Aoridae Stebbing 1899
Creators: name: Ariyama, Hiroyuki
name: Kodama, Masafumi
Publisher: name: Zenodo
Year: 2024
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Malacostraca
Amphipoda
Aoridae

description: Key to all species of the family Aoridae in Japan (adult males)
Thirty-four aorid species have been recorded from Japan including the present study. This number suggests a high diversity of the aorid amphipods in Japan, next to Australia with 47 species and 2 subspecies (Lowry & Stoddart 2003). A key to all the Japanese species is shown below. Incidentally, Lembos clavatus Hirayama, 1984 was transferred to the genus Ledoyerella Myers, 1973 in the family Kamakidae Myers & Lowry, 2003 (Ariyama & Mori 2023).
1. Gnathopod 1 carpochelate, uropod 3 uniramous............................................................. 2
- Gnathopod 1 not carpochelate, uropod 3 biramous.......................................................... 17
2. Gnathopod 2 simple; telson short, with dorsal swellings...................................... (Paragrandidierella) 3
- Gnathopod 2 subchelate; telson large, without dorsal swellings................................... (Grandidierella) 5
3. Posterodistal corner of peduncular article 5 of antenna 2 inflated............... Paragrandidierella minima Ariyama, 2002
- Posterodistal corner of peduncular article 5 of antenna 2 not inflated............................................. 4
4. Tooth on gnathopod 1 carpus large (> 0.5 times as long as carpus proper).................. P. urauchiensis Ariyama, 2013
- Tooth on gnathopod 1 carpus small (<0.2 times as long as carpus proper)...................... P. unidentata (Ren, 2006)
5. Gnathopod 2 with dense plumose setae, merus divergent posteriorly.................. Grandidierella gilesi Chilton, 1921
- Gnathopod 2 without plumose setae, merus not divergent...................................................... 6
6. Gnathopod 1 carpus with stridulating ridges................................................................ 7
- Gnathopod 1 carpus lacking stridulating ridges.............................................................. 9
7. Gnathopod 2 carpus shorter than propodus, pereopod 3 basis very slender (length: ca. 5 times of width)....................................................................................... G. gracilis Ariyama & Kohtsuka, 2022
- Gnathopod 2 carpus longer than propodus, pereopod 3 basis not so slender (length: <4 times of width)................. 8
8. Size large (maximum BL: 9.0 mm), coxa 2 lacking posteromedial projection............... G. japonica Stephensen, 1938
- Size small (maximum BL: 5.3 mm), coxa 2 with posteromedial projection................ G. japonicoides Ariyama, 2020
9. Uropod 1 peduncle with inter-ramal process............................................................... 10
- Uropod 1 peduncle without inter-ramal process............................................................. 11
10. Gnathopod 1 ischium with small posterodistal projection................................ G. osakaensis Ariyama, 1996
- Gnathopod 1 ischium lacking posterodistal projection............................. G. pseudosakaensis Ariyama, 2020
11. Gnathopod 1 merus with posterodistal projection, carpus with 3 teeth on posterodistal margin........................ 12
- Gnathopod 1 merus lacking posterodistal projection......................................................... 14
12. Proximal tooth on gnathopod 1 carpus very close to middle tooth.......................... G. contigua Ariyama, 2020
- Proximal tooth on gnathopod 1 carpus apart from middle tooth................................................ 13
13. Both middle and proximal teeth on carpus large......................................... G. fasciata Ariyama, 1996
- Only middle tooth on carpus large.......................................... G. sanrikuensis Ariyama & Taru, 2017
14. Gnathopod 1 carpus with 3 teeth on posterodistal margin (only middle tooth large), coxa 2 with posteromedial projection......................................................... G. halophila Wongkamhaeng, Pholpunthin & Azman, 2012
- Gnathopod 1 carpus with 2 teeth on posterodistal margin, coxa 2 without posteromedial projection.................... 15
15. Gnathopod 1 carpus wide (length: ca. 1.2 times of width).................................... G. nana Ariyama, 2020
- Gnathopod 1 carpus narrow (length: ca. 1.5 times of width)................................................... 16
16. Eyes small (diameter: ca. 0.2 times of head length), teeth on gnathopod 1 carpus close each other.......................................................................................... G. rubroantennata Ariyama & Taru, 2017
- Eyes large (diameter: ca. 0.35 times of head length), teeth on gnathopod 1 carpus separated each other................................................................................... G. ogasawarensis Ariyama & Kawabe, 2022
17. Gnathopod 1 merochelate.............................................................................. 18
- Gnathopod 1 subchelate............................................................................... 30
18. Accessory flagellum developed................................................................... (Aora) 19
