''Jassa marmorata'' is a species of tube-building amphipod. It is native to the northeast

Atlantic Ocean The Atlantic Ocean is the second-largest of the world's five oceans, with an area of about . It covers approximately 20% of Earth's surface and about 29% of its water surface area. It is known to separate the " Old World" of Africa, Europe ...

but has been introduced into northeast

Asia Asia (, ) is one of the world's most notable geographical regions, which is either considered a continent in its own right or a subcontinent of Eurasia, which shares the continental landmass of Afro-Eurasia with Africa. Asia covers an are ...

. ''J. marmorata'' are greyish in colour with reddish brown markings. The can grow to a length of up to . They are generally found in fouling communities and intertidal areas where they build tubes of detritus and algae fragments using silky mucus secretions. They are remarkable for having two distinct morphs of males with two different mating strategies. The 'major' morphs are fighter males, while the 'minor' morphs are sneaker males. ''J. marmorata'' is classified under the genus '' Jassa'' of the

family Family (from la, familia) is a group of people related either by consanguinity (by recognized birth) or affinity (by marriage or other relationship). The purpose of the family is to maintain the well-being of its members and of society. Idea ...

Ischyroceridae Ischyroceridae is a family of amphipods. It contains the following genera: *'' Ambicholestes'' Just, 1998 *'' Bonnierella'' Chevreux, 1900 *'' Cerapus'' Say, 1817 *'' Ericthonius'' Milne-Edwards, 1830 *'' Ischyrocerus'' Krøyer, 1838 *''Jassa ...

. They are commonly confused with the closely related scud ('' Jassa falcata'').

References

Corophiidea Crustaceans of the Atlantic Ocean Crustaceans described in 1905 {{Amphipod-stub