New species of Bairdioidea (Crustacea, Ostracoda) from the Southern Ocean and discussions on Bairdoppilata simplex (Brady, 1880),? Bairdoppilata labiata (Müller, 1908) and Bythopussella aculeata (Müller, 1908) * Author Brandão, Simone N. text Zootaxa 2008 1866 373 452 journal article 10.5281/zenodo.183820 287b1420-5c7c-4a05-ae95-e4c9121b51a6 1175­5326 183820 ? Bairdoppilata sp. 1 aff. ? B. labiata ( Müller, 1908 ) (Figs. 3.15, 3.17, 4, 5.E, F, N, 8.B, E, H, I, L, P, Q, 9.G–L, 12.O–Q) 1969 in part Bairdoppilata ( Bairdoppilata ?) simplex , Maddocks: 77–78, Fig. 42 . 2000? Bairdoppilata cf. B. simplex , Dingle : 486, 488, Figs. 2, 3, 5.C, table. 2. Material. 1 A F, Bairdoppilata ( Bairdoppilata ?) simplex ( Brady, 1880 ) , RV Eltanin station 418, 62°39–40’S, 56°8–10’W, 311 to 426m , Ref. 58, USNM 121347 . This living female was illustrated by Maddocks (1969, p. 77, fig. 42B) ; this is Maddocks’ specimen no. 191. 1 A M, Bairdoppilata ( Bairdoppilata ?) simplex ( Brady, 1880 ) , RV Eltanin station 1345, 54°50–51’S, 129°46–48’W, 915 to 1153m , USNM 121348 . This living male was identified and illustrated by Maddocks (1969, p. 77, Fig. 42 A, C–H) ; this is Maddocks’ specimen no. 205. (Herein Figs. 3.17, 4, 5.E, F, 8.E, H, L, P, Q, 9.G–L). 1 RV, ROSSMIZE, # H in 4, ZMH K­ 41363 (Herein Fig. 12 .P–Q). Distribution. Southern Ocean (Atlantic and Pacific Sectors), 196 to 426m . Measurements ( Fig. 4 ) . USNM 121347 : RV, A F L 1.97mm , H 0.97mm . USNM 121348 : LV, A M L 1.70mm , H 0.96mm ; RV L 1.68mm , H 0.90mm . ZMH K­41363: LV, L 1.00mm, H 0.56mm . Remarks . Specimens from the Pacific Sector of the Southern Ocean – one male, USNM 121348 , and off Northern Antarctic Peninsula – one female, USNM 121347 – identified by Maddocks (1969) as B. simplex are included herein. They differ from B. simplex in the same features as B. simplex differs from ? B. labiata (see Remarks from ? B. labiata ). These two specimens are similar to ? B. labiata , but their LV present a more rectilinear outline, with slightly concave anterodorsal margin (instead of slightly convex); dorsal margin of RV presents relatively shorter medial segment ( Figs. 5 .A–F, I–K, N). Additionally, the adult female (USNM 121347 ) is considerably larger than the lectotype of B. simplex . Moreover, the three males of ? B. labiata from the Gausstation (ZMB 13069) present different hemipenis morphology than the male from the Pacific sector of the Southern Ocean (USNM 121348 ). The distal element of specimens collected from the Gausstation is irregular, subtriangular in shape, with a distal “finger­like” process pointing out from the rest of the hemipenis ( Figs. 8 .M–O, 9.A–D). In the specimen from the Pacific Sector of the Southern Ocean the distal element of the hemipenis is elongate, subovate, and the distal process forms a structure similar to a subchela (but not articulated) with the most interior part of the distal element ( Figs. 8 .P, Q, 9.G–L). The chaetotaxy of the appendages (AI, AII, Md, MxI, ApV to VII) and furcae was compared among type specimens of ? B. labiata and ?B. sp. aff. ? B. labiata but no consistent difference was found. In my opinion, these differences in carapace and hemipenis are sufficient for the description of a new species, which, otherwise, should await the collection of more specimens. In addition, it is also possible that both specimens (USNM 121347 , USNM 121348 ), which were collected many thousands of kilometres away from each other, belong to different species. The only RV from Ross Sea (ZMH K­41363) ( Fig. 12 .O–Q) studied herein is different from? B. labiata in being much smaller and presenting a convexity in mouth region of the ventral margin.