Gad-Zooks Cukes!

Sea Cucumbers, Class Holothuroidea: With body shapes ranging from spherical to long and worm-like, bizarre rings of tentacles circling a non-descript head-end, these slow-moving, drab to brightly colored and marked invertebrates are well-known at least by sight, by most aquarists.

Unfortunately they have a dark side. Like many other spiny-skinned animals, Sea Cucumbers should only be tried in captivity with knowledge, trepidation and utmost vigil. The reasons for my cautioning are offered here, as well as notes on general selection and care for the still curious.

Classification:

Sea Cucumbers make up the Class Holothuroidea of the "Spiny-skinned-animal" phylum Echinodermata. Other living Classes comprise the familiar Sea Urchins, Sand Dollars, Sea- and Brittle Stars and the Crinoids, aka Sea Lilies and Feather Stars. Holothuroids are the odd-Class out in being secondarily non-radial appearing; often looking like strange ornamental sausages, some translucent, others opaque and warty. Cucumber-like! 

There are some 900 described species, almost exclusively marine, distributed worldwide. Sea Cucumbers are a major component of the deep sea fauna. Most are black, brown or olive in color, but many brilliant colored and patterned species are encountered. They range in size to barely over an inch (@ 3 cm.) end to end to over a meter in length.

Genus Actinopyga: "Toothed Sea Cucumbers", named for the series of five teeth ringing their anus.