hong Kong, even have paddle-like structures at the end of their tentacles to help them swim. Tripedalia probably isn’t dangerous to humans, but the scientists who studied it don’t know for sure because no one wanted to volunteer to be stung by it.

In 2015, the Ocean Exploration Trust was conducting an expedition in the Pacific Ocean, pretty much as far away from land as it’s possible to get, when they saw a mysterious little jellyfish. It was brown in color, but it only had three tentacles—and those tentacles emerge from the top of its bell, not from underneath. Then, in June 2023, another Ocean Exploration Trust expedition spotted the same type of jelly. It’s only the second time it’s been seen, and we know almost nothing about it.

The mystery jelly swims with its tentacles pointing forward, and scientists think that it hunts other jellies and small animals. When its tentacles touch an animal, it grabs it. But that’s pretty much all we know about it so far. Researchers think it might be related to the deep-sea hydrozoan Bathykorus, which was only described in 2010.

Bathykorus is sometimes called the Darth Vader jellyfish, because the shape of its bell kind of resembles Darth Vader’s helmet. Unlike Darth Vader, though, Bathykorus is mostly transparent and has eight tentacles. Four grow from the top of its bell, four grow from the bottom, and it holds the top tentacles up while it swims. It’s been found as deep as 8,200 feet below the surface of the Arctic Ocean, or 2,500 meters. And that’s pretty much all we know about this jelly, even though scientists have been able to carefully capture a few specimens and keep them alive for a few days in specially constructed tanks that mimic conditions found in the deep sea.

Let’s finish with a suggestion from Siya, the immortal jellyfish. It’s tiny, barely more than 4 mm across as an adult, and lives throughout much of the world’s oceans, especially where it’s warm. It eats tiny food, including plankton and fish eggs, which it grabs with its tiny tentacles. Small as it is, the immortal jellyfish has stinging cells in its tentacles. It’s mostly transparent, although its stomach is red and an adult jelly has up to 90 white tentacles.

The immortal jellyfish starts life as a larva called a planula, which can swim, but when it finds a place it likes, it sticks itself to a rock or shell, or just the sea floor. There it develops into a polyp colony, and this colony buds new polyps that are clones of the original. These polyps swim away and grow into jellyfish, which spawn and develop eggs, and those eggs hatch into new planulae.

Polyps can live for years, while adult jellies, called medusae, usually only live a few months. But if an adult immortal jellyfish is injured, starving, sick, or otherwise under stress, it can transform back into a polyp. It forms a new polyp colony and buds clones of itself that then grow into adult jellies.

This is all really interesting, and scientists are studying the immortal jellyfish to learn more about how it manages this incredible feat. It’s the only organism known that can revert to an earlier stage of life after reaching sexual maturity. But only an individual at the adult stage, called the medusa stage, can revert to an earlier stage of development, and an individual can only achieve the medusa stage once after it buds from the polyp colony. If it reverts to the polyp stage, it will remain a polyp until it eventually dies. However, it will bud off clones of itself that develop into medusae.

In other words, an immortal jellyfish isn’t technically immortal, but it can certainly prolong its life in an extraordinary way. It’s also really cute.

You can find Strange Animals Podcast at strangeanimalspodcast.blubrry.net. That’s blueberry without any E’s. If you have questions, comments, or suggestions for future episodes, email us at strangeanimalspodcast@gmail.com. We also have a Patreon at patreon.com/strangeanimalspodcast if you’d like to support us for as little as one dollar a month and get monthly bonus episodes.

Thanks for listening!

Episode 248: The Giant Jellyfish Revisited

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Sign up for our mailing list! We also have t-shirts and mugs with our logo!

We’re down to the last few days to back our Kickstarter!

We’ve got a slightly different type of episode this week. Follow along as I try to find out more about the giant jellyfish that nearly sank a ship!

Further reading:

Kraken: Monster of the Deep

A lion’s mane jellyfish:

A giant squid:

The first photo ever taken of a giant squid:

Show transcript:

Welcome to Strange Animals Podcast. I’m your host, Kate Shaw.

Halloween is behind us and we’re all now ready to head into winter, if we live in the northern hemisphere, or summer, if we live in the southern hemisphere. This week’s episode is a little different, but hopefully you’ll like it.

Before we get into this week’s topic, let me give you the very last Kickstarter update, I promise! From here on out you’ll only get updates through the Kickstarter page if you backed the project. If you’re listening to this episode within a day or two of its release on November 1, 2021, you still have time to back the Beyond Bigfoot & Nessie book! The campaign ends on Nov. 5, but at 12:03 am eastern time, and one of the many things I’ve learned about running a Kickstarter is maybe don’t launch the project at midnight because then it ends at midnight. Remember that if we reach 100 backers before the end, I’ll release a second bonus episode from the audiobook. I’m really late getting this episode done so it’s actually Halloween as I record this, and we currently have 67 backers, which is amazing! Remember, we have a $1 tier if you just want to pitch a dollar in.

That reminds me, after the campaign is over I’m going to update the first bonus episode and take out the ten minutes of Kickstarter talk that starts it. Thanks again to everyone who’s backed the project. I’m blown away by everyone’s support! If you want a copy of the book but not right now, it’ll be available to buy from your regular book-buying places but only after all the Kickstarter backer rewards are sent.

As it happens, this week’s episode is connected with the Beyond Bigfoot & Nessie book. Specifically, I decided to add a chapter about the giant jellyfish we talked about in episode 16, but to do that I needed to do a lot more research.

That story has actually bothered me for a long time. When I first started the podcast, I wasn’t always as diligent in my research as I am now. If a story came from a source I trusted or had enough realistic-sounding details, I’d assume it was accurate. This story met both criteria but whenever I thought about it, something felt off. So I was glad to dig in and find out more.

This episode is about the research process I went through, which will give you a little bit of a behind-the-scenes look at how I approach each episode. We’ll also learn about a couple of other weird events where a ship or boat was seemingly attacked by a sea monster.

Let’s start with the story as I reported it in episode 16. I think you will appreciate how much better our audio quality is these days. Here it is:

“In 1973, the Australian ship Kuranda collided with a huge jelly in the South Pacific while traveling through a storm on her way to the Fiji Islands. The jelly was so enormous that the deck was covered in jellyfish goo and tentacles up to two feet deep [61 cm]. One crew member died after getting stung. The weight of the jelly was so great, an estimated 20 tons [18 metric tons] that it started to push the ship nose-down and the captain, Langley Smith, sent out an SOS. The salvage tug Hercules arrived and sprayed the Kuranda’s deck with a high-pressure hose, dislodging the jelly. Samples were sent to Sydney and tentatively identified as a lion’s mane jelly.”

