Bathyporeia, D’Acoz & Vader, 2005

D’Acoz, Cédric D’Udekem & Vader, Wim, 2005, New records of West and South African Bathyporeia, with the description of four new species and a key to all species of the genus (Crustacea, Amphipoda), Journal of Natural History 39 (30), pp. 2759-2794 : 2789-2793

Key to the genus Bathyporeia

Specimens of all species have been examined. Bathyporeia sp. which is known from a single mutilated specimen only is not included. Some species appear twice in the key. When examining West or South African material, it must be borne in mind that undescribed species may be expected in these areas. The geographical range of southern species is imperfectly known and the distributional indications given in the key should therefore be considered with caution.

1. Posterodistal seta group of merus of P5 with at least two spines or stout setae. Posterior border of basis of P7 strongly expanded and angular (the angle divides the posterior border in a posteroproximal and a posterodistal part). NW Atlantic 2

– Posterodistal seta group of merus of P5 with one large spine or stout seta and often one or several minute slender setules. Posterior border of basis of P7 not strongly expanded, not angular, not divided in two distinct parts. E Atlantic and Mediterranean.................... 3

2. Basis of P5 broad and elliptic with posterior border strongly convex. Posterior border of basis of P7 strongly angular, with spines on posteroproximal part and setae on posterodistal part. Middle of posterior border of Ep1–Ep2 pointed. Posterior border of Ep3 strongly convex considerably overreaching posteroventral tooth. Urosomite 1 with two (sometimes three) pairs of spinules on the anterior hump. Medial side of outer ramus of U3 with one plumose seta and one long slender spiniform non-setulose seta at the tip of the first article. Telson lobes without medial setae. South of Cape Cod to north Florida................ B. parkeri Bousfield, 1973 – Basis of P5 rather narrow with anterior border nearly straight and posterior border straight, both borders parallel. Posterior border of basis of P7 obtusely angular, with setae and spines on posteroproximal part and on angle separating the two parts; no spines/setae on posterodistal part itself. Middle of posterior border of Ep1–Ep2 barely angular. Posterior border of Ep3 weakly convex, not reaching posteroventral tooth. Urosomite 1 without spinules on the anterior hump (only on the posterior hump). Medial side of outer ramus of U3 with two to three very strong spines and often a plumose seta at the tip of the first article. Telson lobes with one to two pairs of medial setae. Nova Scotia to Chesapeake Bay............... B. quoddyensis Shoemaker, 1949

3. Posterodistal seta group of merus of P5 with a short spiniform seta, shorter than half of carpus length.................. 4

– Posterior seta group of merus of P5 with a long slender seta, longer than half of carpus length.................... 9

4. Coxa 2 with anterior and posterior borders strongly diverging downwards. Carpus of P6 with at least one group of spines on posterior border (besides distal group). Ventrolateral border of urosomite 1 with spiniform setae. Outer dorsal border of peduncle of U1 proximally with long or fairly long setae: B. tenuipes complex. 5

– Coxa 2 with anterior and posterior borders not diverging downwards. Carpus of P6 without groups of spines on posterior border (besides distal group). Ventrolateral border of urosomite 1 without spiniform setae. Outer dorsal border of peduncle of U1 proximally (and distally) with short spines...... 8

5. Proximal dorsal setae of outer border of peduncle of U1 extremely long; difference between proximal and distal setae important, clear-cut........ 6

– Proximal dorsal setae of outer border of peduncle of U1 moderately long; difference between proximal and distal setae slight, not clear-cut [pseudorostrum rounded not very protruding; dactylus of P3–P4 usually.0.45 times as long as propodus; middle of posterior border of basis of P7 with spines]. Senegal.................. B. cheυreuxi sp. nov.

6. Dactylus of P3–P4 usually.0.45 times as long as propodus. Pseudorostrum rounded to subangular................. 7

– Dactylus of P3–P4 usually,0.45 times as long as propodus. Pseudorostrum usually sharply angular, sometimes subangular. [Middle of posterior border of basis of P7 with setae]. NW Europe...... B. tenuipes Meinert, 1877

7. Pseudorostrum rounded to subangular. Middle of posterior border of basis of P7 with spines. Mediterranean........ B. lindstromi Stebbing, 1906

– Pseudorostrum rounded. Middle of posterior border of basis of P7 with setae. S Africa................ B. cunctator sp. nov.

