Sunday sea cucumber
Two seapigs (holothurians) trundling about in the abyssal depths .
Sea cucumbers are close relatives of sea urchins. Like all echinoderms, cukes are deuterostomes, and have close affinities with chordates. Superficially they have a cylindrical body, a plan also shared with, among others, snakes, worms, slugs, caecilians, eels, and some insect larva. Marine worms of the class Polychaeta are in many ways equally as interesting, but there is something about sea cucumbers, aka Holothurians, that is almost endearing. This (third) picture was taken by Jon Kenfield some time before 1980, with a caption that reads "a sea cucumber from the Red Sea". Cukes like this can grow large- over one meter and nearly five kilograms. The diversity of holothurians also includes deep sea dwelling species (first two pictures) and small species. They are eaten as a delicacy in many countries (namako in Japan, for example).