My first step was to find where I got that story. I was pretty sure it was from Karl Shuker’s blog but when I looked, it wasn’t there. I checked his books that I own and it wasn’t there either. A quick internet search turned up the story in a lot of places with more or less identical wording, but no one said where they’d found the story—except one site, which referenced a book called Mysteries and Monsters of the Sea.

I looked it up and discovered it was a 1998 book, also published as Mysteries of the Deep, made up of articles from FATE Magazine. One of those articles is titled “Giant Jellyfish” and is by Karl Shuker.

The story appeared in the March 1994 issue of FATE, so my next step was to find the article. Karl Shuker is a zoologist who writes a lot about mystery animals, and he’s very good about sharing his sources.

FATE Magazine is still around and isn’t giving its old issues away for free. Then, in one of those amazing, wonderful coincidences, I found an ebay auction for that very issue that had nice clear photographs of several pages to show how good a condition it was in. One of those pages just happened to be the one I needed. I grabbed a screenshot and enlarged it so I could read the text. Shuker writes, “One of the most dramatic cases on record was documented by James Sweeney in Sea Monsters (1977), and took place in January 1973.”

Bingo! Now I just had to find a copy of that book. I found a used copy online that wasn’t very expensive and ordered it, but a little more searching online led me to a digitized version that I was able to access by logging in to the Internet Archive.

I found the story on pages 73-76. It has lots of details that should be easily corroborated, although unfortunately there isn’t a specific date. My next step was my newspapers.com account to see how the event was reported at the time.

This is where I came up against a blank wall. There was nothing in any of the hundreds of digitized newspaper archives available. I searched for the name of the ship, the Kuranda. I searched for the name of the captain, Langley Smith. I couldn’t find a single mention of either, never mind an encounter with a gigantic jellyfish.

It wasn’t looking good for the story, but I had one more clue. The account starts out in Sweeney’s book:

“One of the strangest, and probably best documented, sea monster stories to be found anywhere is recorded in the Colonial Secretary’s File of the Archives, State Library, Melbourne, Australia. Written testimony submitted by the officer of the watch and others tells clearly what happened to the steamer Kuranda.”

Melbourne is in Victoria, so after some searching online for the archives mentioned in the book and not finding them, I used the Ask a Librarian feature on the State Library Victoria website. I got a response only a few hours later asking for a little more information, which I supplied. I gave the gist of the story, including the details of the ship’s name, the captain’s name, and so forth, and I even gave the link to the digitized version of Sweeney’s book.

A few days later I got a response from a librarian named Jane. I’ll break it down for you.

Jane discovered there were two ships named Kuranda. One was broken up in 1936, the other wrecked in 1969.

In 1973, when this story was supposed to have taken place, there was no longer a colonial secretary in any Australian state. Therefore there is no Colonial Secretary’s File of the Archives from 1973 or after.

And there are no records of a Langley Smith who is a ship’s captain.

At this point I decided, reluctantly, that the story is probably fiction. I actually dug around looking at the table of contents of various 1970s magazines that might have published a fictional story about the giant jellyfish and claimed or implied it was real. I even thought about finding Sweeney’s email and just asking him if he remembered where he learned about this story. Sadly, it turns out that he died in 2019.

According to his obituary, Sweeney worked as a forest ranger for most of his life and was also a voracious reader. I don’t want to believe that a forest ranger who likes to read could possibly stretch the truth so I assume he read about the giant jellyfish somewhere, thought it was a true story, and added it to his book. This was long before the internet so he couldn’t just look stuff up online like I’m doing.

Just to make sure, though, let’s take a look at something else Sweeney mentions in his book. He writes, “Perhaps those aboard Kuranda were luckier than they realized. For the Times of London carried a story somewhat similar. Unfortunately, it ended in absolute horror.”

Back I went to newspapers.com, and by the way, a big thanks to the podcast’s Patreon supporters whose contributions allow me to subscribe. The Times isn’t listed on the site, which mostly focuses on American newspapers, but when I did a search for the name of the ship given in Sweeney’s book, the steamer Strathowen, during the 1870s when he reported it occurred, I got lots of hits.

Here’s an excerpt from The Freeman’s Journal of Dublin, Ireland from July 2, 1874.

“The octopus is likely to lose none of its popularity in the Brighton Aquarium, if we are to believe a strange story which comes from India. The master of the screw steamer Strathowen, on his way to Madras, observed a little schooner lying becalmed, and between him and her what he at first thought to be a bank of weed. The mass was perfectly quiet, but after a time began to move towards the schooner. Suddenly it struck her, and sunk her to the bottom. The master of the Strathowen put about, dropped boats, and saved five men from the sunken ship. James Floyd, the master, was rescued, and he tells his story in the most circumstantial fashion. The Pearl schooner, 150 tons, was bound from the Mauritius to Rangoon. On the 10th of May about five in the evening he observed a great mass rising slowly out of the sea. It remained stationary, and looked like the back of a huge whale. In a hapless moment he took his rifle and hit the monster, which began to lash about furiously. … All the men were then ordered up, and knives and hatchets and cutlasses were grasped, and all awaited the advent of the terrible stranger. The narrator proceeds: ‘We could now see a huge oblong mass moving by jerks just under the surface of the water, and an enormous train following; the oblong body was at least half the size of our vessel in length, and just as thick. The wake or train might have been 100 feet long. In the time that I have taken to write this, the brute struck us, and the ship quivered under the thud; in another moment, monstrous arms like trees seized the vessel, and she heeled over. In another second the monster was aboard, squeezed in between the two masts…. [T]he brute holding on by his arms, slipped his vast body overboard, and pulled the vessel down with him on her beam ends.” The general opinion amongst the sailors is that the big bank of sea-weed was an octopus, but we dare say a little confirmation of the story would be welcomed by us all whether naturalists or not.”

This is actually a brief and measured account of the story that appeared in the Times and which later hit the American papers. The longer account reads very much like fiction. The Dublin paper’s tone of interested skepticism matches what I feel, but the story does corroborate what Sweeney wrote in his book about sea monsters, so at least Sweeney wasn’t making stuff up.

