Eyes present
Accessory flagellum on antenna 1 present
Urosome I and II without dorsal tubercles
Basipodite of peraeopod V same width as peraeopod IV (the basis of the last two legs).
Dorsal surface of urosome segments armed with a group of spines.
Uropod III: inner ramus 40-100 % of the length of the outer ramus
Genus Gammarus |
The number of Gammarus specimens found outnumber all other species.