8. Coxa 1 with tooth. Carpal fang of P3–P4 entire. Unguis of P3–P4 well developed. Border of inner ramus of U1–U2 facing outer ramus with at least two long spines. Medial border of U3 without accessory spiniform setae (except often a small one associated to the most distal plumose seta of the first article). NW Europe, temperate N Africa, Mediterranean, Black Sea. Extreme lower shore and subtidal......... adult males of B. guilliamsoniana ( Bate, 1857)

– Coxa 1 without tooth. Carpal fang of P3–P4 with two narrow apical branches. Unguis of P3–P4 very short. Border of inner ramus of U1–U2 facing outer ramus with one long spine. Medial border of U3 with several well-developed accessory spiniform setae. NW Europe, south to N Portugal. Mostly on the middle of the shore and higher, usually uncommon below tidemarks............. adult males of B. pelagica ( Bate, 1857)

9. Ventrolateral border of urosomite 1 with at least one spiniform seta... 10

– Ventrolateral border of urosomite 1 without spiniform setae..... 12

10. Carpus of P6 without groups of spines on posterior border (besides distal group). Urosomite 1 with zero to one pairs of posteriorly directed dorsal spines. Outer dorsal border of peduncle of U1 proximally (and distally) with short spines. 11

– Carpus of P6 with at least one group of spines on posterior border (besides distal group). Urosomite 1 with two to three pairs of posteriorly directed dorsal spines. Outer dorsal border of peduncle of U1 proximally with setae or long slender spines. NW Europe, rare......... B. gracilis G. O. Sars, 1891

11. A1 of adult male much shorter than body. P3–P4 with stout dactyli, with carpal fang blunt-tipped and with accessory seta. Urosomite 1 without pair of posteriorly directed dorsal spines. U3 with first article very broad and second short. Adults. 3 mm. NW Europe............ B. sarsi Watkin, 1938

– A1 of adult male about as long as body or longer. P3–P4 with slender dactyli, with carpal fang with narrow acute tip and without accessory seta. Urosomite 1 usually with one pair of posteriorly directed dorsal spines (rarely without spines). U3 with first article of normal width and second of normal length. Maximum length, 3 mm. Mediterranean....................... Bathyporeia sp. 1 (d’Udekem d’Acoz and Vader, forthcoming)

12. Carpal fang of P3–P4 bifid or blunt with an accessory seta. Coxa 1 without tooth 13

– Carpal fang of P3–P4 entire and with narrow acute tip. Coxa 1 with or without tooth...................... 19

13. Carpal fang with broad blunt tip and narrow accessory seta. Coxae 2–3 without tooth. Ep3 never with tooth. Urosomite 1 with or without pair of posteriorly directed dorsal spines................. 14

– Carpal fang with two narrow acute branches. Coxae 2–3 with small tooth separated from coxa by shallow notch. Ep3 usually with small tooth. Urosomite 1 with pair of posteriorly directed dorsal spines. [Pseudorostrum very angular]. NW Europe...... females and immature males of B. pelagica ( Bate, 1857)

14. Pseudorostrum of normal proportions. Second article of U3 not simultaneously long and broad. NE Atlantic............... 15

– Pseudorostrum short, very broad in its middle. Second article of U3 long and broad. [A2 of adult males not longer than in females. Dactylus of P3–P4 very stout with short unguis. Urosomite 1 with pair of anteriorly directed setae but without pair of posteriorly directed spines]. S Africa..... B. gladiura sp. nov.

15. Second article of outer ramus of U3 with setae on medial side only. Dactylus of P3–P4 slender or robust, with posterior border straight or convex and with short or fairly short unguis. A2 of adult males longer than in females..... 16

– Second article of outer ramus of U3 with setae on both sides. Dactylus of P3–P4 slender, curved and with long unguis. A2 of adult males not longer than in females. [Urosomite 1 with pair of anteriorly directed setae but without pair of posteriorly directed spines]. N of Morocco and SW of Iberian Peninsula.......... B. elkaimi d’Udekem d’Acoz and Menioui, 2004

16. U3 with first article very broad. [Urosomite 1 with pair of anteriorly directed setae but usually without pair of posteriorly directed spines]. NW Europe only.. 17

