Calliopiidae, G. O. Sars, 1893

Wang, Yan-Rong, Zhu, Chao-Dong, Sha, Zhong-Li & Ren, Xian-Qiu, 2020, Bathya brevicarpus gen. et sp. nov. (Amphipoda: Senticaudata: Calliopiidae), from hydrothermal vents, Okinawa Trough, North-west Pacific, European Journal of Taxonomy 693, pp. 1-12 : 8-10

Identification key to genera of the Calliopiidae

Key based on original or amended descriptions of genera and adapted from previous keys given by Barnard (1964), Barnard & Karaman (1991) and Bousfield & Hendrycks (1997). All genera included in this key are according to Lowry & Myers (2013) and WoRMS (2020).

1. Mandibular molar not triturative, usually conical ............................................................................ 2

– Mandibular molar triturative, columnar, rather conical .................................................................... 3

2. Carpus of gnathopods 1–2 shorter than propodus, weakly lobed; antenna 2 elongate ....................... ............................................................................................................... Harpinioides Stebbing, 1888

– Carpus of gnathopods 1–2 as long as propodus, unlobed; antenna 1 elongate ................................... .............................................................................................................. Calliopiurus Bushueva, 1986

3. Inner plate of maxilla 2 much broader than outer plate .................... Pontogeneoides Nicholls, 1938

– Inner plate of maxilla 2 not much broader than outer plate .............................................................. 4

4. Coxae very short and progressively longer towards coxa 7 ............................................................. 5

– Coxae not as greatly shortened and not progressively lengthened towards coxa 7 .......................... 6

5. Carpus and propodus of pereopods 6–7 extremely elongate (planktonic); body carinate; coxa 1 not or scarcely produced anteriorly ........................... Stenopleuroides Birstein & M. Vinogradov, 1964

– Carpus and propodus of pereopods 6–7 not extremely elongate; body smooth; coxa 1 produced anteriorly................................................................................................. Stenopleura Stebbing, 1888

6. Palp of maxilla 1 reduced, not exceeding apex of outer plate, article 1 longer than article 2............. ......................................................................................................................... Laothoes Boeck, 1871

– Palp of maxilla 1 ordinary, article 1 shorter than article 2 ................................................................ 7

7. Rami of uropods 1–2 without marginal robust setae, only with distal robust setae ........................... ........................................................................................................... Calliopiella Schellenberg, 1925

– Rami of uropods 1–2 with both marginal and distal robust setae ..................................................... 8

8. Gnathopods 2 very slender, linear, carpus very slender and elongate, unlobed, propodus generally elongate and linear (except in Amphithopsis ) ................................................................................... 9

– Gnathopod 2 not very slender nor linear nor greatly elongate (propodus not especially elongate) .... ......................................................................................................................................................... 18

9. Gnathopod 1 ordinary, neither linear nor elongate ......................................................................... 10

– Gnathopod 1 linear, elongate .......................................................................................................... 12

10. Propodus of gnathopod 2 not linear; dactylus of pereopods 3–7 serrated .......................................... .................................................................................................................. Amphithopsis Boeck, 1861

– Propodus of gnathopod 2 linear; dactylus of pereopod 3–7 not serrated ........................................11

11. Accessory flagellum absent; lower lip with inner lobe absent .............. Bouvierella Chevreux, 1900

– Accessory flagellum present; lower lip with inner lobe present ................... Oradarea Walker, 1903

12. Dactylus of pereopods 3–7 with one or more superior robust setae ............. Cleippides Boeck, 1871

– Dactylus of pereopods 3–7 without superior robust setae .............................................................. 13

13. Carpus of gnathopods 1–2 much longer than propodus ................................................................. 16

– Carpus of gnathopods 1–2 scarcely longer and usually shorter than propodus .............................. 14

14. Gnathopod 2 much longer than gnathopod 1, carpus and propodus extremely slender like that of pereopod 3–7 ................................................................................... Leptamphopus G.O. Sars, 1893

– Gnathopod 2 as long as or slightly longer than ganthopod 1, carpus and propodus normal .......... 15

15. Telson entire, linguiform .................................................... Membrilopus Barnard & Karaman, 1987

– Telson with shallow apical notch on distal margin .................... Frigora Ren in Ren & Huang, 1991

16. Antennae calceolate; antenna 1, peduncular article 3 with posterodistal process; uropod3, rami margin only with simple setae ....................................................................... Halirages Boeck, 1871

– Antennae usually lacking calceoli; antenna 1, peduncular article 3 unmodified; uropod 3, margins with robust setae and inner marginal setae only ............................................................................. 17

17. Propodus of gnathopods expanded; pereopods 5–7 elongated ........... Haliragoides G.O. Sars, 1893

– Propodus of gnathopods not expanded; pereopods 5–7 normal, not extremely elongated ................ ....................................................................................................................... Apherusa Walker, 1891

18. Peduncular article 3 of antenna 1 produced apicoventrally ............................................................ 19

– Peduncular article 3 of antenna 1 not or weakly produced apicoventrally ..................................... 21

19. Carpus on either of gnathopods 1–2 much shorter than propodus ................................................. 20

– Carpus on either of gnathopods 1–2 scarcely shorter than or longer than propodus .......................... ..................................................................................................................... Lopyastis Thurston, 1974

20. Carpus of gnathopods not lobate ................................................................ Tylosapis Thurston, 1974

– Carpus of gnathopods strongly lobate ..................................................... Calliopius Lilljeborg, 1865

21. Epimeron 3 serrate .......................................................................................................................... 22

– Epimeron 3 smooth ......................................................................................................................... 23

22. Accessory flagellum well developed, 3+ articulate ............................... Weygrechita Stuxberg, 1880

– Accessory flagellum scale-like ............................................................... Oligochinus Barnard, 1969

23. Rostrum small ................................................................................................................................. 24

– Rostrum large .................................................................................................................................. 27

24. Accessory flagellum absent ............................................................................................................ 25

– Accessory flagellum 1-articulate, scale-like ........ Paracalliopiella Tzvetkova & Kudrjaschov, 1975

25. Gnathopod 1 larger in size than gnathopod 2 .................... Whangarusa Barnard & Karaman, 1987

– Gnathopod 1 similar in size to gnathopod 2 ................................................................................... 26

26. Carpus of gnathopods 1–2 much shorter than propodus; outer ramus of uropod 3 ½ length of inner ramus; telson longer than broad, entire .................................................................... Bathya gen. nov.

– Carpus of gnathopods 1–2 subequal to propodus; rami of uropod 3 subequal in length; telson broader than long, emarginated ............................................... Lutriwita Lowry & Myers, 2012 (fresh water)

27. Dactylus of pereopods 3–7 bifid ...................................... Manerogeneia Barnard & Karaman, 1987

– Dactylus of pereopods 3–7 pectinate ......................................... Metaleptamphopus Chevreux, 1911