Nudibranchs A Colorful and Diverse Critter, But What are They?

Nudibranchs are some of the oceans’ most diverse species, and can be found nearly everywhere. once you see a nudibranch, it is almost certain that you will never miss another of these wonderful, diverse species ever again.

With the abundance of life available to observe beneath the surface of the sea, it can be all too easy to overlook the smaller inhabitants of coral reefs and other ocean habitat. But once you see a nudibranch, it is almost certain that you will never miss another of these wonderful, diverse species ever again.

Photo Credit: tarotastic

Nudibranchs what are they?

The nudibranch is often mistaken for a sea slug, with which it shares many similarities, but in fact, many species of sea slugs descend from an entirely different group that are not at all related to nudibranchs.

Nudibranchs form their own taxonomic clade of marine gastropod mollusks, who differ from other mollusks in that they eschew their shells once the larval stage is complete. Known for their bright color and pattern variations, they can be seen in virtually all seas worldwide, although a shallow, warm reef habitat is preferred.

They can vary in size from half an inch to 24 inches, and the protruding tentacles on their heads are sensitive to touch, taste, and smell. The nudibranch has poor eyesight, often only able to discern the difference between light and dark.

Nudibranchs are carnivorous creatures.

Nudis feed on sponges, anemones, barnacles, sea slugs, hydroids (creatures related to jellyfish), and on rare occasions, their own eggs and even other nudibranchs.

Venomous nematocysts from hydroids do not have a lethal or dangerous effect on the nudibranch; instead of digesting the toxins, it passes through their gut to the surface of their skin, to provide a means of defense against predators. Tactics such as this have enabled the nudibranch to evolve beyond the need for the protective shell that is typical of mollusks.

Photo Credit: alfonsator

Colorful Nudibranchs

Their bold colors and unusual patterns lend themselves to further defense of the nudibranch, as many species of fish and birds associate their flashy appearance with other marine creatures that have left a bad taste in their mouths. Surprisingly, the bizarre color and pattern formations can do much to camouflage the nudibranch from predators in the reef.

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This article is published by The Scuba Page, the online magazine for Scuba Dive lovers around the world. The Scuba Page is part of RUSHKULT : the online booking platform for adventure sports. Visit the RUSHKULT platform to book your next Scuba Dive training, guided trip and accommodation.