BATHYNELLIDAE GROBBEN, 1905

FAMILY BATHYNELLIDAE GROBBEN, 1905 View in CoL

SUBFAMILY GALLOBATHYNELLINAE SERBAN, COINEAU & DELAMARE DEBOUTTEVILLE, 1971

( FIGS 3A, B, F, I, J View Figure 3 , 4A, B, F, G, K, L View Figure 4 , 5A, B, F, G, K, L View Figure 5 , 6A–U View Figure 6 , 7A–L View Figure 7 )

Diagnosis (translated from Serban, Coineau & Delamare Deboutteville, 1971 and Serban, 1989a, b): Antennule (A I) with six or seven segments; antenna (A II) with three or five segments on the endopod (Endp); apical part of paragnaths with thin setae; prehensile mandibular palp of the mandible (Md) with one to three segments and both sexes with similar or different claws on the terminal segment; pars incisiva (incisor process) (‘pars incisiva’) of mandible with two simple teeth and processus incisivus accesorius (molar process); pars molaris of Md normally made of two parts, more or less complex, with simple teeth or teeth with denticles on margins; Endp with three segments on thoracopods (Ths) II, IV, V and VI or with four segments on all pairs; male thoracopod (Th) VII without coxal endite. Penial region (‘región pénienne’) of Th VIII with one lobe and an apically developed frontal projection (Fr.prj) (‘prolongement rostral’) or one lobe, one frontal projection and one large outer lobe (O.lb) (‘lobe externe’); well-developed vertical or inclined basipod (Bsp), generally with an outer protuberance (O.pr) (‘proéminence externe’); exopod (Exp) always present and similar to the exopod of the Th; Endp small and one segmented or absent. Female Th VIII variable, similar to the Bathynellinae (the two rami similar in length) or reduced to two segments (coxopod and Bas); Exp with two terminal setae can be exceptionally smaller than the Endp; coxal seta elongated or reduced. Sympod of the uropod with three or four spines (‘épines’); Endp with two or four claws (‘griffes’). Furcal rami with second spine, longer than the other four in almost all cases.

Gallobathynellinae currently includes 11 genera ( Table 1), and 25 species (see Supporting Information, Appendix S1), all from Europe: Iberian Peninsula ( Portugal and Spain), France, Italy, Switzerland and Germany.

Morphological differences among genera and species are shown in Table 4.

SUBFAMILY BATHYNELLINAE GROBBEN, 1905

( FIGS 3C, D, G, H, K, L View Figure 3 , 4C, D, H, I, M, N View Figure 4 , 5C, D, H, I, M, N View Figure 5 )

Diagnosis (translated from Serban, Coineau & Delamare Deboutteville, 1971): For the diagnosis of the genus Bathynella , the mandible and the male thoracopod VIII are primary characters. Penial region of male Th VIII ( Fig. 5C View Figure 5 ) composed of three or four lobes forming penial complex (an anterior plate, inner lobe and small lobe, which can sometimes be merged to a fourth, parapean lobe, e.g. in the subgenus Lombardobathynella Serban, 1973 ), Bsp well developed and merged to the penial complex on anterior side of the proximal region, Bsp main axis parallel to penial lobes, Endp and Exp present and one segmented; female Th VIII generally composed of

Terminology of the male Thoracopod VIII translated from Serban:‘region pénienne’ = penial region;‘plaque antérieure’ = front plate (Fr. pl.); ‘lobe’ = lobe (Lb); ‘prolongament rostral’ = frontal projection (fr.prj.); ‘lobule interne’ = inner lobe (I. lb.); ‘lobule externe’ = outer lobe (O.lb.); ‘petit lobe’ = small lobe (S. lb.); ‘proéminence externe’ = outer protuberance (O. prt.). Abbreviations: A I, antennule; A II, antenna; Endp, endopod; Exp, exopod; L, large; Md., mandible; Sgt, segment; Ths, thoracopods; Urp, uropod.

protopod, Exp, and Endp (usually one segmented); mandibular palp always three segmented; Endp of all seven pairs of thoracopods four segmented. Protopod of female Th VIII ( Fig. 5M View Figure 5 ): two segmented (coxa and Bsp), with precoxa and coxal epipod, Endp formed by a single short segment, Exp well developed and similar to the Exp of the ambulatory thoracopods. Masticatory part of Md ( Fig. 4C View Figure 4 ): with four teeth on pars molaris (identical morphology in all of the ten well-described species), two teeth on pars incisiva and accessory incisor process formed by one tooth and sometimes small denticles.

The subfamily Bathynellinae includes ten genera and an undetermined number of species and subspecies (~65, 45 of which have been identified as members of the genus Bathynella (see Table 1; Supporting Information, Appendix S1). The subfamily occurs on all continents except Africa and Antarctica, but most species have been found in Europe and Asia. As discussed above, a morphological and molecular reassessment is needed to resolve the substantial taxonomic problems within Bathynellinae . The confirmed distribution area of the genus Bathynella includes the territories between Transcaucasia and the North of France (Serban, 1975, 2000).

The morphological differences among the three genera and species included in this study can be found in Table 4.

SUBFAMILY AUSTROBATHYNELLINAE DELAMARE DEBOUTTEVILLE & SERBAN, 1973

( FIGS 3E, M View Figure 3 , 4E, J, P View Figure 4 , 5E, J, P View Figure 5 )

Diagnosis (translated and modified from Serban & Coineau, 1975): Labrum sexually dimorphic; pars incisiva of Md with two to four apical teeth; four-segmented Endp of Ths; penial region of the male Th VIII with only one lobe, the outer lobe more or less well developed, two rami, variable in size and structure among species, and located in a different part compared with Bathynellinae ; Endp one or two segmented; Exp of Ths I–VII differ from Bathynellidae . Female Th VIII with only one ramus; third segment of Endp of A II very small; Md with more teeth than European species from other subfamilies, pars incisiva similar to Parabathynellidae ; labrum sexually dimorphic (in A. patagonica ); Endp of Ths four segmented; sympod of uropod with four large spines; uropodial claw (‘griffe uropodial’) of Bathynellinae and Gallobathynellinae

Data from this study and literature. Data from original description of G. coiffaiti , G. boui , G. tarissei and A. stammeri complimented by A.I. Camacho (pers. observ.). Abbreviations: Sgt n A II, antenna segment number; Medial St exp, medial seta on exopod;A I:A II, relative lengths of antennule and antenna; Distal part, paragnath, shape of the distal part of the paragnath; Sgt n Md palp, mandibular palp segment number; Sgt n endp Ths I–VII, number of segments of endopod of thoracopods I–VII; St n plp, pleopod setae number; Spi n symp, uropodial sympod spine number and description; Claw n endp, uropodial endopod claw number; St plt, qualitative description of pleotelson setae; X St, X Stal end?, unknown data.

reduced, but in Austrobathynellinae present as uropodial seta ‘x’.

Of the three Bathynellidae subfamilies, Austrobathynellinae has the fewest described genera, and only three can be assigned to the subfamily: Transvaalthynella and Transkeithynella from Africa and Austrobathynella from South America ( Table 1). Two Chilean species ( Bathynella cautinensis and Bathynella grossei ) that were initially assigned to the genus Bathynella may also belong to the Austrobathynellinae .

Morphological differences among genera and species are presented in Table 4.