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.
Up to 18 mm.
Greenish brown, quite variable.
Intertidal, usually found amongst decaying weed around high water mark on shingle shores. Locally abundant. May be confused with gammarellus, and often found together.
North East Atlantic; North Sea; Mediterranean; widespread and frequently recorded on European coasts from British Isles to Mediterranean and Black Sea.