Costa, 1853
Description:
Epimeral plate 3 posterodistal angle quadrate. Eyes rounded, black in colour. Antenna 1 just reaching end of peduncle article 4 of antenna 2, flagellum about 6-articulate. Antenna 2 up to one-third body length, flagellum equal to length of peduncle, up to about 22-articulate. Antenna 2 less robust in female than male. Male gnathopod 1 carpus and propodus with prominent posterior lobe, dactylus shorter than palm. Female gnathopod 1 carpus and propodus without posteromarginal lobe, dactylus longer than palm. Male gnathopod 2 propodus very large and robust, obpyriform, palm strongly oblique and more than half posterior margin, sinuous, dactylus elongate and curved. Female gnathopod 2 basis broad proximally, anterior margin slightly sinuous, carpus with symmetrical posterior lobe, propodus of mitten-type. Pereopod 7 basis broad; in male carpus and propodus more or less expanded and may be especially broad in large specimens; in female and small male merus and carpus basic; propodus slender and straight. Pleopods with rami about equal to length of peduncle. Telson fleshy, with several small marginal spines, apex with small notch.
Size:
Up to 18 mm.
Colour:
Greenish brown, quite variable.
Habitat:
Intertidal, usually found amongst decaying weed around high water mark on shingle shores. Locally abundant. May be confused with gammarellus, and often found together.
Distribution:
North East Atlantic; North Sea; Mediterranean; widespread and frequently recorded on European coasts from British Isles to Mediterranean and Black Sea.