Nudibranchs

Nudibranchs (NEW-dih-bronks) come in a variety of different shapes and sizes. They can be thick and flat, or long and short. Some are brightly colored, while others are dull. Nudibranchs range in size from 0.25 to 12 in (6 mm to 31 cm) and can weigh up to 3.3 lbs (1.5 kg)

 

These shell-less mollusks, members of the sea slug family, are adorned by some of the most interesting shapes, colors, and patterns. Nudibranchs get their coloring from the food they eat, which helps in camouflage.

 

Nudibranchia, their scientific name, means "naked gills." This vibrant Tritonia species has feathery gills and horns on its back.

 

Nudibranchs cannot see well, but they smell, taste, and feel their surroundings with two highly sensitive tentacles, called rhinophores, located on top of their heads.

 

The digestive gland of the Phyllodesmium iriomotense (pictured above) is located in the tentacle-like growths on its body. It’s very rare for a nudibranch to be colorless.

 

There are more than 3,000 known nudibranch species. They are found throughout the word's oceans, from sandy shallows and reefs to the deep, murky seabed. New species are being identified almost daily.

The bright color of nudibranchs, also called "nudis," warns predators to stay away.