Photis guerrai sp. nov. is added to the Atlantic species key of the genus Photis elaborated by Myers (2012)

1 Eyes present.........................................................................................2

- Eyes absent........................................................................ Photis guerrai sp. nov.

2 Antenna 1 longer than half body length....................................................................3

- Antenna 1 not exceeding half body length..................................................................4

3 Male gnathopod 2 propodus palm excavate............................ Photis longicaudata Bate and Westwood, 1862

- Male gnathopod 2 propodus palm rounded.......................................... Photis inornatus Myers, 2012

4 Male coxa 1 narrowing distally, coxa 2 clearly shorter than coxa 3.......................... Photis pollex Walker, 1895

- Male coxa 1 not narrowing distally, coxa 2 not clearly shorter than coxa 3........................................ 5

5 Uropod 3 peduncle longer than rami............................................... Photis reinhardi Kroyer, 1842

- Uropod 3 peduncle subequal or shorter than rami..................................... Photis tenuicornis Sars, 1883