Habrobathynella vaitarini, Reddy, Yenumula Ranga & Totakura, Venkateswara Rao, 2010

Reddy, Yenumula Ranga & Totakura, Venkateswara Rao, 2010, A taxonomic revision of the genus Habrobathynella Schminke, 1973, with the description of four new species from southeastern India (Crustacea, Malacostraca, Bathynellacea), Zootaxa 2532, pp. 1-54 : 13-20

Habrobathynella vaitarini n. sp.

( Figs 9–14 )

Type material. Holotype 3 (dissected on 3 slides) (C5836/2, C5840/2, C5841/2), allotype Ƥ (dissected on 3 slides) [MNHN-Sy26(1–3)] and 7 paratypes: 2 Ƥ (dissected on 3 slides each) [MNHN-Sy27(1–3), MNHN- Sy28(1–3)]; 2 Ƥ (in alcohol in 1 vial) (MNHN-Sy44); 2 33 (dissected on 3 slides each) [(MNHN-Sy30(1– 3), MNHN-Sy31(1-3)] and 1 3 (whole-mounted) (MNHN-Sy32), River Krishna at Madipadu village (16°48ʹ50ʹ N 80°04ʹ22ʹ E; elevation 40 m; water temperature 32°C; pH 7.5), in Guntur District, Andhra Pradesh, India, leg. V.R. Totakura, 27 July 2008.

Other material examined. 1 3, 2 Ƥ in alcohol in 1 vial (MNHN-Sy45), River Krishna at Pulichintala village (16°49ʹ22ʹ N 80°04ʹ0 3ʹ E; elevation 44 m; water temperature 32°C; pH 7.5), in Guntur District, Andhra Pradesh, India, leg. V.R. Totakura, 27 July 2008; 1 Ƥ (in ethanol in junior author’s collection), leg. V.R. Totakura, 12 October 2008; 1 Ƥ (dissected on 3 slides) [(MNHN-Sy29(1-3)], 3 Ƥ (in alcohol in 1 vial) (MNHN-Sy44), River Krishna at Challagariga village (16°45ʹ32ʹ N 80°07΄35΄ E; elevation 39 m) in Guntur District, Andhra Pradesh, India, leg. V.R. Totakura, 27 July 2008.

Diagnosis: Male thoracopod VIII subglobular, with dentate and inner lobes only moderately produced; outer lobe smooth, narrow and shorter than basipod; exopod small, appearing as incurved claw laterally. Basipod unornamented, basipodal seta lying apart from endopodal seta. Uropodal sympod with inhomonomous row of 7 spines, ultimate spine being longer and thicker than proximal ones. Setae on uropodal endopod short. Maxilla with 3 unequal setae on segment 1 and fairly long claw-like seta on segment 2. Pleotelson slightly produced postero-laterally; setae shorter than furca. Caudal furca longer than wide

Description of adult male. Total body length of holotype 1.25 mm, of paratypes 1.06–1.3 mm, mean 1.2 mm (n = 4). Body ( Fig. 9 )) elongate, heavily chitinised and perforated, 9.1 times as long as wide. Head 1.2 times as long as wide, 14.2% longer than first three thoracic segments combined.

Antennule ( Figs 10 a, 11a): 6-segmented; 25.2% longer than head. First segment with 2 dorsal plumose and 1 ventral setae at subdistal outer margin, 1 plumose seta at outer distal corner, 1 long simple seta on dorsal surface. Second segment with 1 plumose seta on papillate projection on ventral surface, 2 dorsal plumose setae at subdistal outer margin, 1 simple seta at inner distal corner. Third segment with 1 small dorsal seta at inner distal corner, 1 small plumose seta and 1 long simple seta at about outer distal corner. Inner flagellum longer than wide, with 2 unequal setae on apical margin and 1 long subapical seta. Fourth segment with 2 unequal plumose setae on apophysis and 1 plumose seta near inner distal corner and 1 stub seta. Fifth segment with 3 unequal ventral aesthetascs overreaching ultimate segment and 2 setae on distal dorsal surface and 2 setae at inner distal corner. Sixth segment with 3 aesthetascs and 4 unequal setae.

Antenna ( Fig. 10 b): 2-segmented, proximal segment bare, 0.4 times as long as distal segment; second segment 1.8 times as long as wide, with 1 tiny proximal seta, 2 unequal terminal setae, of which inner one plumose and 2.5 times as long as segment, and 1 subterminal dorsal seta.

Labrum ( Figs 10 c, 11b): dentate margin vaguely vaulted on either side, bearing 10 main nearly uniform, pointed, curved teeth, and 1 small tooth on either side. Also, 4 rows of fine spinules (ctenidia) and 3 teats on ventral surface, as illustrated.

