Generally very similar to Ampelisca tenuicornis. Urosome segment 1 with a small rounded dorsal keel, more pronounced in male than in female. Epimeral plate 3 with the posterodistal margin broadly rounded. Head narrowly truncated, ventral margin about straight. Antenna 1 short, in female reaching just beyond the end of the peduncle of antenna 2, peduncle article 1 robust and equal in length to article 2, flagellum up to about l5-articulate. Female antenna 2 about three-quarters of the body length; in male longer than the body. Pereiopod 3 merus without a distal lobe; pereiopods 3 and 4 dactylus about straight and much longer than the carpus and propodus together. Pereiopod 7 basis equal to, or a little longer than the length of the rest of the appendage, ischium longer than the merus, propodus narrowly oval. Uropods 1 and 2 with small marginal spines. Telson elongate, deeply cleft, without dorsal setae and with two to four small apical setules.
Up to 10 mm.
Whitish, yellow-brown laterally with red markings on the margins of the pleon and pereiopods.
Depth range from 10 to 200 metres, usually on sandy or muddy sediments; often found with Ampelisca tenuicornis.
North-East Atlantic, from west Norway to North Africa; Mediterranean, Adriatic, Black Sea.