Crambe crambe

Crambe crambe, commonly known as the oyster sponge or orange-red encrusting sponge, is a species of demosponges belonging to the family Crambeidae.

Description
The colonies of Crambe crambe form thin orange to orange-red plates, rarely lobed, with a very rough surface perforated by raised oscula found along the exhaling channels. These colonies can cover a surface of 1 m2.

Biology
Crambe crambe feeds by filtering bacteria, microorganisms and single-celled algae. This species is hermaphrodite. Larvae are planktonic. These demosponges often cover the shell of live shellfish (Arca noae, Spondylus and various sedentary bivalves). Eupolymnia nebulosa sometimes hides itself on these sponges.

Distribution
This species is endemic to the Mediterranean, but it is also present in the North Atlantic Ocean, in the English Channel and in the North Sea.

Habitat
Crambe crambe commonly occurs in well-lit waters on hard substrate at depths of 5 to 30 m.