Mandible ( Figs 10 d–f, 11c): distal part of pars incisiva with 4 unequal teeth. Tooth of ventral edge large, lateral margin finely denticulate. Pars molaris developed into pyriform outgrowth, 1.4 times as long as wide, carrying 2 finely denticulate, curved unequal teeth and some setules on inner margin, proximal tooth larger, and 3 somewhat strong, unequal, finely denticulate teeth in a group at distal end, all teeth articulate, distal outer margin of pars molaris with very tiny denticles. Palp completely absent.

Paragnath ( Fig. 10 g) as in H. krishna .

Maxillule ( Fig. 10 h–i): with 2 endites; proximal endite oval, carrying 3 nearly equal claw-like pinnate spines on inner distal margin and 1 short smooth subdistal spine. Distal endite strong, 2.2 times as long as maximum width and armed with 4 terminal claws, distalmost one large, bent inwards, 2 unequal claws (1 long, 1 reduced) on inner margin and 3 subterminal setae on outer distal margin.

Maxilla ( Figs 10 j–k, 11d): 3-segmented, somewhat bent inwards; basal segment 1.6 times as long as wide, with 3 unequal slender setae on small protuberance at inner distal corner. Second segment 1.2 times as long as basal segment and armed with 13 simple setae including 2 setae at mid-inner margin and 1 long prehensile claw-like seta at inner distal corner. Third segment almost completely fused with terminal claw, which has finely serrulate inner margin.

Thoracopods I–VII ( Figs 12 a–e, 13a–b): as in H. krishna . except for proportions of exo- and endopodal segments.

Thoracopod VIII ( Fig.14 a–b): subglobular, 1.3 times as long as wide; in lateral view, protopod large; outer lobe conical, fused with protopod and extending beyond midlength of basipod. Penile region at the same level as exopod. Dentate lobe slightly longer than inner lobe and with about 6 denticles. Inner lobe ovate in outline. Basipod well defined at base, with 1 seta at outer distal angle and without ornamentation on inner distal region. Exopod small, incurved claw, heavily chitinised, distinct from basipod, closely pressed against dentate lobe and carrying 2 large denticles. Endopod represented by a small seta lying close to exopod.

cate, 56% of sympod length, disto-lateral margins ornamented with spinules and with 2 unequal, short barbed setae at proximal quarter of outer margin, longer seta 0.3 times as long as endopod.

Pleotelson ( Fig. 13 c–e): with 1 seta on either side at base of caudal furca; seta 0.6 times as long as caudal furca, in lateral view.

Anal operculum: somewhat protruded in lateral view ( Fig. 13 d), medially concave in ventral view ( Fig. 13 e).

Caudal furca ( Fig. 13 c–e): longer than maximum width, with 1 terminal and 3 inner serrulate spines and 2 unequal dorsal plumose setae; each spine with transverse row of very tiny spinules at base; furcal organ small, ventral.

Description of adult female. Total body length of allotype 1.29 mm, of paratypes 0.9–1.4 mm, mean 1.3 mm (n = 4). Body and all appendages except Th. VIII as in male.

Thoracopod VIII ( Fig. 14 c): small, somewhat triangular lobe.

Variation. Shape of the female thoracopod VIII varies slightly ( Fig. 14 c–d). No variation in the number of spines on uropodal sympod ( Fig. 13 c, e).

Etymology. The specific epithet is derived from the Vedic term Vaitarini , which is equivalent to the Greek Styx , meaning a river in the underground; proposed here as a noun in apposition to the generic name.

Figures

FIGURE 9. Habrobathynella vaitarini n. sp., paratype male, habitus, lateral.

FIGURE 10. Habrobathynella vaitarini n. sp., male, holotype (b – e, g – k) and paratype (a, f). (a) antennule, dorso-lateral; (b) antenna, dorsal; (c) labrum, ventral; (d) mandible, ventral; (e) same, pars incisiva, frontal; (f) same, pars incisiva and tooth of ventral edge, ventral; (g) paragnath, ventral; (h) maxillule, dorsal; (i) same, distal endite, ventral; (j) maxilla, lateral; (k) same (from other appendage of the same pair), third segment, lateral.

FIGURE 11. Habrobathynella vaitarini n. sp., holotype male (a – d). (a) antennule, ventral; (b) labrum, ventral; (c) mandible, dorsal; (d) maxilla, lateral.

FIGURE 12. Habrobathynella vaitarini n. sp., holotype male. (a – e) Th. I – V.

FIGURE 13. Habrobathynella vaitarini n. sp., holotype male (a – c), allotype female (d) and paratype male (e). (a – b) Th. VI – VII; (c) pleotelson, dorso – lateral; (d) same, lateral; (e) same, ventral.

FIGURE 14. Habrobathynella vaitarini n. sp., holotype male (a – b), allotype female (c) and paratype female (d). (a) Th. VIII, latero-external; (b) Th. VIII, latero-internal; (c – d) Th. VIII, lateral.