Ghatiana splendida, Pati & Thackeray & Khaire, 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 : 575-577

Ghatiana splendida n. sp.

( Figs. 5 , 6 )

Type material. INDIA: adult male, holotype (cw 20.14 mm, cl 14.84 mm, ch 10.32 mm, fw 8.04 mm), Near Khamada Temple, Chaukul, ca. 10 km south east of Amboli, Sawantwadi taluk, Sindhudurg district, Maharashtra (15.878° N and 74.031° E), altitude 853 m, 7 July 2015, coll. Tejas Thackeray (ZSI, WRC-C.1511); paratypes, two males (cw 15.60–19.52 mm, cl 11.68–14.48 mm, ch 8.58–10.10 mm, fw 6.24–8.04 mm) and two females (cw 14.66–17.12 mm, cl 11.00– 12.46 mm, ch 7.56–9.60 mm, fw 5.60–6.70 mm), same collection data as holotype (ZSI, WRC-C.1512).

Diagnosis. Carapace slightly broader than long (cw/cl = 1.3–1.4), highly arched (ch/cl = 0.69–0.77), narrow posteriorly; dorsal surface entirely smooth, deep pink coloured; anterolateral margin long, curved, smooth, entire or cristate; posterolateral margin with short, indistinct, oblique striations; front vertically deflexed, broad (fw/cw = 0.4); epigastric cristae distinct, low, broad, blunt; postorbital cristae indistinct; exorbital angle low, indistinct; epibranchial tooth indistinct; frontal median triangle incomplete; epistomal median lobe with rounded apex, lacking median tooth ( Figs. 5A, B ). Suture between male thoracic sternites s2/s3 indistinct, suture between sternites s3/s4 missing except for two short lateral grooves ( Figs. 5C, F ). Male abdomen long, T-shaped; sixth abdominal somite longer than broad, with lateral margins gently diverging distally; telson long ( Figs. 5C, G ). G1 slightly curved outwards; terminal article straight, cylindrical, long, ca. 0.45 times length of subterminal segment ( Figs. 6A–C ). G2 terminal article very short or vestigial ( Fig. 6D ).

Description of holotype. Carapace slightly broader than long (cw/cl = 1.4), highly arched (ch/cl = 0.70), narrow posteriorly; dorsal surface entirely smooth except for few indistinct striations on lateral sides; anterolateral carapace inflated in frontal view; anterolateral margin long, curved, smooth, entire; posterolateral margin with short, indistinct, oblique striations; front depressed at middle, vertically deflexed, broad (fw/cw = 0.4); frontal margin straight; epigastric cristae distinct, low, broad, blunt; postorbital cristae indistinct; exorbital angle low, indistinct; epibranchial tooth indistinct or visible as weak notch; postorbital region shallow; branchial regions inflated, almost smooth; subhepatic region with fine striations; cervical grooves indistinct; mesogastric groove long, deep, wide, extending towards frontal region, bifurcate posteriorly; H-groove faintly visible; frontal median triangle incomplete with only dorsal margin; epistomal median lobe broadly triangular with rounded apex, lacking median tooth ( Figs. 5A, B ).

Chelipeds smooth, unequal; left chela much larger; each finger of major cheliped with only six or seven distinct, blunt teeth, fingers meeting only at tip, leaving large gape ( Fig. 5D ); dactylus of major cheliped equal in length to palm; palm almost as high as long; carpal spine distinct, blunt; carpus devoid of bristles; outer surface of merus slightly rugose. Ambulatory legs (p2–p5) long with fine, small tuft of brownish bristles mostly on margins; dactylus (p3–p5) longer than propodus; longest propodus (p3) 2.5 times as long as broad ( Fig. 5E ).

Suture between male thoracic sternites s2/s3 indistinct, suture between sternites s3/s4 missing except for two short lateral grooves; s1–s4 sparsely setose ( Figs. 5C, F ).

