Bathyporeia cunctator, 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 : 2767-2772

Bathyporeia cunctator sp. nov.

( Figures 5–8 ) Bathyporeia gracilis ; Barnard 1951, p 704; Day 1959, p 528 [non Bathyporeia gracilis G. O. Sars, 1891 ]. Bathyporeia sp. Griffiths 1974a, p 192; 1974b, p 293; 1975, p 135; 1976, p 46, Figure 26b. ‘‘species … close to tenuipes ’’; Vader 1970, p 161.

Etymology

From the Latin cunctator , delayer. The name alludes to the fact that the species was recognized as new by Vader (1970) but only described 35 years later. The name is used as a noun in apposition.

Material examined

Holotype: female (dissected and mounted on 13 slides), University of Cape Town, Ecological Survey, LB. 189. F., South Africa, Langebaan, mid-channel off Skrywershoek, 26 April 1949, previously identified as Bathyporeia gracilis by K. H. Barnard (1951); Day (1959) indicates that it is in Saldanha Bay, 33 ° S, 018 ° E and that the substrate is sandy, SAM A45255. Paratypes: 27 specimens, University of Cape Town, Ecological Survey, LB. 189. F., Langebaan, mid-channel off Skrywershoek, 26 April 1949, SAM A45255; one female, University of Cape Town, Ecological Survey, FBY. 46. U., 34 ° 169S, 018 ° 389E, 59 m, green sand and shell, grab, 25 April 1967, SAM A45256; one fine female, University of Cape Town, Ecological Survey, FBY. 80. E., 34 ° 219S, 018 ° 419E, 82 m, green mud with smell of H 2 S, grab, 13 July 1967, SAM A45257 ; one female, University of Cape Town, Ecological Survey, SB 223 N, 33 ° 00.59S, 017 ° 57.59E, 3 fms (5.5 m), fine khaki sand and stone, rock dredge, 2 May 1960, SAM A45258; one male in pre-terminal intermoult, University of Cape Town, Ecological Survey, SB 242 Q, 33 ° 03.69S, 017 ° 55.59E, 44 m, khaki sand, Van Veen grab, 5 May 1960, SAM A45259 ; 12 females (including very fine ones), University of Cape Town, Ecological Study, FAL 399 X, 34 ° 08.89S, 018 ° 33.59E, 32 m, fine khaki sand, Van Veen grab, 16 May 1961, SAM A45260 ; two females, University of Cape Town, Ecological Survey, FAL 409 J, 34 ° 08.89S, 018 ° 33.59E, 32 m, fine khaki sand, Van Veen grab, 16 May 1961, SAM A45261 ; seven specimens, University of Cape Town, Ecological Survey, FAL 410 X, 34 ° 08.89S, 018 ° 33.59E, 32 m, fine khaki sand, Van Veen grab, 16 May 1961, SAM A45262; one immature male, University of Cape Town, Ecological Survey, FAL 426 T, 34 ° 08.89S, 018 ° 33.59E, 32 m, fine khaki sand, dredge, 16 May 1961, SAM A45263 ; one immature male and eight females, University of Cape Town, Ecological Survey, WCD 37 Y, 33 ° 06.79S, 017 ° 54.89E, 68 m, khaki sandy mud, Van Veen grab, 2 May 1960, SAM A45264; one male in pre-terminal intermoult and two females, University of Cape Town, Ecological Survey, WCD 45 N, 33 ° 06.49S, 017 ° 52.69E, 61 m, khaki sand, rock dredge, 3 May 1960, SAM A45265 ; one large and fine female, University of Cape Town, Ecological Survey, WCD 48K, 33 ° 06.89S, 017 ° 57.19E, 33 m, light grey sand, Van Veen grab, 3 May 1960, SAM A45266; one immature male and two females, University of Cape Town, Ecological Survey, WCD 50 Q, 33 ° 05.59S, 017 ° 53.59E, 78 m, dark green mud, Van Veen grab, 5 May 1960, SAM A45267; one female, University of Cape Town, Ecological Survey, WCD 42 T, 33 ° 06.49S, 017 ° 52.69E, 61 m, khaki sand, Van Veen grab, 3 May 1960, SAM A45268; one very fine female, University of Cape Town, Ecological Survey, SCD 199, 34 ° 109S, 023 ° 329E, 97 m, greenish mud, Van Veen grab, 30 November 1960, SAM A45269; one immature male, University of Cape Town, Ecological Survey, coordinates lost, SAM A45270; one adult male, two immature males and 13 females, University of Cape Town, Ecological Survey, LB. 189. F., Langebaan, mid-channel off Skrywershoek, 26 April 1949, SAM A 18 868.

