Gubernatoriana thackerayi Pati, 2016

Pati, S. K., Thackeray, T. & Khaire, A., 2016, Five new species of freshwater crabs of the genera Ghatiana Pati & Sharma, 2014, and Gubernatoriana Bott, 1970 (Crustacea, Decapoda, Brachyura: Gecarcinucidae Rathbun, 1904) from the Western Ghats, India, Zootaxa 4083 (4), pp. 569-586 : 580-583

Gubernatoriana thackerayi Pati n. sp.

( Figs. 9 , 10 )

Type material. INDIA: adult male, holotype (cw 9.58 mm, cl 7.82 mm, ch 4.14 mm, fw 3.40 mm), Raghuvir Ghat, ca. 3 km south west of Shindi village, Khed taluk, Ratnagiri district, Maharashtra (17.698° N and 73.589° E), altitude 499 m, 5 July 2015, coll. Tejas Thackeray (ZSI, WRC-C.1515); paratypes, one male (cw 10.16 mm, cl 7.90 mm, ch 4.48 mm, fw 3.52 mm) and seven females (cw 10.50–13.10 mm, cl 8.28–10.02 mm, ch 4.80–5.70 mm, fw 3.62–4.32 mm), same collection data as holotype (ZSI, WRC-C.1516).

Diagnosis. Carapace quadrate (cw/cl = 1.2–1.3); dorsal surface smooth, violet-red coloured; anterolateral margin short, smooth, cristiform; posterolateral margin slightly convergent, with fine, oblique striations; front strongly deflexed, narrow (fw/cw = 0.33–0.4); epigastric cristae faintly visible; postorbital cristae indistinct; exorbital angle triangular, distinct, with long outer margin, ca. 2 times length of inner margin; epibranchial tooth visible as weak notch; frontal median triangle incomplete; epistomal median lobe broadly triangular with acute apex, lacking median tooth ( Figs. 9A, B ). Fingers of chelipeds broadly rounded or spoon tipped ( Fig. 9D ). Suture between male thoracic sternites s2/s3 indistinct, suture between sternites s3/s4 missing except for two short lateral grooves ( Figs. 9C, F ). Male abdomen narrowly T-shaped; sixth abdominal somite slightly broader than long, nearly equal to telson length; telson short; male sternoabdominal cavity deep, long, extending beyond level of bases of third maxillipeds ( Figs. 9C, G ). G1 with stout, cone-shaped, short terminal article, ca. 0.33 times length of subterminal segment, tip straight ( Figs. 10A–C ). G2 with very short or vestigial terminal article ( Fig. 10D ).

Description of holotype. Carapace quadrate (cw/cl = 1.2); dorsal surface smooth; anterolateral carapace gently inflated in frontal view; anterolateral margin short, smooth, cristiform; posterolateral margin slightly convergent, with fine, oblique striations; front strongly deflexed, squarecut, nearly flat, frontal margin nearly straight, narrow (fw/cw = 0.4); epigastric cristae faintly visible, smooth; postorbital cristae indistinct; exorbital angle triangular, distinct, with long outer margin, ca. 2 times length of inner margin; epibranchial tooth visible as weak notch; postorbital region shallow; branchial regions gently inflated; subhepatic region smooth; cervical grooves indistinct; mesogastric groove long, extending to frontal region, with slight bifurcation posteriorly; Hgroove visible, shallow; frontal median triangle incomplete; epistomal median lobe broadly triangular with acute apex, lacking median tooth ( Figs. 9A, B ).

Chelipeds unequal; left chela slightly larger, smooth; teeth on fingers small, blunt, rounded; small gape when tips of major chela in contact; fingers of chelipeds broadly rounded or spoon tipped ( Fig. 9D ); length of dactylus greater than length of upper margin of palm; carpal spine small, blunt; outer surface of merus slightly rugose. Ambulatory legs (p2–p5) long with fine, long tuft of brownish bristles on anterior margin of carpus, propodus, dactylus, posterior margin of propodus, dactylus; dactylus (p2–p5) equal in length to propodus; longest propodus (p4) two times as long as broad ( Fig. 9E ).

Suture between male thoracic sternites s2/s3 indistinct, suture between sternites s3/s4 missing except for two short lateral grooves ( Figs. 9C, F ).

Male abdomen narrowly T-shaped; fifth abdominal somite distinctly broader than long, with concave lateral margins; sixth abdominal somite slightly broader than long, nearly equal in length to telson, with slightly concave lateral margins; telson short, broadly triangular with almost straight outer margins; male sternoabdominal cavity deep, long, extending beyond level of bases of third maxillipeds ( Figs. 9C, G ).