Male abdomen elongated, T-shaped; fifth abdominal somite broader than long with concave lateral margins, distal width shorter than proximal width; sixth abdominal somite longer than broad, with lateral margins gently diverging distally, proximal width equal to distal width; telson elongated, broadly rounded at apex; male sternoabdominal cavity deep, conspicuously long, extending much beyond level of bases of third maxillipeds ( Figs. 5C, 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 indistinct; merus quadrangular, slightly depressed, anterior external angle of merus right angled ( Fig. 5H ).

G1 short, slightly curved outwards; terminal article straight, cylindrical, long, ca. 0.45 times length of subterminal segment, tip pointed; subterminal segment broader than terminal article, basal half broader than distal half ( Figs. 6A–C ). G2 short with very short or vestigial terminal article; proximal half of basal segment distinctly broader than distal half ( Fig. 6D ).

Live colour. Carapace and chelipeds are deep pink, and ambulatory legs are orange ( Figs. 2B , 5A ).

Paratypes. Paratype specimens are almost identical to the holotype in carapace morphology and gonopod structures. All paratypes except the larger male (ZSI, WRC- C.1512) have a cristate anterolateral margin and visible epibranchial tooth. Major chelipeds of the female paratypes have a higher number (9 or 10) of distinct, blunt teeth, and the gape formed between their fingers is smaller than that of the holotype and male paratypes.

Etymology. The specific epithet is derived from the Latin splendidus meaning ‘gorgeous or splendid’, referring to striking deep pink colour of the carapace and chelipeds.

Type locality. Chaukul, ca. 10 km south east of Amboli, Sawantwadi taluk, Sindhudurg district, Maharashtra (15.878° N and 74.031° E) (altitude 853 m).

Remarks. The colour pattern of G. splendida n. sp. is unique among congeners i.e. carapace and chelipeds are deep pink, and ambulatory legs are orange ( Figs. 2B , 5A ). Ghatiana splendida n. sp. can be differentiated among congeners by the following suite of characters: carapace with long anterolateral margin; epistomal median lobe with rounded apex; male thoracic sternites s1, s2 sparsely setose; sixth male abdominal somite with lateral margins gently diverging distally; G1 terminal article short, ca. 0.45 times the length of the subterminal segment ( Figs. 5A– C, F, G , 6A ).

While many morphological features and gonopod structures of G. splendida n. sp. and G. aurantiaca appear superficially similar, the two species are nevertheless distinguished by the contrasting colours of the ambulatory legs (orange) and carapace, chelipeds (deep pink), long anterolateral margin, sparsely setose male thoracic sternites s1, s2, and distally, gently diverging lateral margins of the sixth male abdominal somite of the former ( Figs. 2B , 5A, F, G ) as compared to the uniform orange-red body colour, short anterolateral margin, heavily setose male thoracic sternites s1, s2, and distally, gently converging lateral margins of the sixth male abdominal somite of the latter (see Pati & Sharma 2014a: figs. 2A, C, 3A, B, 8A).

Ecological notes. Ghatiana splendida n. sp. was observed either foraging or resting in crevices of basaltic rock formations along the slopes of a vast mountain plateau (T. Thackeray, unpublished data). Some individuals were found to share the same crevice. Crevices and holes contained rainwater. Mountain plateau is exposed to strong wind and heavy rainfall during the monsoon, but remain quite dry during rest of the year. Therefore, moist crevices of the natural rock formations might be the hiding place for this species in adverse conditions.

Geographical distribution. Ghatiana splendida n. sp. is known only from the type locality, Chaukul near Amboli in Sindhudurg district of Maharashtra. Individuals were also seen near the Hiranyakeshwar Temple, approximately 3 km south east Amboli during January 2010 (K. Patil, personal communication).

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 5. Ghatiana splendida n. sp., holotype male (ZSI, WRC—C. 1511). A, dorsal view; B, frontal view; C, ventral view; D, left or major cheliped; E, right ambulatory leg (p 3); 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 6. Ghatiana splendida n. sp., holotype male (ZSI, WRC—C. 1511). A, dorsal view of right G 1; B, ventral view of right G 1; C, dorsal view of right G 1 terminal article; D, right G 2. Scale bar = 0.5 mm.