I found a 2019 article in Skeptical Inquirer that did all the research about the octopus or squid sinking the Pearl. According to the author, there’s no record of a ship named the Strathowen or a captain named James Floyd. The author also points out that Jules Verne’s novel Twenty Thousand Leagues under the Sea was published in 1869, only five years before, and included an attack on the submarine by giant cephalopods.

Before you get too discouraged, though, the Skeptical Inquirer article also talks about a giant squid attacking a small boat, and that one actually happened.

In October 1873 in Conception Bay, Newfoundland, two fishermen and a boy were crossing the bay in a rowboat and noticed something floating in the water. As they neared it, it grabbed the boat with two tentacles and pulled so hard that the boat started to take on water. Luckily there was a hatchet in the boat, and the boy grabbed it and chopped off the tentacles. Later he sold the longer tentacle to a minister who lived nearby and who was interested in squid, which were often referred to as devil-fish back then. The minister, Moses Harvey, wrote about it later and reported that the partial tentacle was as thick as a man’s wrist and measured 19 feet long, or almost 6 meters.

Only a few weeks later Harvey bought a giant squid that had been tangled in a fishing net and hauled ashore. He arranged to get a photograph of it because he knew a lot of people wouldn’t believe how big it was otherwise, and his photo was the very first one taken of a giant squid. It wasn’t until 2004 that the first photographs of a living giant squid were taken.

We talked about the giant squid in episode 74 and we talked about some other types of huge squid in episode 235. I’m willing to bet that there are even larger squid living their quiet squid lives in the depths of the ocean, just as there are probably jellyfish larger than any human has ever seen. Let’s just hope they leave ships and boats alone.

You can find Strange Animals Podcast at strangeanimalspodcast.blubrry.net. That’s blueberry without any E’s. If you have questions, comments, or suggestions for future episodes, email us at strangeanimalspodcast@gmail.com. If you like the podcast and want to help us out, leave us a rating and review on Apple Podcasts or Podchaser, or just tell a friend. We also have a Patreon at patreon.com/strangeanimalspodcast if you’d like to support us for as little as one dollar a month. This month’s Patreon episode is about two hikers in the Pyrenees Mountains who heard a ferocious, terrifying roar out of the darkness near their camp.

Thanks for listening!

Episode 054: Regenerating Animals

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This week we’re going to learn about animals that can regenerate parts of their body. What animals can do it, how does it work, and can humans figure out how to make it work for us too?

Thanks to Maxwell of the awesome Relic: The Lost Treasure podcast for suggesting this week’s topic!

The planarian, not exciting to look at but you can get a lot of them easily:

A starfish leg growing a new starfish, or possibly a slightly gross magic wand. Ping! You’ve been turned into a magical starfish:

The adorable axolotl:

The almost as adorable African spiny mouse:

A hydra. Not really very adorable except possibly to other hydras but kind of pretty:

Show transcript:

Welcome to Strange Animals Podcast. I’m your host, Kate Shaw.

This week’s episode was going to be about lungfish, but I had to postpone it because I ran across some conflicting information about a mystery lungfish, which required me to order a book that probably won’t arrive for a week or two. So when I tweeted about needing a new topic quick, Maxwell of the Relic: The Lost Treasure podcast suggested animals that can regenerate parts of their bodies.

We’ve touched on regenerative abilities before in one or two episodes. Some lizards can drop their tail if threatened, which then regrows later—but a lizard can only do that once. The fish-scaled gecko from episode 20 can lose its scales and regenerate them repeatedly. But other animals can regenerate not just bits and pieces, but entire organs and even their brains. The sea lamprey can even regenerate spinal cord cells. You better believe researchers are trying to figure out how regeneration works and if it can be adapted for human application.

A lot of worms can regenerate lost pieces, including earthworms. Whenever I’m gardening and accidentally cut an earthworm in half with the shovel, I reassure myself that the worm will regenerate the end I cut off. Some species can even grow back from both cut pieces, effectively turning one earthworm into two, depending on where it is severed, although that’s rare. Some species of worm can only regrow the tail, but some can regrow the head. And some, of course, can’t regrow anything. Leeches are a type of worm but they can’t regenerate at all.

Planarians are flatworms. Some species live in water, some in damp areas on land, but they can all regenerate. If you cut a planarian in two, each half will regenerate into a new planarian. If you cut a planarian in three, you’ll get three planarians. Cut one into four, you get four planarians, and so on and on. Researchers with a lot of time and patience have determined that you can cut a planarian into as many as 277 pieces and you will get 277 planarians after a few weeks. But I guess if you cut a planarian into 278 or more pieces, some of the extra pieces won’t do anything.

Starfish are well-known to regenerate lost or injured legs, and may even drop a leg to escape from predators the way some lizards drop their tails. Some species of starfish can regrow an entire starfish from a single limb. That’s oddly creepy. I don’t know why I find it so creepy. I don’t find the planarians creepy. It’s like if I was run over by a motorboat that chopped my arms and legs off, and instead of dying I not only regrew my arms and legs, my severed arms and legs each grew a new me. I don’t think I’d like that. Although I’m not going to get in the water so I doubt I’ll be run over by a motorboat, and also if I was, sharks would probably eat me before we could see if any parts regrew.

Many starfish relations, such as sea urchins and sea cucumbers, can also regenerate body parts. When the sea cucumber is threatened, it can and will eject its internal organs. They’re sticky and full of toxins, which deters predators, and the sea cucumber just regenerates them.

Most crustaceans, such as crabs and krill, can regenerate legs. So can spiders, which may drop legs to escape from predators. That’s called autotomy, by the way, when an animal detaches a body part to escape from a predator. Spiders molt their exoskeletons every so often as they grow, and lost limbs grow back after molting. Sometimes it takes a few molts for the leg to be the same size as the other legs. Spiders can also regenerate other lost or damaged parts, including mouthparts and spinnerets.

Salamanders and newts can regenerate limbs, tail, some organs, jaws, even parts of their eyes. Frogs and other amphibians can’t. Likewise, some fish can regenerate injured tissue, such as the zebrafish which can regrow fins and eye retinas, and some species of sharks that can regenerate skin tissue, while others can’t. The axolotl, which is an adorable rare salamander found in Mexico, can regrow just about any part of its body, including its spinal cord and up to half of its brain.

