Zefrank1 has just come up with another “educational” video about a weird creature, the sea pig, a group of holothurians (sea cucumbers; genus Scotoplanes) in the phylum Echinodermata, which also includes starfish and sea urchins. It is in fact the only holothurian with “legs,” which are homologous to the tube feet of starfish and have become large and able to be inflated with water. They can be seen as analogous to vertebrate legs (they do the same thing) but not homologous to them (they have independent evolutionary origins based on different genes).
Another true fact: I’ll eat almost anything, but reject the odious sea cucumber, which is a staple of Chinese cooking. It is in fact the most disgusting thing I’ve ever put in my mouth.
Hilarious! What a nifty little guy.
Lovely! I don’t think I’ve watched this series before, I like their creative take 🙂
“genus Echinodermata”??
That obvious mistake was fixed before I saw your comment!
Pretty funny, and factually accurate to boot.
But yeah, the really cool thing about sea pigs is that they evolved walking-with-legs independently of the arthropods and tetrapods (btw, the Phylum Echinodermata is much more closely related to us than are the arthropods). There’s another group of pelagic holothurians that has independently invented swimming, too. In both groups the increased motility has favored the re-evolution of bilateral symmetry (nearly all other echinoderms, including sea cukes, are pseudo-radially symmetrical). For example, the ‘front’ end of a sea pig is homologous to the bottom of a starfish or sea urchin.
Thank you for the additional information. Putting sea pigs in an evolutionary context makes them even more interesting.
“But yeah, the really cool thing about sea pigs is that they evolved walking-with-legs independently of the arthropods and tetrapods”
The appendages are articulated, making them more similar to the cephalopds arms than to the limbs of arthropods or vertebrates. I suppose they function like starfish arms, by changes in hydraulic pressure.
Desnes Diev
Fascinating and funny–what a great approach! I want to meet the narrator’s Mom; she sounds full of pithy wisdom!
But, “true facts”? Add that to the list of phrases we can do without.
In light of the narrator’s great sense of humour, it suits him to a T. 🙂
The ‘true facts’ thing is itself part of the joke.
Look into more of ZeFrank’s ‘True Facts’ series and you’ll know what I mean.
They’re not to be taken entirely seriously.
I particularly like True Facts About The Chameleon.
Now I’m going to have to watch every one of his videos!
Now I’m going back and watching them again too. ^_^
True Facts About The Fruit Bat had me laughing again.
A minor quibble, but Scotoplanes isn’t the only holothurian to get around on “legs”. This structural adaptation and mode of locomotion is widespead among the deep-sea holothurian Order Elasipodida. They are remarkable creatures. As the most abundant large sediment-grazers of the deep-sea floor they’re arguably among the most successful groups of animals on Earth, although known to few people other than deep-sea biologists.
I was just struck by an insatiable curiosity to learn some ‘false facts’ about sea pigs…
Trust me, this sea cucumber (when cooked) is my favourite dish!!! and it is not cheap – it is a delicacy yum yum! You just need to try it once!!!
I’m not sure how #8, T.S.Chuan, prepared his dish but I can attest to enjoying a part of the sea cucumber which once removed and sautéed tastes like a wonderful clam strip. Standard cuisine of the Pacific Northwest coast! Please check this out; it hurts to think a gourmand such as yourself is missing this!!
I used to tag along with a marine zoology class that would go to Puerto Penasco, Mexico. We would have lots of fun turning over rocks at low tide, looking for critters. Big sea cucumbers were common. We would pick them up and play with them precisely b/c they looked like big soft turds… well you had to be there I guess. Anyway, once a student was holding one and it suddenly performed the defense mentioned in the video, explosively ejecting its guts and gut contents and an amazing amount of mucus all over the student. Incredibly funny.
You can certainly see its relation to the sea cucumber, with its feathery feeding tentacles at one end. (Which end, I’m not entirely sure).