Diagnosis

Pseudorostrum moderately to extremely protuberant, distinctly to strongly overhanging, upper distal angle regularly rounded, not angular. Pseudorostrum with three to five proximoventral long plumose setae. Flagellum of A1 with six (sometimes five) articles in females. Flagellum of A2 with seven to eight articles in females. Coxa 1 with about nine marginal setae, coxa 2 with 21–40 marginal setae, coxa 3 with 16–30 marginal setae, coxa 4 with 24–70 marginal setae (the number of setae increases with size). P3–P4 with long dactyli. Carpal fang of P3 reaching 0.88–0.91 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 0.40–0.59 times as long as propodus (a single specimen with ratio50.36). Carpal fang of P3 reaching 0.86–0.92 of propodus. Dactylus of P4 0.40–0.57 times as long as propodus. Merus of P 5 in female holotype 1.8 times as long as wide. Posterior border of basis of P7 with rather long spines/setae. Ischium of P7 slightly shorter than in B. tenuipes . Proximal spines of outer side of dorsal border of peduncle of U1 narrow and very long; difference between proximal and distal spines important, clear-cut (change between proximal and distal spines abrupt). Total number of spines on outer side of dorsal border of peduncle of U1: seven to nine (12) in adults.

Size. 4.5 mm.

Ecology. On sandy mud and shell, mud and shell, mud and sand ( Griffiths 1974a, 1974b as Bathyporeia sp.), on sand and shell, on sand, on mud, between 5.5 and 97 m (present study).

Distribution. Lüderitz Bay ( Griffiths 1974a as Bathyporeia sp.), Saldanha Bay ( Day 1959 as Bathyporeia gracilis ), south coast of South Africa ( Griffiths 1974b as Bathyporeia sp.). The material examined during this study comes from south-western South Africa.

Discussion

This form is exceedingly close to B. lindstromi but the posterior spines/setae of the basis of P7 are more robust in B. lindstromi than in B. cunctator sp. nov. Furthermore, the distribution range of both forms is discontinuous. Some of the apparent profile of the pseudorostrum illustrated in B. cunctator sp. nov. may result from distortion artefacts.

Remarks

The collections of the South African Museum include a sample of Bathyporeia group tenuipes without locality, registered as SAM A 13 496 and including 22 specimens (four adult males, three immature males and 15 females). These specimens are very large (up to 6 mm) and look exceedingly similar to B. tenuipes (they have an acute to subacute pseudorostrum). Most probably these specimens are true B. tenuipes from north-west Europe received long ago by K. H. Barnard.

Figures

Figure 5. Bathyporeia cunctator sp. nov. South Africa, LB. 189F, female holotype. (A) Anterior part of head; (B) right A1; (C) left A2; (D) third article of peduncle of left A2; (E) right Md; (F) left Md (palp not shown); (G) outer plate of right Mxp; (H) three distal articles of palp of Mxp; (I) left coxa 1; (J) right coxa 2; (K) right coxa 3; (L) right coxa 4. Scale bar: 0.21 mm (A, B, E, F, J, K); 0.42 mm (C); 0.10 mm (D, G, H); 0.14 mm (I); 0.30 mm (L).

Figure 6. Bathyporeia cunctator sp. nov. South Africa, LB. 189F, female holotype. (A) Anterior part of right P3 (medial spines/setae of propodus not shown); (B) anterior part of left P4 (medial spines/setae of propodus not shown); (C) left P5; (D) right P6; (E) left P7; (F) ischium of left P7 (medial view). Scale bar: 0.21 mm (A, B, F); 0.42 mm (C, D, E).

Figure 7. Bathyporeia cunctator sp. nov. South Africa, LB. 189F, female holotype. (A) Left Ep1; (B) left Ep2; (C) left Ep3; (D) urosomite 1 (left side); (E) left U1; (F) left U2; (G) left U3. Scale bar: 0.42 mm (A–C); 0.30 mm (D); 0.21 mm (E–G).

Figure 8. Bathyporeia cunctator sp. nov. South Africa, paratypes: (A–C, F, H–L) LB. 189F; (D, E, G) FAL 399X. (A–E, H–L) Females; (F, G) adult male. (A–E) Proximal part of left A1; (F) right A2 (spines and setae of peduncle not shown); (G, H) posterior border of basis of right P7; (I–L) ventral part of first urosomite and peduncle of right U1 in outer view (medial spines not shown). Scale bar: 0.21 mm (A–E, G–L); 0.88 mm (F).