– U3 with first article of normal width. Western Sahara....... 18

17. Pseudorostrum apex regularly rounded and very narrow; tip of coxa 1 fairly narrow; subdistal setule of carpal fang about as long as tip of fang; P5 merus posteromedian group of setae consisting of one major glabrous seta and one long very plumose accessory seta; P7 basis with narrow setae on posterior border in females. Not farther south than the Bay of Biscay.. B. pilosa Lindström, 1855

– Pseudorostrum apex subrectangular and always broad in females, more rounded and fairly narrow (i.e. much less characteristic) in males; tip of coxa 1 broadly rounded; subdistal setule of carpal fang much longer than tip of fang; P5 merus posteromedian group of setae consisting of one major glabrous seta and one to two very short setae which are sparsely setulose or appear as non-setulose on microscopical preparations; P7 basis with spines on posterior border in females. As far south as Galicia and possibly N Portugal.... B. sarsi Watkin, 1938

18. Dorsal surface of article 2 of Mxp palp with four to six strong long setae in adults. Coxa 1 anteriorly not especially broad, without ventral angular discontinuity, without very short seta behind the anteroventral long setae. Dactylus of P3–P4 normally developed and fairly slender. Posterior border of basis of P7 straight or slightly concave. Ventrolateral surface of Ep3 with spines forming at least one transverse row. Urosomite 1 with pair of well-developed and stout posteriorly directed dorsal conical spines (besides pair of anteriorly directed setae)............ B. ledoyeri d’Udekem d’Acoz and Menioui, 2004

– Dorsal surface of article 2 of Mxp palp with 13–17 strong long setae in adults. Coxa 1 usually anteriorly very broad, usually with ventral angular discontinuity, with very short seta behind the anteroventral long setae. Dactylus of P3–P4 very short and stout. Posterior border of basis of P7 convex. Ventrolateral surface of Ep3 with spines scattered and not forming transverse rows. Urosomite 1 with at least one pair of short and slender posteriorly directed dorsal setiform spines (besides pair of anteriorly directed setae)................... Bathyporeia sp. 2 (d’Udekem d’Acoz et al., forthcoming)

19. Ep3 with tooth................... 20

– Ep3 without tooth.................. 21

20. Tip of pseudorostrum rather high. Coxa 1 acute with ventral tooth. Basis of P5–P7 with many setae on posterior border. Ep3 with many ventrolateral spines, most spines forming transverse rows. Second article of U3 with several setae on both sides. Up to 7 mm long. NW Europe, temperate N Africa, Mediterranean, Black Sea..... females and immature males of B. guilliamsoniana ( Bate, 1857)

– Tip of pseudorostrum narrow. Coxa 1 blunt without ventral tooth. Basis of P5–P7 with one to three spines/setae on posterior border. Ep3 with one single ventrolateral spine. Second article of U3 with a seta on medial side and none on outer side. About 3 mm long. Western Sahara.........

......... B. microceras d’Udekem d’Acoz and Menioui, 2004

21. Urosomite 1 with at least one pair of posteriorly directed dorsal spines.. 22

– Urosomite 1 without pair of posteriorly directed dorsal spines. [Coxae 1–3 without tooth. Second article of U3 with setae on medial side only.] Mediterranean......... B. phaiophthalma Bellan-Santini, 1973

22. Either coxae 1–3 each with tooth or notch, or none with tooth or notch. Normally one pair of posteriorly directed dorsal spines (when there are two, they are close to each other). European species.............. 23

– Coxae 1 and 3 without tooth or notch; coxa 2 with small tooth or notch. Usually two pairs of dorsal spines separated by long space (sometimes a single spine). [Second article of U3 quite long but with setae on medial side only.] Namibia.................. B. griffithsi sp. nov.

23. Coxae 1–3 with tooth. Coxa 1 without apical setule. Adults normally. 3 mm 24

– Coxae 1–3 without tooth. Coxa 1 with apical setule. Adults normally, 3 mm. NW Europe............... B. nana Toulmond, 1966

24. Second article of U3 with seta(e) (if any) on medial side only. Eggs pink. Norway............ B. elegans Watkin, 1938 forma A

– Second article of U3 may have seta(e) on both sides. Eggs whitish to yellowish. Western Europe and Mediterranean... B. elegans Watkin, 1938 forma B