Ghatiana aurantiaca, Pati & Sharma, 2014

Pati, S. K. & Sharma, R. M., 2014, Description of Ghatiana, a new genus of freshwater crab, with two new species and a new species of Gubernatoriana (Crustacea: Decapoda: Brachyura: Gecarcinucidae) from the Western Ghat Mountains, India, Journal of Natural History 48 (21), pp. 1279-1298 : 1289-1292

Ghatiana aurantiaca sp. nov.

( Figures 2A–C , 3A–H , 8 A )

Type specimens

Holotype: male (cw 17.10 mm, cl 12.14 mm, ch 7.76 mm, fw 6.42 mm), coll. P.S. Bhatnagar and party (ZSI, WRC-C.1129), Forest Rest House, Phansad Wildlife Sanctuary, Raigad district , Maharashtra, India, 18°25 ′ 27.912 ″ N, 72°56 ′ 53.1672 ″ E, alt. 244 m; paratypes: 2 males (cw 14.52–15.64 mm, cl 10.64–11.30 mm, ch 6.84– 7.30 mm, fw 5.64–6.04 mm) and 2 females (cw 10.94–15.64 mm, cl 7.94–11.12 mm, ch 4.70–7.26 mm, fw 4.30–6.00 mm) (ZSI, WRC-C.828), same data as holotype.

Diagnosis

Carapace slightly broader than long (cl/cw = 0.71–0.73); anterolateral margin curved with smooth, cristiform, thick, oblique striations; epigastric crests distinct, low, broad, blunt; postorbital crests indistinct; epibranchial tooth indistinct; mesogastric groove long, deep, extending into frontal region up to frontal margin; frontal median triangle incomplete with only dorsal margin; epistomal median lobe broadly triangular with rounded apex, lacking median tooth ( Figure 2A,B ). Suture between thoracic sternites s2/s3 indistinct and between s3/s4 visible as grooves on sides only; s1, s2 with bunch of setae ( Figures 2C , 3A ). Male abdomen elongated T-shape; fifth abdominal somite broader than long; sixth abdominal somite longer than broad; telson longer than sixth abdominal somite ( Figures 2C , 3B ). G1 short, slightly curved outward with long terminal article (0.45 times length of subterminal segment); tip pointed; subterminal segment much broader than terminal article, basal two-thirds much broader than distal one-third ( Figure 3E–G ). G2 short with very short or vestigial terminal article ( Figure 3H ). Carapace orange red in living animals ( Figure 8A ).

Description

Carapace slightly broader than long (cw/cl 1.4), narrow posteriorly; highly arched (ch/cl 0.64), anterolateral carapace inflated in frontal view; dorsal carapace surface rugose on lateral sides; anterolateral margin curved with smooth, cristiform, thick, oblique striations; posterolateral margin with fine, oblique striations; front depressed, vertically deflexed, broad, fw/cw 0.4; frontal margin slightly undulating; epigastric crests distinct, low, broad, blunt; postorbital crests indistinct; external orbital angle poorly developed; epibranchial tooth indistinct, very close to level of supraorbital margin; postorbital region slightly deep; branchial regions inflated, rugose; subhepatic region with fine striations; cervical grooves poorly developed, interrupted; mesogastric groove long, deep, extending to frontal margin, bifurcated posteriorly; H-groove visible; frontal median triangle incomplete with only dorsal margin; epistomal median lobe broadly triangular with rounded apex, lacking median tooth ( Figure 2A,B ).

Chelipeds unequal; right chela much larger; smooth; teeth on fingers blunt, almost of equal size; dactylus shorter than palm; fingers of larger chela meet only at tip ( Figure 3C ); carpal spine distinct, blunt; carpus devoid of bristles; outer surface of merus rugose.

Ambulatory legs (p2–p5) long with very fine, small tuft of brownish bristles with yellowish tips mostly on margins; dactylus (p4 and p5) longer than propodus; longest propodus (p3) three times as long as broad.

Suture between thoracic sternites s2/s3 indistinct, suture between sternites s3/s4 missing except for two short lateral grooves; s1, s2 heavily setose ( Figures 2C , 3A ).

