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 : 2787-2789

Bathyporeia sp.

Material examined.

One adult female in alcohol, Melita Sta. 333, Senegal, Dakar, 9 m depth, fine sand, 26 February 1890, previously identified as B. pelagica Bate by E. Chevreux and previously mixed together with B. cheυreuxi sp. nov. (right appendages lacking, presumably previously dissected), MNHN-Am 5461; one ovigerous female (two dried out slides with right appendages, but without P6 and without U3; microscopical preparations probably made from the specimen in alcohol listed above, which had been partly dissected), Melita Sta. 333, Senegal, Dakar, 9 m depth, fine sand, 26 February 1890, MNHN-Am 5462 .

Description of the specimen in alcohol

Species rather slender. Eye very large with well-developed ommatidia. Pseudorostrum with bluntly subquadrate tip, of normal height, scarcely overhanging, with two proximoventral setae; development and number of apical spines normal. Major flagellum of A1 with six articles; first article of accessory flagellum with two non-apical groups of spines. Anterior border of article 3 of peduncle of A2 with one group of spinules and setae in apical position; article 4 with lateral and apical spinules; flagellum with 10 articles.

Penultimate article of mandibular palp elongate but broader than ultimate article.

Third article of maxilliped palp with longitudinal row of setae on dorsal side.

Coxa 1 with tip narrowly rounded, without ventral tooth, without ventral notch, without anteroventral angular discontinuity, with well-developed ventral setae, without apical setule.

Coxa 2 without posterior tooth but with notch; transition between anterior and ventral border without angular discontinuity; anterior border curved and convex; ventral border with 10 narrow regular-sized setae of normal length (except posterior seta associated with notch, which is reduced to a setule); probably five medial setae (difficult to see without dissection).

Coxa 3 without posterior tooth but with notch; ventral border with 11 regular-sized setae, of normal width and length (except posterior seta associated with notch, which is reduced to a setule); six medial setae.

Coxa 4 with 20 regular-sized setae, of normal width and length; posterior setae not setulose.

P3 with carpal fang just overreaching tip of propodus, distally styliform, without accessory setule; propodus rather slender; outer spines/setae of propodus in normal number (eight), of normal size and shape; dactylus slender, of normal size, with normal-sized unguis (albeit not very long), with posterior border slightly concave (unguis considered or not).

P4 with carpal fang reaching tip of propodus, distally styliform, without accessory setule; propodus of normal robustness; outer spines/setae of propodus in normal number (seven), of normal size and shape; dactylus rather short, difficult to examine properly without dissection.

Median part of anterior border of basis of P5 straight (faintly convex); merus rather narrow; posteromedian seta group of merus with one long seta and no accessory seta; posterodistal seta group with one long and strong straight seta (reaching tip of carpus), and without setule; longest posterior spine of carpus almost overreaching tip of propodus; ratio between carpus+propodus length and merus length in adult female: 0.95.

Posterodistal lobe of basis of P6 protruding; anterior border regularly convex; posterior border distinctly convex. Merus of P6 with three posterior groups of spines/setae and five anterior groups; carpus and propodus lacking.

Posterior border of basis of P7 with very robust ornamentation (11 short and strong spines). Ischium short, reaching 0.32 of outer side of merus; anterodistal border nearly straight on outer side. Carpus and propodus lacking.

Ep3 with posteroventral border regularly rounded, without posteroventral tooth, with one single slender spine followed by a transverse row of two slender spines and a tranverse row of three slender spines on ventrolateral surface; with one setule on posterior border (there could have been more that have been rubbed off).

Urosomite 1 with one pair of anteriorly directed setae, and one pair of posteriorly directed stout spines dorsally; ventrolateral border without strong setae arising from outer side.

Peduncle of uropod 1: outer dorsal border with six short (not very stout) spines consisting of following succession: (1) four short robust spines, (2) the usual penultimate short robust spine, (3) very short space followed by a much stronger distal spine; dorsomedial border with six groups of spines/setae (one seta followed by two×one strong spine paired with one seta, followed by two×one strong single spine, followed by one strong spine paired with one seta); inner ramus with border facing outer ramus, with only one long spine in subdistal position. Peduncle of uropod 2 with five stout outer dorsal spines; dorsomedial border with three strong single spines; inner ramus with border facing outer ramus with only one long spine in subdistal position.

U3 lacking.

Telson of typical morphology; lobes without medial setae.

Descriptiυe notes based on the taeo dried-out slides

Coxa 1 with tip narrowly rounded, without ventral tooth, without ventral notch, without anteroventral angular discontinuity, with well-developed ventral setae, without apical setule.

Coxa 2 with small posterior tooth.

Coxa 3 with anterior and posterior borders slightly converging downwards; posteroventral angle difficult to understand on dried-out microscopical preparation: apparently without tooth but with a setule associated with a notch.

Basis of P5 with both margins straight and parallel. Posteromedian seta group of merus of P5 with major seta rubbed off but with a short accessory seta; posterodistal seta group with one long and strong straight seta (reaching tip of carpus), and one setule.

Basis of P7 with both spines and pappose setae on medial surface, with 11 short spines on posterior border (they look narrower than on specimen in alcohol but this is presumably a drying out artefact). Anterior border of ischium distinctly concave on medial side.

Size. 4.5 mm.

Ecology. On fine sand at 9 m depth.

Distribution. Senegal

Discussion

The specimen in alcohol (found in the same vial as B. cheυreuxi sp. nov.) has apparently been previously dissected on the right side and we have found two slides (unfortunately dried out) labelled ‘‘ B. spec. B. Female ov., Dakar St 333 Chevr.’’ with right appendages, which belong to the same species and presumably to the same specimen. This unique mutilated specimen exhibits similarities with B. griffithsi sp. nov. and perhaps falls within the range of variation of the latter. However, due to the considerable distance between the sampling localities of both forms, this seems unlikely. Bathyporeia griffithisi sp. nov. has a pseudorostrum distally narrow and regularly rounded, whilst it is bluntly subquadrate and not especially narrow in Bathyporeia sp. The coxa 2 is narrower in B. griffithsi sp. nov. than in Bathyporeia sp. On the posterior border of the basis of P7, the proximal and distal spines are replaced by setae in B. griffithsi sp. nov. while there are only spines in Bathyporeia sp. Finally, Bathyporeia griffithsi sp. nov. has usually two pairs of posterior spines on the dorsal part of the first urosomite (three specimens of four) while there is a single one in Bathyporeia sp. More material is necessary to settle the identity of Bathyporeia sp., which may be a new species.