Arenopontiidae (Sak, 2008)

Sak, Serdar, Karaytuğ, Süphan & Huys, Rony, 2024, Review of Neoleptastacus Nicholls, 1945 (Harpacticoida, Arenopontiidae), including an updated key to species and proposal of Phreatipontia gen. nov., Zootaxa 5525 (1), pp. 1-66 : 61

Key to genera of Arenopontiidae

1. P1 endopod prehensile, enp-1 distinctly longer than exopod; innermost element of P1 exp-3 penicillate.................................................................................................. Arenopontia Kunz, 1937 .

P1 endopod not prehensile, enp-1 not longer than exopod; innermost element of P1 exp-3 geniculate...................2.

2. P5 of both sexes with innermost element forming a distinct spinous process which is incorporated in the segment.........3.

P5 of both sexes with innermost element not modified (occasionally fused at base).................................7.

3. Distal margin of P1 enp-2 with two geniculate setae........................................ Phreatipontia gen. nov.

Distal margin of P1 enp-2 with outer naked spine and inner geniculate seta............ Neoleptastacus Nicholls, 1945 .......4.

4. Anal somite with paired spinous processes either side of anal operculum............................. acanthus -group.

Anal somite without paired spinous processes either side of anal operculum.......................................5.

5. P1 exp-1 without outer spine; distal segment of P1 exopod with three elements; P2 endopod 1-segmented... trisetosus -group.

P1 exp-1 with outer spine; distal segment of P1 exopod with four elements; P2 endopod 2-segmented..................6.

6. Distal segment of P3 endopod with one apical element............................................ australis -group.

Distal segment of P3 endopod with two apical elements....................................... spinicaudatus -group.

7. P1 enp-2 with one geniculate seta and one spine; P3 endopod not modified in ♂ .. Mesopontia Sak, Huys & Karaytuğ, 2008 .

P1 enp-2 with two geniculate setae; P3 endopod sexually dimorphic.............................................8.

8. P2 enp-2 with inner serrate seta; P3 endopod ♂ two-segmented...................... Psammoleptastacus Pennak, 1942 .

P2 enp-2 without inner serrate seta; P3 endopod ♂ one-segmented............ Onychopontia Sak, Huys & Karaytuğ, 2008 .