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, shorter than telson with slightly convex lateral margins, proximal width equal to distal width; telson elongated, broadly rounded at apex ( Figures 2C , 3B ); male sternoabdominal cavity deep, very long, extending much beyond level of bases of third maxillipeds ( Figure 2C ).

Exopod of first, second maxillipeds with long flagellum; exopod of third maxilliped lacking flagellum, longer than ischium, ventral sulcus on ischium indistinct, merus quadrangular, anterior external angle of merus right angled, slightly depressed ( Figure 3D ). Mandibular palp with two joints, terminal joint bilobed.

G1 short, slightly curved outward with long terminal article (0.45 times length of subterminal segment); terminal article narrower than subterminal segment, tip pointed; subterminal segment broader than terminal article, basal two-thirds broader than distal third ( Figure 3E–G ). G2 short with very short or vestigial terminal article; proximal half of basal segment distinctly broader than distal half ( Figure 3H ).

Colour

Live animals have an orange-red carapace and chelipeds ( Figure 8A ); specimens preserved in ethanol have a yellow-brown carapace and chelipeds.

Etymology

The specific epithet derived from the Latin word aurantiacus meaning ‘orange-red’, refers to the orange-red colour of the live crab.

Remarks

Ghatiana aurantiaca sp. nov. is similar to G. hyacintha sp. nov. in general carapace morphology and G1 structure. However, these two species are clearly differentiated by the following characters: orange-red colour when alive (vs violet when alive); carapace more transversely elongate in appearance, cw/cl 1.4 (vs carapace less transverse and more squarish in appearance, cw/cl 1.3); epistomal median lobe broadly triangular with rounded apex (vs epistomal median lobe broadly triangular with slightly acute apex); thoracic sternites s3/s4 smooth, lacking setae (vs sternites s3/s4 highly setose); short G1 terminal article 0.45 times length of subterminal segment (vs long terminal article 0.55 times length of subterminal segment); basal two-thirds of G1 subterminal segment broader than distal one-third (vs basal half of G1 subterminal segment broader than distal half) ( Figures 2A,B , 3A,E , 4A,B , 5A,E , 8A,B ).

Ecological notes

Ghatiana aurantiaca lives on land inside cavities of laterite boulders, and inside holes in tree trunks (present study). This crab species is active during the night in the rainy season when it is often seen walking on the ground, on laterite boulders, or climbing up tree trunks (Pati and Sharma, unpublished data).

Distribution

Known only from the type locality.

Figures

Figure 2. Ghatiana aurantiaca sp. nov., holotype male (ZSI, WRC-C.1129). (A) Dorsal view; (B) frontal view; (C) ventral view. Scale bars: 10 mm.

Figure 3. Ghatiana aurantiaca sp. nov., holotype male (ZSI, WRC-C.1129). (A) Anterior thoracic sternites; (B) abdomen; (C) right cheliped; (D) left third maxilliped; (E) dorsal view of right G1; (F) ventral view of right G1; (G) dorsal view of terminal article of right G1; (H) right G2. Scale bars: 5 mm (A, B); 10 mm (C); 2.5 mm (D) and 1 mm (E–H).

Figure 4. Ghatiana hyacintha sp. nov., holotype male (ZSI, WRC-C.1130). (A) Dorsal view; (B) frontal view; (C) ventral view. Scale bars: 10 mm.

Figure 5. Ghatiana hyacintha sp. nov., holotype male (ZSI, WRC-C.1130). (A) Anterior thoracic sternites; (B) abdomen; (C) right cheliped; (D) left third maxilliped; (E) dorsal view of right G1; (F) ventral view of right G1; (G) dorsal view of terminal article of right G1; (H) right G2. Scale bars: 5 mm (A, B); 10 mm (C); 2.5 mm (D) and 1 mm (E–H).

Figure 8. Newly described crabs from their natural habitats. (A) Ghatiana aurantiaca sp. nov., from laterite rocks in Phansad Wildlife Sanctuary, Raigad district; (B) Ghatiana hyacintha sp. nov., from bank of a stream in Radhanagari Wildlife Sanctuary, Kolhapur district; (C) Gubernatoriana triangulus sp. nov., from bank of a stream in Tahmini Ghat, Pune district.