Mandibular palp with two joints, terminal joint bilobed; exopods of first, second maxillipeds with long flagellum; exopod of third maxilliped lacking flagellum, longer than ischium; ventral sulcus on ischium distinct, not parallel to inner margin; merus with rounded anterior external angle, depression towards inner sides ( Fig. 9H ).

G1 with stout, cone-shaped, short terminal article, ca. 0.33 times length of subterminal segment, with straight tip, joint between terminal article, subterminal segment clear; subterminal segment broader than terminal article, basal two-thirds broader than distal one-third ( Figs. 10A–C ). G2 conspicuously short with very short or vestigial terminal article; proximal half portion of basal segment much stouter than distal half portion ( Fig. 10D ).

Live colour. Carapace and ambulatory legs are violet-red, chelipeds orange-red ( Fig. 2D ). Specimens preserved in ethanol have red-orange carapace and ambulatory legs, and orange chelipeds ( Fig. 9A ).

Paratypes. Paratypes are almost undistinguishable in morphology from the holotype. All the female paratypes (ZSI, WRC- C.1516) have chelipeds that are nearly equal in size. The sixth abdominal somite of the male paratype (ZSI, WRC- C.1516) has almost straight lateral margins.

Etymology. The species is named after Mr. Tejas Thackeray, a wildlife conservationist and the collector of the type specimens.

Type locality. Raghuvir Ghat, near Shindi village, Khed taluk, Ratnagiri district, Maharashtra (17.698° N and 73.589° E) (altitude 499 m).

Remarks. Gubernatoriana thackerayi n. sp. is exceptional amongst congeners due to its striking live colour pattern, with the carapace and ambulatory legs violet-red and orange-red chelipeds ( Fig. 2D ). Gubernatoriana thackerayi n. sp. can be also differentiated from its congeners by the stout, cone-shaped G1 terminal article ( Figs. 10A, C ).

Gubernatoriana thackerayi n. sp. closely resembles its congeners in morphology, particularly G. pilosipes . The cheliped fingers of both species are broadly rounded or spoon tipped ( Fig. 9D ; see Bott 1970: pl. 34, fig. 34 for G. pilosipes ). Gubernatoriana thackerayi n. sp. is easily distinguished from G. pilosipes by the comparatively short ambulatory legs (vs. comparatively long ambulatory legs), indistinct suture between male thoracic sternites s2/s3 (vs. visible suture between male thoracic sternites s2/s3), long male sternoabdominal cavity, extending beyond the level of the third maxilliped bases (vs. short male sternoabdominal cavity, extending beyond the level of the cheliped bases), stout, cone-shaped terminal article (vs. slender, cone-shaped terminal article) ( Figs. 9A, C, F , 10A, C ; see Pati & Sharma 2014b: pl. VIII, figs. 8A–D).

Ecological notes. Specimens were collected from interior of horizontal crevices along the slopes of natural rock formations. The possibility of water accumulation is much less due to the horizontal structure of the crevices. Few rainfed temporary streams were also flowing across the slopes. Crabs were seen active during the day time. Individuals were observed feeding on worms (T. Thackeray, unpublished data).

Geographical distribution. Gubernatoriana thackerayi n. sp. is known only from the type locality, Raghuvir Ghat in Ratnagiri district of Maharashtra.

Figures

FIGURE 2. Live crabs of new species of Ghatiana and Gubernatoriana. A, Ghatiana aurantiaca n. sp. from Amboli; B, Ghatiana splendida n. sp. from Chaukul; C, Gubernatoriana alcocki n. sp. from Vankusawade; D, Gubernatoriana thackerayi n. sp. from Raghuvir Ghat; C, Gubernatoriana waghi n. sp. from Malshej Ghat. Photo credits: A, B, Arjun Kamdar; C, B. V. Jadhav; D, Shailesh Bhosale; E, Rachit Shah.

FIGURE 9. Gubernatoriana thackerayi n. sp., holotype male (ZSI, WRC—C. 1515). A, dorsal view; B, frontal view; C, ventral view; D, left or major cheliped; E, right ambulatory leg (p 4); F, anterior male thoracic sternites; G, male abdomen; H, left third maxilliped. Scale bars = 5 mm (A, C), 2 mm (B, D – G), 1 mm (H).

FIGURE 10. Gubernatoriana thackerayi n. sp., holotype male (ZSI, WRC—C. 1515). A, dorsal view of left G 1; B, ventral view of left G 1; C, dorsal view of left G 1 terminal article; D, left G 2. Scale bar = 0.5 mm.