- Norwegian: nakensnegler
The name Nudibranch origin from the Latin "nudus" (naked) and the Greek word for gills, brankia. "Naked gills" is a very descriptive name for these animals. They have no shells, in contrast to many other mollusks. They are bottom-dwelling animals and many species have a very specialized diet which often limits the habitat very you can expect to find them.
Mature nudibranchs are hermaphrodites. This means that each individual has both male and female reproduction organs. After mating, both animals carry fertilized eggs. The eggs are often white or in other bright colors, and laid in characteristic patterns, often a spiral. Most species have a twelve month life cycle.
The nudibranchs along the coast of Norway may be organized in four groups:
- The Aeloids (Aeolidida) have often colorful cerata and long, slender bodies.
- The Dendronotids (Dendronotida) have slender bodies, like the Aeloids.
- The Arminids (Euarminida) are a very diverse order of Nudibranchs. The body is often flattened and the gills are covered by a mantle running along the entire body.
- The Dorids (Doridacea) come in a wide range of shapes and colors.