So what about mammals? Do any mammals have regenerative capabilities? As a matter of fact, yes. The African spiny mouse is the big regenerator among mammals. It’s actually more closely related to gerbils, and it has stiff guard hairs all over its body that stick out and make it look fuzzy but which act as spines to help ward off predators. But if a predator attacks anyway, three species of the spiny mouse can autotomically drop off part of its skin, which later grows back. Some species of spiny mouse are kept as pets, even though they don’t do very well in captivity. The pet species don’t have regeneration abilities, incidentally. However, they do have delicate tails that are easily injured, which they then lose, and the tail does not grow back.

Those three species of African spiny mouse can also regenerate ear tissue. If a spiny mouse’s ear is damaged, even if it has a hole as big as four mm across, it can regenerate the ear as good as new rather than heal it with scar tissue. A number of mammals can regenerate small injuries to ear cartilage under the right circumstances, including cats. Rabbits can also regrow damaged ear tissue, and have some other regenerative abilities too.

It’s all well and good to point out that a whole lot of animals can regenerate lost or damaged body parts. But how does it work? And more to the point, why can’t humans do it?

Technically, humans and other animals are regenerating certain cells all the time, especially skin cells and blood cells. Small cuts and scrapes heal up without scarring and we don’t think about it at all. Fingertips will grow back after injury and the liver can regenerate. The endometrium, which is the lining of the uterus, is partially reabsorbed into the body and partially expelled from the body every month during menstruation, then regrows. Toenails and fingernails regrow after injury. We just don’t think about all these things because they seem normal to us, whereas we can’t regrow a whole finger if it’s been chopped off, for instance.

I won’t go too deeply into how regeneration works, mostly because it’s complicated and I don’t want to screw it up too badly. There are also different types of regenerative abilities with different processes. Basically, though, as an example, when a salamander loses a leg, the cells surrounding the wound dedifferentiate, basically turning from regular skin cells or what have you into stem cells that can grow into anything the body needs. These cells form what’s called a blastema, which is just the fancy name for a bundle of dedifferentiated cells. Then the blastemal cells start differentiating again, this time into the cells needed to regrow the leg, just as stem cells grew legs when the salamander was developing in its egg.

It sounds pretty simple, put like that. I mean, that’s how we all develop in the first place, from a fertilized egg into a person who can make podcasts and eat cupcakes. The main problem is figuring out how to get human cells to dedifferentiate into a blastema. Because it’s not just injuries that could be helped if scientists figure this out, it’s all sorts of problems. People who have lost their sight due to retinal diseases could regrow new retinas. People born with birth defects could have the nonstandard parts regrown so that they work the way they’re supposed to.

Researchers are working hard to figure all this out. Stem cell research is a big part of regenerative research. Unfortunately, at some point the rumor started that all stem cells come from babies, specifically embryonic stem cells. When a human egg is fertilized, after a couple of days a blastocyst is formed from the cells, which is similar to a blastema but made of cells that have never differentiated into anything else. They’re brand new cells with the capacity to make a brand new human. Naturally, people are squiffy about taking cells that might make a baby and using them for something else. But amniotic fluid, the fluid that surrounds the baby as it’s growing in its mother, also contains stem cells, and they can be harvested without hurting the baby or the mother. You can also get stem cells from the umbilical cord right after a baby is born, and the umbilical cord is just cut off and thrown away anyway so you might as well give it a little extra use. But most stem cells used in research and treatment these days come from bone marrow, lipid cells in fat tissue, and blood, all of which can be extracted without harming the person. They’re not as powerful as embryonic and amniotic stem cells, but they have the benefit of being from the patient’s own body, so no immunosuppression is required to make sure the body accepts them in stem cell treatment.

That was a lot of confusing medical information, so let’s talk about one more animal that can regenerate, the hydra. We’ve talked about the hydra before in the jellyfish episode, which for a long time was our most popular episode. It’s now our second-most downloaded episode, with our first episode inexplicably in the top spot. The hydra is a freshwater animal related to jellies that can regenerate so completely it’s essentially immortal.

The hydra is related to the so-called immortal jellyfish we talked about in episode 19. It can regenerate just about any injury, and like the planarian it can regenerate into more than one copy of itself if it’s cut up into tiny pieces. It’s only a few millimeters long but its tiny body is full of stem cells, and as long as stem cells are present in the body part that was cut off, an entirely new hydra can grow from it. Because of its amazing regenerative abilities, some admittedly controversial studies suggest the hydra doesn’t age. That’s a neat trick, if you can manage it.

You can find Strange Animals Podcast online at strangeanimalspodcast.com. We’re on Twitter at strangebeasties and have a facebook page at facebook.com/strangeanimalspodcast. If you have questions, comments, or suggestions for future episodes, email us at strangeanimalspodcast@gmail.com. If you like the podcast and want to help us out, leave us a rating and review on Apple Podcasts or whatever platform you listen on. We also have a Patreon if you’d like to support us that way.

Thanks for listening!

Episode 041: Comb Jellies and Sea Sponges THE CONTROVERSY

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We’re learning about comb jellies this week, along with the sea sponge, and the MASSIVE CONTROVERSY ABOUT THE TWO THAT IS PITTING SCIENTIST AGAINST SCIENTIST I might be overstating it just a bit

The lovely Arctic comb jelly:

The lovely Venus’s girdle comb jelly:

A fossil comb jelly. Probably lovely when it was alive:

A sea sponge (most are not this Muppet-like):

Show transcript:

Welcome to Strange Animals Podcast. I’m your host, Kate Shaw.

For this week’s episode, we’re revisiting jellyfish, more properly known as jellies. The first jelly episode is far and away our most popular and I can’t figure out why. I mean, I’m glad people like it. This time, we’re going to learn all about comb jellies, which are not really as exciting as true jellies. There is no ship-sinkingly enormous comb jelly lurking in the oceans of the world. But they are really interesting.

When you think of a jelly, you probably picture a roughly bell-shaped thing with long stinging tentacles. But most comb jellies are more like egg-shaped blobs, and either don’t have tentacles at all or only have relatively small tentacles that don’t sting. Although they look alike superficially, comb jellies and true jellies are so different that scientists don’t think they’re very closely related at all. Comb jellies are officially called ctenophores (TEN-oh-fours), spelled with a c-t at the beginning if you were wondering. I looked up the pronunciation. Yeah, I know, I pronounced Pliny wrong all through episode 12, but come on, it looks like it should be pronounced Pliny and not Plinny. It’s not like anyone ever came up to me and said, “Hey, what about that Plinny, what a guy.” I just read the name.

But I digress, inexplicably.