- Accessory flagellum vestigial.................................................................. (Aoroides) 20
19. Accessory flagellum with 4 articles, basis of gnathopod 1 with anterior process......... Aora pseudotypica Hirayama, 1984
- Accessory flagellum with 2 articles, basis of gnathopod 1 without anterior process..................................................................................................... A. biarticulata Ariyama & Kohtsuka, 2022
20. Lateral margin of gnathopod 1 basis with many long setae (ca. 20–60).......................................... 21
- Lateral margin of gnathopod 1 basis with sparse short setae (≤ 10)............................................. 26
21. Anteromedial margin of gnathopod 1 carpus heavily setose (ca. 50–80 setae)..................................... 22
- Anteromedial margin of gnathopod 1 carpus with <5 setae................................................... 25
22. Anteroventral corner of coxa 1 with several plumose setae.................................................... 23
- Anteroventral corner of coxa 1 lacking plumose setae....................................................... 24
23. Eyes small (diameter: less than 0.3 times of head length), gnathopod 1 carpus long (length/BL: 0.19–0.21).................................................................................. Aoroides longimerus Ren & Zheng, 1996
- Eyes large (diameter: ca. 0.35 times of head length), gnathopod 1 carpus short (length/BL: 0.13–0.16)........................................................................................ A. macropus Ariyama & Kawabe, 2022
24. Pereopods 3, 4 bearing dense plumose setae, outer and inner rami of uropod 3 without marginal robust setae........................................................................................... A. secundus Gurjanova, 1938
- Pereopods 3, 4 without plumose setae, outer and inner rami of uropod 3 with 0–1 and 1–2 marginal robust setae, respectively........................................................................... A. myojinensis Ariyama, 2004b
25. Anterior margin of gnathopod 1 basis bearing ca. 20 plumose setae, pereopod 7 basis elliptical...................................................................................................... A. ellipticus Ariyama, 2004b
- Anterior margin of gnathopod 1 basis with <10 simple setae, pereopod 7 basis slender....... A. punctatus Ariyama, 2004b
26. Gnathopod 2 propodus curved posteriorly................................................................. 27
- Gnathopod 2 propodus straight......................................................................... 28
27. Outer and inner rami of uropod 3 with 1–2 and 2–3 marginal robust setae, respectively......... A. curvipes Ariyama, 2004b
- Uropod 3 outer ramus marginally bare, inner ramus with 1–2 marginal robust setae........ A. semicurvatus Ariyama, 2004b
28. Posterior margin of gnathopod 1 carpus scarcely setose (<5 setae)....................... A. columnaris Ariyama, 2004b
- Posterior margin of gnathopod 1 carpus with many plumose setae (ca. 15–40).................................... 29
29. Outer and inner rami of uropods 1, 2 each with 6–10 marginal robust setae................... A. rubellus Ariyama, 2004b
- Outer and inner rami of uropods 1, 2 each with 1–3 marginal robust setae........ A. sagamiensis Ariyama & Kohtsuka, 2022
30. Gnathopod 1 propodus shorter than 2 times length of carpus, medial surface covered with dense long setae..................................................................................................... (Tethylembos) 31
- Gnathopod 1 propodus longer than 2 times length of carpus, posteromedial surface weakly setose (ca. 20–40 setae)...... 32
31. Anteroventral corner of coxa 1 acutely projected, pereopod 5 basis excavated posterodistally....................................................................................................... Tethylembos cavatus sp. nov.
- Anteroventral corner of coxa 1 slightly projected roundly, pereopod 5 basis not excavated...... T. japonicus Ariyama, 2004a
32. Posterior margin of gnathopod 1 propodus with dense plumose setae (> 100), maxilliped basis with laterodistal flange............................................................................... Protolembos ryukyuensis sp. nov.
- Posterior margin of gnathopod 1 propodus weakly setose (ca. 20–30 setae), maxilliped basis without flange............ 33
33. Posterior margin of gnathopod 1 propodus serrate; gnathopod 2, anterior and posterior margins of carpus–propodus weakly setose with short setae.................................................. Pseudobemlos serratus Ariyama, 2004a
- Posterior margin of gnathopod 1 propodus with long acute tooth; gnathopod 2, anterior and posterior margins of carpus– propodus with dense long setae....................................... Bemlos seisuiae Kodama & Kawamura, 2019
description: Published as part of Ariyama, Hiroyuki & Kodama, Masafumi, 2024, Three species of the family Aoridae Stebbing, 1899 (Crustacea: Amphipoda) collected from remote islands in southern Japan, with a key to all Japanese species of the family, pp. 500-528 in Zootaxa 5433 (4) on pages 524-526, DOI: 10.11646/zootaxa.5433.4.2, http://zenodo.org/record/10954486