Pseudioninae Codreanu, 1967

Williams, Jason D., Boyko, Christopher B. & Madad, Asma Z., 2019, Branchial parasitic isopods (Crustacea: Isopoda: Bopyridae: Pseudioninae) of hermit crabs (Crustacea: Decapoda: Diogenidae) from the western Pacific, with descriptions of a new genus and three new species, Raffles Bulletin of Zoology 67, pp. 83-118 : 85

Key to genera of Pseudioninae Codreanu, 1967 , with species infesting hermit crabs

1. Females with rudimentary oostegites on pereomeres VI and VII......................... Pagurocryptella Boyko & Williams, 2010

– Females lacking rudimentary oostegites on pereomeres VI and VII............................................................................................2

2. Females usually greatly distorted, typically 90° or more (if not distorted then with propodal sockets on pereopods)..............3

– Females less distorted (generally <70°) or nearly symmetrical, lacking propodal sockets on pereopods..................................5

3. Females with some biramous pleopods..................................4

– Females with no biramous pleopods ........................................ ............................................... Bopyrophryxus Codreanu, 1965

4. Females with propodal sockets on pereopods, first two pereopods much larger than the others ...................................................... .................. Asymmetrione Codreanu, Codreanu & Pike, 1965

– Females without propodal sockets on pereopods, pereopods subequal in size ......................................................................... ......................... Parasymmetrione An, Markham & Yu, 2010

5. Females with biramous uropods .............................................6

– Females with uniramous uropods or lacking uropods ...........7

6. Females with 6 pairs of pleonal lateral plates.......................... .............................................................. Pagurion Shiino, 1933

– Females with 5 pairs of pleonal lateral plates.......................... ...................................................... Parapagurion Shiino, 1933

7. Females with pleomere 6 ventrally displaced, not visible in dorsal view ..............................................................................8

– Females with pleomere 6 not ventrally displaced, visible in dorsal view ..............................................................................9

8. Males with uniramous pleopods ............................................... .................... Bopyrissa Nierstrasz & Brender à Brandis, 1931

– Males with biramous pleopods ..... Propseudione Shiino, 1933

9. Females with pleopod 5 uniramous......................................10

– Females with pleopod 5 biramous...... Eremitione , new genus

10. F e m a l e s w i t h p l e o p o d s 1 a n d 2 b i r a m o u s, 3 a n d 4 uniramous ....................................... Pseudionella Shiino, 1949

– Females with pleopods 1–4 biramous ...................................... ........... Parapseudione Nierstrasz & Brender à Brandis, 1931