Instead of pulsing its bell to maneuver in the water, a comb jelly has rows of tiny compact filaments called cilia, fused together in combs that help it swim. The combs are also called swimming plates.

There are two main types of comb jellies, those with tentacles and those without tentacles. The ones without are called Nuda, or Beroids, and while they don’t have tentacles, they do have combs of extra-large cilia, called macrocilia, that sever prey into pieces small enough to swallow. Mostly they eat other comb jellies. Beroids also have big mouths, but a beroid can actually seal its mouth shut while it’s moving so it’s more streamlined.

Comb jellies with tentacles are divided into eight orders roughly based on body shape. The most common order, the cydippida, are egg-shaped with a pair of thin tentacles that they use sort of like fishing lines. The tentacles are long and sticky, trapping tiny organisms or particles of food. Some species have branched tentacles but none have more than two. The tentacles can retract—when you see a picture of a comb jelly with a weird spring-like thing sticking out from its bottom, that’s a retracted tentacle, not anything gross like a poop. The tentacles contain cells called colloblasts. When an organism touches a tentacle, the colloblast cells rupture and basically release glue that keeps the prey from escaping.

A cydippid comb jelly also has eight combs that run from the top of the body to the bottom, which makes it look sort of like a fancy decorated egg. Comb jelly cilia are iridescent, by the way, so they reflect light in rainbow patterns. Basically what I’m saying is, these little guys are actually really pretty.

All comb jellies are predators, but most eat plankton and other tiny food, because most comb jellies are really small—only a few inches long at most. Bigger species may eat krill and small crustaceans. The biggest comb jelly, Cestum veneris, more often called Venus’s girdle, can grow some five feet long, or 1.5 meters, but only some two inches, or 5 cm, wide. It looks like a nearly transparent or purplish ribbon and lives in tropical and subtropical seas. I wouldn’t want to touch it, but it’s not exactly dangerous. In fact, it’s so delicate that a diver attempting to touch one may accidentally destroy it instead. A lot of comb jellies are that delicate, making them hard to study, so we still don’t know a whole lot about them.

Comb jellies only have one body opening, called a mouth for convenience sake although the jelly uses it for anything that requires a body opening. Until recently, researchers thought that included pooping. Yeah, now you see why it’s not exactly a mouth. But it turns out that a comb jelly has pores on the opposite end of its body from its mouth opening that it uses to release at least some particles of indigestible food. This is interesting since it helps scientists understand how the anus evolved.

There aren’t that many species of comb jellies, maybe 100 or so. But new ones are discovered occasionally, especially deep-sea comb jellies. While comb jellies that live near the surface of the ocean are usually transparent, many deep-sea species are red, since it’s a color most deep-sea animals can’t see. Most are also bioluminescent, and when threatened some species will secrete a luminescent goo. The predator may get confused and attack the goo while the comb jelly swims away as fast as its frantically waving cilia can take it.

If you’ve listened to episode 15, about the hammerhead shark and megalodon, you’ll remember that we don’t have a lot of shark fossils because shark skeletons are made of cartilage, not bone. We just have a lot of shark teeth, mostly. Now think about how big and solid sharks are, then think about how smooshy jellies are. Then try to imagine what a jelly fossil might look like. Yeah.

We do have some comb jelly fossils, though. But we don’t have many. Like, five. We have five. The oldest are from the mid-Cambrian, some 500 million years ago, but they were very different from the comb jellies living today. They had lots more combs, for one thing—between 24 and 80 instead of 8. Researchers have found other fossils that may be of comb jellies. There’s a good possibility that they were widespread throughout the oceans back then—but from genetic testing and other molecular analysis, it appears that the comb jellies alive today are all descended from a common ancestor that survived the Cretaceous-Paleogene extinction around 65 million years ago. So it’s possible that in addition to so many dinosaurs dying off, almost all comb jellies went extinct then too.

Just think, if that one species hadn’t survived and evolved into the comb jellies we have today, researchers might not have a clue what animal those comb jelly fossils represented. If you know about the Burgess shale fossils that have baffled and fascinated paleontologists for decades now, because so many of the fossils don’t resemble anything living today, then it’ll make sense to learn that a few of those five comb jelly fossils were actually found in the Burgess shale.

There are some other comb jelly fossils discovered in China and dated to 520 million years ago. But they don’t resemble the comb jellies living today at all because they had skeletons and spines. Pretty much every fossil found from the Cambrian had supportive or armored structures, even ones like comb jellies that don’t have those things today. I’ll probably do a whole episode eventually about the Cambrian period and the Burgess shale discoveries.

Anyway, there’s some controversy going on right now regarding whether comb jellies or sponges were the species that gave rise ultimately to all other animals, so let’s take a quick side trip and learn about sponges.

The sponge is a very simple animal, still around today. They don’t have any specialized structures like nerves or a digestive system or a circulatory system or organs. They’re just a sponge, basically. And if you were wondering, the sponge you use to clean your kitchen is named after the sea sponge, not vice versa, and you can still get actual dried sea sponges to use for cleaning. They’ve been used that way for millennia. It wasn’t until 1866 that scientists even realized sponges were animals and not plants.

Living sponges just hang out in the ocean or freshwater, stuck to a rock or something. Water flows through them and washes food and oxygen in and waste out. That’s it. That’s all a sponge does is let water flow through it. I feel like there’s a life lesson to be learned there, but I’m too busy doing ten things at once to figure it out.

Mostly sponges eat bacteria and other tiny food particles, although some eat small crustaceans and a few have developed a symbiotic relationship with plantlike microorganisms, which live safely in the sponge and produce enough food for both it and the sponge. Every so often a sponge will release eggs or sperm into the water. If the conditions around a sponge deteriorate, some species will create bundles of unspecialized cells called gemmules. When conditions improve, the gemmules will either grow into new sponges or, if the sponge that created them has died, it will recolonize the original sponge’s skeleton.

A sponge’s skeleton is a sponge, by the way. If you’ve got a natural sea sponge in your house, that’s what you’re cleaning your kitchen counters with, the skeleton of a sea sponge. Different sponges use different minerals to create their skeletons and most are pretty hard, but the ones sold as natural sponges are softer and throughout history have been used for everything from padding armor, applying paint, and filtering water. Loofah sponges aren’t actually made from sea sponges, though. They’re actually from the dried insides of the sponge gourd. I did not actually know that until just now.

