Idotea linearis

Idotea linearis is a species of elongated isopod crustacean, notable for its narrow body that can be up to seven times longer than it is wide. Males are generally larger than females, reaching lengths of up to 40 millimeters. This species is found from the North Sea down to Morocco and the Mediterranean Sea, inhabiting regions below the littoral zone. Divers may encounter these isopods swimming near sandy shores, especially at low tide. The habitat of Idotea linearis is primarily benthic and temperate, with a distribution that includes the Northeast Atlantic, particularly around France and Germany. Most occurrences of this species are recorded at depths shallower than 40 meters, with a significant number found at depths less than 20 meters. The species is not currently evaluated by the IUCN, CITES, or CMS for conservation status. In terms of reproduction, Idotea linearis is gonochoric, meaning individuals are distinctly male or female. Mating typically occurs before or during the parturial molt, with indirect sperm transfer. Eggs are brooded in a marsupium, and hatch into manca postlarvae before maturing into adults. Divers observing these isopods may notice their active swimming behavior in shallow waters.