Key to species of Stenogammarus

1. Uropod 3 reduced, 1st exopod article 1 as long as peduncle ........................................................... S. micrurus

- Uropod 3 not reduced, 1st exopod article longer than peduncle ........................................................................... 2

2. Uropod 3 exopod inner margin bare/with 1 long seta ........................................................................................... 3

- Uropod 3 exopod inner margin with multiple long setae .......................................................................................... 4.

3. Pereopods 6–7 basis medial surface with clusters of setae, basis 6 with long setae on posterior margin, basis 7 with long setae on anterior margin ... S. compresso-similis

- Pereopods 6–7 basis medial surface bare, basis 6 with short setae on posterior margin, basis 7 with short setae on anterior margin .............................................. S. deminutus .

4. Uropod 3 exopod 2nd article shorter than half of 1st article ................................................................... S. similis

- Uropod 3 exopod 2nd article as long/longer than half of 1st article ..................................................................... 5.

5. Uropod 3 endopod longer than 2nd exopod article and is 1/2 of 1st article ........................................ S. compressus

- Uropod 3 endopod shorter than 2nd exopod article and is 1/3 1st article ............................................... S. macrurus