Oh, and guess what else I just learned? There’s a small population of bottlenose dolphins in Western Australia that use sponges. The dolphins frequently hunt close to the bottom of the bay. To keep from scraping its rostrum, or bill, in the sand, a dolphin will sometimes stick a sponge under its chin. Researchers think that one especially smart dolphin figured this out and has been teaching her children how to do it ever since.

So that’s the sea sponge. Useful for many things, not much of a party animal. Compared to sea sponges, comb jellies are intellectual masterminds. Even though comb jellies don’t have brains.

Instead, comb jellies have a nerve net. The nerves are concentrated around its mouth and on its tentacles. It does also contain an organ that helps the jelly sense its orientation, basically so it knows which way is up. It usually swims with its mouth pointing upward, incidentally. But while the comb jelly’s nervous system is pretty sophisticated for such a simple animal, it’s also very different from other animals’ nervous systems. Like, super different. Its nerves are constructed from different molecules and use different neurotransmitters.

Its nerve cells are so different from other animals’ that some researchers think it actually evolved separately. Specifically, neuroscientist Leonid Moroz thinks so. He thinks that the first ancestor of comb jellies split off from the sea sponges some three quarters of a billion years ago and evolved separately from all other animals.

Since comb jellies use a different set of chemicals as other animals to accomplish the same tasks, a couple of articles I read make a big deal about how evolution must therefore follow a prescribed path—that animals must have certain traits to survive. But assuming comb jellies did split off from sponges that early and did evolve separately from other animals, they were still competing against those other animals. It’s not like they had an ocean to themselves, although that would be awesome if they did, because who knows what they might have evolved into?

The controversy about whether sea sponges or comb jellies were basically the trunk of the tree of animal life started in 2008, when a study in the journal Nature compared DNA sequences across a number of animal species and suggested that the comb jellies were evolutionarily first. A 2013 paper published in Science by another team of researchers made the same conclusion based on the genome of a species of comb jelly called the sea walnut. That is such a cute name. Don’t you just want to cuddle the little sea walnut and make little hats for it?

All this ignited what some articles call a firestorm of controversy. I like to imagine researchers reading the articles and FREAKING OUT. Moroz’s studies of the comb jelly’s nervous system, and the complete genome of a different comb jelly, the sea gooseberry, appeared in Nature in 2014. Moroz now thinks that nervous systems have developed independently at least nine times in various different groups.

The controversy at this point appears to have several factions. Moroz’s group thinks comb jellies split off from sponges, and that everything else split off from comb jellies but developed separately in the neurological sense. Another group thinks comb jellies split off from sponges and everything evolved from comb jellies, and that comb jellies aren’t all that weird neurologically. Another group thinks comb jellies and sponges split off from a common ancestor of both that had a simple nervous system, which comb jellies retained but sponges lost, and that everything else evolved from comb jellies. But then there’s the other side, the ones who think sure, comb jellies split off from sponges, but so did everything else ultimately, and comb jellies are no more the base of all animal life than the man in the moon.

One thing everyone agrees on, though, is that we still don’t know enough about comb jellies. And they are really pretty.

You can find Strange Animals Podcast online at strangeanimalspodcast.com. We’re on Twitter at strangebeasties and have a facebook page at facebook.com/strangeanimalspodcast. If you have questions, comments, or suggestions for future episodes, email us at strangeanimalspodcast@gmail.com. If you like the podcast and want to help us out, leave us a rating and review on iTunes or whatever platform you listen on. We also have a Patreon if you’d like to support us that way. Rewards include stickers and twice-monthly bonus episodes.

Thanks for listening!

Episode 016: Jellyfish

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If you look at this episode and think, “Oh, ho hum, think I’ll skip this one because snore, jellyfish,” you are so wrong! Jellies are fascinating, creepy, and often beautiful. Come learn all about our squishy friends in the sea!

A Portuguese man o’war. Creepy as heck:

A lion’s mane jelly. You do not want this guy on your ship. Incidentally, a lot of the photos you find of divers with enormous lion’s mane jellies are fakes that make the jellies look gigantic.

The cosmic jelly, a deep-sea creature:

The creepy Stygiomedusa gigantea, guardian of the underworld:

A newly discovered golden jelly.

Further reading:

Jelly Biologist (I’ve been enjoying browsing this site)

Show transcript:

Welcome to Strange Animals Podcast. I’m your host, Kate Shaw.

This week’s episode is about jellyfish—also called jellies, which is more accurate since they’re not fish at all.

Originally, I was going to focus on the Portuguese man o’war, another in the ongoing feature of “animals that scared me as a kid” and technically not even a jelly. But there’s so much to learn about jellies that we’re going to cover a whole lot more than that.

Jellies are interesting animals, to say the least. Their bodies have radial symmetry, meaning they’re the same in all directions. While the body shape varies, most jellies have a bell-like shape. The bell is generally rather thin, made up of an external covering, an internal covering, and an elastic gel-like material in between. Inside, the jelly has a digestive cavity with four to eight oral arms surrounding the mouth and long tentacles hanging beneath. The jelly also has a simple nerve net that can detect light and react to other stimuli, and which takes the place of a brain.

Jellies don’t have brains. They don’t have hearts, specialized sensory organs, or much of anything else. But they’ve been around for some 650 million years, possibly much longer, so clearly it all works.

The jelly’s life cycle is pretty weird. Most start out as polyps that stick to rocks or shells and use their little tentacles to catch microscopic organisms. A polyp can bud, producing new polyps that are clones of the original. Eventually, a polyp will constrict its body and develop into a stack of larvae. Each larva develops into a tiny jelly, which separates from the stack and swims away.

Once it’s grown, a jelly reproduces by releasing sperm, if it’s male, which the water carries to the female to fertilize her eggs. Some female jellies have brood pouches on the oral arms, some just carry the fertilized eggs inside the body while they develop. The embryos develop into swimming larvae called planula, which leave the female and attack themselves to something firm, where they transform into polyps.

This seems needlessly complicated, but again, it works for the jelly.

Polyps can live for years, while adult jellies, which I’m delighted to report are called medusas, usually only live a few months. The immortal jellyfish throws another step into this process. It can transform back into a polyp from any stage of its life if it needs to. As a polyp, the immortal jellyfish is tiny, only about a millimeter long. As a full-grown medusa it’s not all that much bigger, less than four millimeters in diameter. Because it can transform back into a polyp as many times as it needs to, apparently without any kind of degradation or injury, the immortal jellyfish is effectively, well, immortal.

