Not going to win any beauty contests . . .Ateleopus purpurea. Photo by Rodolfo B. Reyes and Fishbase, distributed under a Creative Commons Noncommercial Attribution 3.0 Unported License

Jellynose fish have cartilaginous bones like sharks, though they are in the same group as bony fishes (Teleosts). They seem to have lost their calcified bones secondarily — yet another case of convergent evolution. Cartilage is a living connective tissue that pads your joints. In cartilaginous fishes, the stiff, flexible stuff is all the skeleton they have, with one big exception: the teeth. That’s why most all we have of those giant Megalodon sharks are their rather imposing choppers (in fact, that’s what Megalodon means: mega (huge-***) + odon (tooth)).

As the video says, we know very little about them because they live in the deep sea. Here’s a reasonably good hierachy of the group (see right side of page); here you can see how they fit into the Tree of Life web project (look for Ateleopodomorpha).

What do you think that jelly nose is for, other than grossing out “sensitive viewers”? Anyone?