Habrobathynella vidua, 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 : 29-34

Habrobathynella vidua n. sp.

( Figs 22–26 )

Type material. Holotype Ƥ (dissected on 3 slides) (C5846/2, C5847/2, C5848/2) and 1 paratype Ƥ, dissected on 3 slides [MNHN-Sy40(1–3)], agricultural borewell at Tadepalli village (16o41ʹ32ʹ N 82 o0 2 ʹ24ʹ E; elevation 21 m; water temperature 26°C; pH 8.0) near Vijayawada city in Krishna District, Andhra Pradesh, India, leg. V.R. Totakura, 0 7 July 2008. Additional paratype 3, dissected on 3 slides [MNHN-Sy41(1–3)], another agricultural borewell, about 20 m from the type locality. Leg. V.R. Totakura, 12 October 2008.

Other material examined. 1 3, dissected on three slides (in junior author’s collection), borewell, Kunchanapalli village (16o23ʹ42ʹ N 80o32ʹ28ʹ E; elevation 26 m; water temperature 27°C; pH 7.5), about 3 km from type locality. Leg. V.R. Totakura, 7 February 2010.

Diagnosis. On male thoracopod VIII, both dentate and inner lobes distinctly produced; outer lobe ovate in outline, with a row of denticles on truncate apical margin; exopod claw-like in lateral view and plate-like in anterior, posterior and ventral views. Uropodal sympod with inhomonomous row of serrulate spines, proximal 6–7 spines almost equal in size; ultimate and penultimate spines nearly equal in size but longer and thicker than proximal spines. Maxilla with 1 tiny seta on segment 1 and fairly long but slender claw on segment 2. Pleotelson rounded, without seta. Caudal furca wider than long.

Description of adult female. Total body length 1.7 mm. Body with or without perforations, 8.8 times as long as wide. Head 1.2 times as long as wide, 13.1% longer than first three thoracic segments combined.

Antennule ( Fig. 22 a): 6-segmented; 24.5% longer than head. First segment with 2 dorsal plumose setae and 1 ventral plumose seta on outer distal margin, 1 plumose seta and 1 simple seta disto-ventrally. Second segment with 1 plumose seta on papillate projection on subdistal ventral surface, 3 unequal plumose setae at the same level on dorsal surface and 1 simple seta at distal inner corner. Third segment with 1 long simple seta and 1 plumose seta on subdistal outer margin and 1 simple seta on distal ventral surface. Inner flagellum ovate, 1.5 times as long as wide with 2 apical and 1 long subapical setae. Fourth segment with 2 unequal plumose setae on apophysis and 1 plumose seta and 1 stub seta on dorso-distal margin; apophysis overreaching midlength of fifth segment. Fifth segment with 3 dorsal unequal aesthetascs overreaching sixth segment, and 3 setae at distal inner corner and 1 simple seta at outer distal corner. Sixth segment with 3 unequal aesthetascs and 4 unequal setae.

Antenna ( Fig. 22 b): 2-segmented, proximal segment bare, 0.6 times as long as distal segment; second segment 2.2 times as long as wide, with 1 tiny proximal seta, 2 unequal terminal setae, of which inner one plumose and 1.8 times as long as segment, and 1 tiny subterminal dorsal seta.

Labrum ( Fig. 22 c): dentate margin slightly vaulted on either side, bearing a total of 10 main, nearly uniform, pointed, curved teeth and 1 small tooth on either side. Ventral ornamentation not discernible.

Mandible ( Fig. 22 d): distal part of pars incisiva with 4 unequal teeth. Tooth of ventral edge large. Pars molaris developed into pyriform outgrowth, 1.4 times as long as wide, carrying 2 smooth curved teeth on lateral margin and 3 straight slender pointed teeth in a group at distal end; all teeth articulate and apparently without ornamentation. Palp completely absent.

Paragnath (not figured): as in the preceding species.

