Green Wednesday: Nudibranch! (thanks to Maria & Jill for the contribution)

on 20 Feb 2013 
Verco's nudibranch

A nudibranch is a member of Nudibranchia, a group of soft-bodied, marine gastropod mollusks which shed their shell after their larval stage.

They are noted for their often extraordinary colors and striking forms. There are more than 3,000 described species of nudibranchs.

Nudibranchs are often casually called sea slugs, but many sea slugs belong to several taxonomic groups which are not closely related to nudibranchs. A number of these other sea slugs, such as the colorful Aglajidae, are often confused with nudibranchs.

Nudibranchs occur in seas worldwide, including both the tropics and Antarctica.

Nudibranchs live at virtually all depths of salt water, from the intertidal zone to over 700m. Their greatest size and variation is in warm, shallow waters.  Nudibranchs are benthic animals, found crawling over the bottom substrate.  Nudibranchs use a variety of chemical defenses to aid in protection, but it is not necessary for the strategy to be lethal in order to be effective: some successful toxins induce bradycardia or hypotension in a predator, allowing the nudibranch to escape consumption while its attacker is incapacitated

Nudibranchs are hermaphroditic, and thus have a set of reproductive organs for both sexes, but they cannot fertilize themselves.

They typically deposit their eggs within a gelatinous spiral.

Verco's nudibranch