Before you get too excited, though, keep in mind that there’s not a whole lot of research into the immortal jellyfish yet. It’s not even known if they will transform back into polyps in the wild, since it’s only ever been observed in captivity.

Almost all jellies have stinging cells, usually concentrated on the tentacles or oral arms, which they use to stun and kill prey. The stinging cells contain venom-filled nematocysts, which are coiled structures that uncoil and sting when touched. Humans are not jelly prey, but jelly stings can still be uncomfortable—and sometimes fatal—to humans.

You’ve probably heard of the infamous box jellyfish, the most dangerous species of which is common around Australia. Unlike most jellies, box jellyfish have true eyes and a relatively well-developed nervous system. They’re active, hard for humans to detect while swimming since they’re nearly transparent, and in the case of Chironex fleckeri, their venom can kill a human in as little as two minutes. Most fatalities occur in children, but most stings don’t result in death.

Another vicious and occasionally fatal stinger is the Portuguese man o’war, although it isn’t actually a jelly. It’s not even a single animal, it’s a colony. One member is the float, another the feeding polyps, and so forth. The man o’war takes its name from a type of ship, which the float somewhat resembles. The float is bluish or purplish, generally under a foot long [30 cm], and filled with gas. Underneath the float are feeding polyps from which hang purple tentacles, typically around 30 feet long [9 m] but sometimes up to 200 feet long [61 m]. If something attacks the man o’war, it can vent some of the gas in its bladder and submerge temporarily.

When I was a kid, my family occasionally went to the beach in North Carolina. Man o’wars are tropical animals but they do occasionally drift farther north. I was fully aware of this as a kid and did not want to get in the water farther than my waist. My grandfather and one of my aunts reassured me that they’d both been stung by a man o’war once, and it wasn’t any more painful than a wasp sting.

That did not make me feel any better. In fact, it made me even more scared because then I KNEW there were man o’wars out there. I wasn’t afraid of being stung, I was afraid of touching those creepy tentacles.

As it happens, my grandfather and Aunt Barbara probably had not encountered a Portuguese man o’war but a smaller animal called a by-the-wind sailor, which is now my favorite name of anything. It has a blue bladder float like the man o’war, but its sting is much milder, A man o’war sting is incredibly painful, more of a shock, that can lead to intense muscle and joint pain, open wounds on the skin at the sting site, headache, chills and fever, nausea, and can cause victims to faint and drown. Occasionally the venom travels to the lymph nodes and causes even more serious symptoms, including swelling of the larynx, an inability to breathe, and cardiac distress. Even a dead man o’war can sting if you touch its tentacles. Why would you touch its tentacles.

I’m not the only one who feels this way about man o’wars, clearly, because one of its other names if the floating terror. That sounds like the title of a pulp science fiction novel.

The bluebottle is a smaller related species found in the Indian and Pacific Oceans. The man o’war is found in those oceans and the Atlantic. A few weeks ago, in early May 2017, hundreds of man o’wars washed ashore in Georgia and South Carolina. Man o’wars are pretty common around Florida, especially in winter, and occasionally they wash ashore in the thousands.

The man o’war eats fish and other organisms that get caught in the stinging tentacles, but there are some fish that live among the tentacles, even feeding on them, like the man o’war fish and the clownfish. Not a lot of things eat Portuguese man o’wars, but the loggerhead turtle and ocean sunfish do. I like them both. The blanket octopus is immune to the man o’war’s venom and may carry broken-off tentacles to deter predators.

If you’re stung by a man o’war, treat the sting the same way you’d treat other jelly stings. Rinse with vinegar to remove any remaining bits of tentacle or nematocysts, then apply heat for 45 minutes, either with a hot pack or by immersing in hot water. Don’t rinse with urine or vodka; it can make the stings worse—and definitely don’t rinse with fresh water. If you don’t have vinegar, rinse with sea water, but keep in mind that you may be pouring nematocysts back onto the patient with the water. This treatment is from a very recent study conducted by researchers at the University of Hawaii at Manoa, released only a few weeks ago as this episode goes live, so if you’ve heard differing advice for jelly stings, it may be out of date.

Jellies are related to some surprising things: coral, sea anemones, a rare parasitic worm, the freshwater hydra—a ten mm long tubular animal with stinging tentacles at one end that it can stretch four or five times the length of the body to catch its tiny prey. Like jellies, the hydra can regenerate parts of its body if they’re injured or bitten off. And the hydra doesn’t appear to age, making it biologically immortal, although in a different way than the immortal jellyfish.

So what’s the largest jelly known, not counting ridiculously long tentacles like the man o’war’s? That would be the lion’s mane jellyfish. Its bell can have a diameter of over seven feet [2 m] and it has pretty darn long tentacles, too—sometimes over 120 feet long [36.5 m]. It likes cold water and the biggest individuals live where it’s coldest. While small individuals are brown or tan in color, the big ones are usually red or purple. The sting of a lion’s mane jellyfish isn’t usually that bad, but it has a lot of tentacles, so it can inflict thousands of stings upon contact.

In 1973, the Australian ship Kuranda collided with a huge jelly in the South Pacific while traveling through a storm on her way to the Fiji Islands. The jelly was so enormous that the deck was covered in jellyfish goo and tentacles up to two feet deep [61 cm]. One crew member died after getting stung. The weight of the jelly was so great, an estimated 20 tons [18 metric tons] that it started to push the ship nose-down and the captain, Langley Smith, sent out an SOS. The salvage tug Hercules arrived and sprayed the Kuranda’s deck with a high-pressure hose, dislodging the jelly. Samples were sent to Sydney and tentatively identified as a lion’s mane jelly.

But remember, lion’s mane jellies don’t live in the warm waters near Fiji and Australia. There are other reports of lion’s mane jellies seen in the area, though, so it’s possible there’s a gargantuan warm-water variety that hasn’t been discovered yet.

Most jellies live near the surface of the ocean, but there are some deep-sea species known, with more being discovered every year. A gorgeous jelly, dubbed the cosmic jellyfish by the press, was spotted 9,800 feet [2987 m] below the surface near American Samoa this February. It has an umbrella-like bell with short tentacles that point both downward and upward. You may have seen it in the news described as looking like a flying saucer, which it does. A similar jelly was discovered in the Mariana Trench in 2016, almost two and a half miles underwater [4 km]. These are lovely jellies with translucent bells and glowing red and yellow innards, but there are less lovely ones down there.

