Bathyporeia, Lindstrom, 1855

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 : 2763-2766

Bathyporeia cheIJreuxi sp. nov.

( Figures 1–4 ) Bathyporeia pelagica ; Chevreux 1925, p 295, in part, list, no description; Chevreux and Fage 1925, p 94, in part, Dakar record only [not B. pelagica ( Bate, 1857) ].

Etymology

The species is dedicated to Édouard Chevreux who collected the type series more than 100 years ago. The name is a genitive.

Material examined

Holotype: ovigerous female mounted on 10 slides, Melita Sta. 335, Senegal, ‘‘rade de Dakar’’, mud, 5 m depth, 3 March 1890, previously identified as B. pelagica Bate by E. Chevreux, MNHN-Am 5451. Paratypes: 40 specimens, Melita Sta. 333, Senegal, Dakar, 9 m depth, fine sand, 26 February 1890, previously identified as B. pelagica Bate by E. Chevreux, MNHN-Am 5454; two adult males, seven immature males, three ovigerous females, three juveniles, Melita Sta. 335, Senegal, ‘‘rade de Dakar’’, mud, 5 m depth, 3 March 1890, previously identified as B. pelagica Bate by E. Chevreux, MNHN-Am 5452; one immature male, two adult females, Melita, Sta. 337, Senegal, ‘‘rade de Dakar’’, mud, 5 m, 5 March 1890, previously identified as B. pelagica Bate by E. Chevreux, MNHN-Am 5453.

Diagnosis

Pseudorostrum weakly protruding, barely overhanging, upper distal angle regularly rounded, not angular. Pseudorostrum with two to four proximoventral long plumose setae. Flagellum of A1 with six articles in females. Flagellum of A2 with 8–10 articles in females. Coxa 1 with five to seven marginal setae, coxa 2 with 15–24 marginal setae, coxa 3 with 11–16 marginal setae, coxa 4 with 19–29 marginal setae in females. P3–P4 with long dactyli. Carpal fang of P3 reaching 0.78–0.84 of propodus (note: this is the level reached by the carpal fang and not the ratio length of carpal fang/length of propodus). Dactylus of P3 0.46–0.51 (sometimes 0.39) times as long as propodus. Carpal fang of P4 reaching 0.71– 0.74 (sometimes 0.88) of propodus. Dactylus of P4 0.46–0.53 times as long as propodus. Merus of P 5 in female holotype 1.6 times as long as wide. Posterior border of basis of P7 with rather short spines/setae; those of the middle of the border spiniform and distinctly shorter than the proximal and distal ones. Ischium of P7 slightly shorter than in B. tenuipes . Proximal spines of outer side of dorsal border of peduncle of U1 narrow and moderately long; difference between proximal and distal spines small, not clear-cut (rather gradual change between proximal and distal spines). Total number of spines on outer side of dorsal border of peduncle of U1: 8–11 in adults.

Size. 4.5 mm.

Ecology. Fine sand and mud between 5 and 9 m.

Distribution. Senegal.

Discussion

Chevreux presumably took great care to fix the specimens properly since there are no distortion artefacts on the pseudorostrum. A few Bathyporeia from Western Sahara and Mauritania examined are presumably also referable to B. cheυreuxi sp. nov. However they exhibit a higher variability than the type series. They are dealt with elsewhere by d’Udekem d’Acoz et al. (forthcoming) .

Figures

Figure 1. Bathyporeia cheυreuxi sp. nov. Senegal, Dakar: (A, D–J) Melita Sta. 335, female holotype; (B) Melita Sta. 335, female paratype; (C) Melita Sta. 337, female paratype. (A) Right A1; (B) proximal part of left A1; (C) proximal part of right A1; (D) left A2; (E) left Md; (F) right Mxp; (G) right coxa 1; (H) right coxa 2; (I) left coxa 3; (J) right coxa 4. Scale bar: 0.21 mm (A–C, E, H, I); 0.42 mm (D); 0.125 mm (F); 0.175 mm (G); 0.30 mm (J).

Figure 2. Bathyporeia cheυreuxi sp. nov. Senegal, Dakar: (A–H) Melita Sta. 335; (I) Melita Sta. 333. (A–G) Female holotype; (H, I) female paratypes. (A) Anterior part of left P3 (medial spines/setae of propodus not shown); (B) anterior part of right P4 (medial spines/setae of propodus not shown); (C) left P5; (D) left P6; (E) right P7; (F, H, I) posterior border of basis of left P7; (G) ischium of left P7 (medial view). Scale bar: 0.13 mm (A, B); 0.42 mm (C–E); 0.21 mm (F, H, I); 0.20 mm (G).

Figure 3. Bathyporeia cheυreuxi sp. nov. Senegal, Dakar, Melita Sta. 335: (A–C, E–H) female holotype; (D) male paratype; (I) sex unknown (detached appendix), paratype. (A) Right Ep1; (B) left Ep2; (C, D) right Ep3; (E) dorsal part of first urosomite (left side); (F) ventral part of first urosomite and peduncle of right U1 in outer view (medial spines not shown); (G) left U1; (H) left U2; (I) right U3. Scale bar: 0.26 mm (A–D); 0.21 mm (E–H); 0.30 mm (I).

Figure 4. Bathyporeia cheυreuxi sp. nov. Senegal, Dakar, paratypes: (A–F, H) Melita Sta. 335; (G) Melita Sta. 337. (A–D, F) Adult male; (E, G) adult females; (H) sex unknown (incomplete animal). (A) Head, antennae and mandibular palp; (B) second antenna; (C) distal part of right P5; (D) urosomite 1; (E, F) ventral part of first urosomite and peduncle of left U1 in outer view (medial spines not shown); (G, H) ventral part of first urosomite and peduncle of right U1 in outer view (medial spines not shown). Scale bar: 0.42 mm (A); 0.88 mm (B); 0.30 mm (C); 0.26 mm (D); 0.21 mm (E–H).