Maxillule ( Fig. 22 e–f): with 2 endites; proximal endite small, oval, carrying 3 unequal claw-like pinnate spines on inner distal margin and 1 short subdistal spine. Distal endite subcylindrical, 2.9 times as long as wide and armed with 4 terminal claws, distalmost one large, bent inwards, 2 unequal claws (1 long, 1 short) on inner margin and 3 subterminal setae on outer distal margin.

Maxilla ( Fig. 22 g): 3-segmented, nearly straight; basal segment rectangular, 1.9 times as long as wide, with 1 tiny seta on small protuberance at inner distal corner. Second segment 1.2 times as long as basal segment and armed with 14 simple setae including 2 setae at midlength of inner margin and 1 slender claw-like seta at distal inner corner. Third segment completely fused with terminal sickle-shaped claw, which has finely serrulate inner margin.

Thoracopods I–VII ( Figs 23 a–e, 24a–b): as in H. krishna .

Pleopod 1: absent.

Thoracopod VIII ( Fig. 22 h): small, crescentic lobe.

Pleotelson ( Fig. 25 a): without setae.

Uropod ( Fig. 25 a): sympod 3.3 times as long as maximum width, bearing 8 inhomonomous row of serrulate spines, proximal 6 spines almost equal in size; ultimate and penultimate spines nearly equal in size but longer and thicker than proximal spines. Exopod nearly straight, 43% of sympod length and with 1 apical and 1 subapical unequal barbed setae. Endopod falcate, 65% of sympod length, with 2 equal but short barbed setae at proximal quarter of outer margin; disto-lateral margins ornamented with spinules.

Anal operculum: rounded in lateral view ( Fig. 25 a), medially concave in dorsal view (not illustrated).

Caudal furca ( Fig. 25 a): 0.8 times as long wide, with 1 terminal and 3 inner serrulate spines and 2 unequal dorsal setae; spines without spinules at base; furcal organ small, ventral.

Description of adult male. Total body length of paratype 1.57 mm, body and all appendages except Th. VIII as in female.

Thoracopod VIII ( Figs 25 c–d, 26a–c): subglobular, 1.2 times longer than wide in lateral view. Protopod moderately large. Outer lobe fused with protopod, ovate in outline, with row of fine denticles on apical truncate margin. Both dentate and inner lobes distinctly produced, extending well beyond exopod. Dentate lobe longer than inner lobe and with about 12 denticles in 2 rows ( Figs 25 c–d, 26c). Basipod well defined at base and with disto-lateral seta but without any ornamentation. Exopod developed into highly chitinised clawlike structure (plate-like in ventral view), distinct from basipod and apically denticulate. Endopod represented by a small lateral seta, lying close to exopod.

Variation. Body cuticle varying in thickness between populations. Number of spines borne by the uropodal sympod varies between 8 and 9 ( Fig. 25 a–b); uropodal exopod either straight or somewhat incurved ( Fig. 25 a–b).

Etymology. The specific epithet is derived from the Latin adjective, vidua (= deprived of), alluding to the absence of males at the type locality; gender feminine.

Figures

FIGURE 22. Habrobathynella vidua n. sp., holotype female (b – h), paratype male (a). (a) antennule, dorsal; (b) antenna, dorso-lateral; (c) labrum, dorsal; (d) mandible, lateral; (e) maxillule, ventral; (f) same, latero-ventral; (g) maxilla,

FIGURE 23. Habrobathynella vidua n. sp., holotype female. (a – e) Th. I – V.

FIGURE 24. Habrobathynella vidua n. sp., holotype female. (a – b) Th. VI – VII.

FIGURE 25. Habrobathynella vidua n. sp., holotype female (a) and paratype male (b – d). (a) pleotelson, lateral; (b) uropod, lateral; (c) Th. VIII, latero-external; (d) Th. VIII, latero-internal view.

FIGURE 26. Habrobathynella vidua n. sp., paratype male. (a) Th. VIII, anterior; (b) Th. VIII, posterior; (c) Th. VIII,