The big red jellyfish discovered in 2002 is an ugly cuss. It lives in waters up to 4900 feet deep [1493 m] and is over a foot in diameter [30 cm]. It’s dull red in color and doesn’t have tentacles, just thick oral arms.

Stygiomedusa gigantea, also known as the guardian of the underworld by at least one website, and now by me, isn’t so much ugly as horrifying. Its bell is some three feet across [1 m], and while it doesn’t have tentacles or even stinging cells, it does have four 30-foot-long [9 m] oral arms that resemble dark brown or reddish strips of cloth that drift in the ocean currents.

Some deep-sea jellies don’t have tentacles or oral arms. Deepstaria enigmatica, a rare jelly described in 1967, basically just looks like a big mesh bag. Its close relative, Deepstaria reticulum, is very similar, but it’s reddish instead of whitish. The Deepstaria hangs motionless in the deep with its three-foot-wide [1 m] bell open, waiting for something to swim into it. When it does, the bell contracts like a bag, the fish or other organism is stung by nematocysts lining the bell, and the jelly pushes its stunned prey into its mouth with tiny cilia inside the bell.

Isopods, which are small crustaceans, frequently hitch rides inside Deepstaria bells. It’s not known if they’re parasites or confer some benefits to the jellies, but they don’t seem to be affected by the stings.

There are plenty of mysteries associated with enormous jellies, although the two most famous ones I dug into started to seem less and less likely once I got closer to the primary sources. According to Eric Frank Russell in his 1957 book Great World Mysteries, in 1953 a diver testing a new type of deep-sea diving suit in the South Pacific saw an enormous jelly-like monster kill a shark. The diver had been testing how deep he could dive in the suit and noticed a fifteen-foot [4.6 m] shark following him down. I’m going to quote the relevant section instead of paraphrasing, because it’s pretty amazing.

“The shark was still hanging around some 30 feet [9 m] from me and about 20 feet [6 m] higher, when I reached a ledge below which was a great black chasm of enormous depth. It being dangerous to venture farther, I stood looking into the chasm while the shark waited for my next move. Suddenly the water became distinctly colder. While the temperature continued to drop with surprising rapidity, I saw a black mass rising from the darkness of the chasm. It floated upwards very slowly. As at last light reached it I could see that it was of a dull brown color and tremendous size, a flat ragged-edged thing about one acre in extent. It pulsated sluggishly and I knew that it was alive despite its lack of visible limbs or eyes. Still pulsating, this frightful vision floated past my level, by which time the coldness had become most intense. The shark now hung completely motionless, paralyzed either by cold or fear. While I watched fascinated, the enormous brown thing reached the shark, contacted it with its upper surface. The shark gave a convulsive shiver and was drawn unresisting into the substance of the monster. I stood perfectly still, not daring to move while the brown thing sank back into the chasm as slowly as it had emerged. Darkness swallowed it and the water started to regain some warmth.”

I am skeptical, I admit. Eric Frank Russell was primarily a science fiction writer and this sounds like something from a novel, probably one called The Floating Terror. If he described the monster as 20 feet across or even 30 or 40 [6, 9, 12 m], I’d be going, “Hmm, but hey, the deep sea is full of amazing things.” But an acre? That’s 208 feet 9 inches across. 43,450 square feet. A lot of meters [4,046 square meters]. It’s three times the size of my yard, which takes me like an hour to mow. It’s just too big to believe, not without corroborating details—like a first-hand account of the actual diver. We don’t even know his name. And what about the diver’s buddy? Divers don’t go down alone, although maybe they did back in 1953. The whole story is just too thin, too fantastical to be believed.

The other promising mystery I looked into is a supposed legend from Chile, a sea monster that resembles a cow hide stretched flat but with eyes all around the edges and four big eyes in the middle. It rises to the ocean’s surface and swallows animals it encounters.

At first glance this sounds ridiculous, until you realize that many jellies have semi- or fully transparent bells and their internal organs, such as they are, may resemble eye-like blobs in the center of their bodies. Some jellies do have light-sensitive eye spots near their edges too. But the research I did to follow up this story, which I took from Karl Shuker’s blog, but which is originally from Jorge Luis Borges’ 1969 book called The Book of Imaginary Beings, indicated that the actual legend is much different and much less jelly-like.

El Cuero is a cowhide monster called Threquelhuecuvu among the Mapuche of Patagonia. It lives in rivers, lakes, and the ocean. It’s nearly circular, has claws around its edges, and one pair of red eyes. It also has tentacles on its head and a mouth in its middle, which it uses to suck bodily fluids from its prey. It’s supposed to come out of the water and come on land, and when an animal steps on it, it wraps its body around the animal and suffocates it. Then it drags its prey into the water to eat it. The only way to kill it is to throw cacti into the water. When the monster grabs the cacti, it’s pierced through with spines and dies.

It’s generally supposed that the monster is based on freshwater stingrays, although they’re not known to live in Patagonia. But in 1976, after a bus full of tourists ended up on the bottom of Lake Moreno, divers who retrieved the drowned victims reported enormous rays in the depths.

There is a freshwater stingray species in South America which has thorn-like denticles on its body and a closely related species, also with denticles, sometimes travels upriver from the ocean off the Chilean Patagonian coast. That might be the source of the cowhide monster.

So those two mysteries are almost certainly bust. But don’t feel discouraged. Not only was that 20-ton ship-sinking 1973 lion’s mane jelly a real, documented thing that happened [note from episode 248: sorry, it turns out it wasn’t real], there are lots of jelly species being discovered all the time.

Not all are deep-sea species. In 2013, a fisherman in northeast Italy hauled up a net full of golden jellies he’d never seen before. He contacted the local university, and a researcher came out and determined that the lovely golden jellies were completely unknown to science. In 2015, a 9-year-old boy caught a new species of box jelly that’s only around an inch long [3 cm].

There are freshwater jellies too, but not a lot is known about them. To add to the confusing and complex life cycle of marine jellies, many freshwater jellies also have a dormant stage where they basically turn into tiny jelly seeds, tough and capable of surviving even if dried out.

And back in the Cambrian era, some 500 million years ago, some jellies actually had skeletons. Fossil impressions show plates, spines, and spokes from comb jellies, which today are completely soft-bodied. Comb jellies are different from the kind of jellies I’ve mostly talked about in this episode, and not even closely related to them. I’d dig into them next, but we’re already pushing 20 minutes and there’s a limit to how much jellyfish information I can expect my listeners to tolerate in one sitting. We’ll save the comb jellies for another episode.

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