Five new species of freshwater crabs of the genera Ghatiana Pati & Sharma, 2014 and Sahyadriana Pati & Thackeray, 2018 from India (Decapoda: Brachyura: Gecarcinucidae)

ABSTRACT We recognize two new species of Ghatiana Pati & Sharma, 2014, and three new species of Sahyadriana Pati & Thackeray, 2018, from the Western Ghats of India. Ghatiana durrelli n. sp. is characterized mainly by the proportionately narrower adult carapace, the relatively broader male pleonal somite 6, and the relatively stouter terminal segment of the male first gonopod. Ghatiana rouxi n. sp. is differentiated from congeners by its proportionately narrower adult carapace with the gently convex lateral margins. Sahyadriana inopinata n. sp. is characterized by a suite of characters that includes the visible epibranchial tooth, the relatively slenderer and longer terminal segment of the male first gonopod, and the subovate and relatively smaller adult vulva that is positioned a clear distance from the suture between thoracic sternites 5 and 6. Sahyadriana keshari n. sp. differs from the allied S. waghi (Pati in Pati, Thackeray & Khaire, 2016) by the relatively stouter terminal segment of the male first gonopod, and the relatively larger adult vulva, which is positioned close to the suture between thoracic sternites 5 and 6. Sahyadriana tamhini n. sp. most resembles S. alcocki (Pati in Pati, Thackeray & Khaire, 2016) but can be differentiated by its relatively longer, distally distinctly narrow terminal segment and the sinuous inner margin of the subterminal segment of the male first gonopod, and the relatively closely positioned and larger adult vulvae. Ghatiana and Sahyadriana now include 10 species and 13 species, respectively. An updated key is provided for both genera.

Ghatiana and Sahyadriana are distinct from the known gecarcinucid genera of India by the absence of a flagellum on the exopod of the third maxilliped and the very short male second gonopod. Ghatiana can be diagnosed by its relatively narrow front, the presence of a flagellum on the exopod of the first and second maxillipeds, the relatively longer exopod of the third maxilliped, the relatively stouter male pleon, the relatively squarish male pleonal somite 6, the elongated male telson, and the relatively short and stout male first gonopod, whereas Sahyadriana is characterized mainly by the relatively shorter ambulatory legs, with densely setose dactylus and/ or propodus, the relatively longer male sternopleonal cavity that reaches beyond the imaginary line joining the bases of the third maxillipeds, and the short male telson (Pati & Thackeray 2018).
We recognize herein two new species of Ghatiana and three new species of Sahyadriana, based on the recent collections from the Western Ghats of Goa, Karnataka, and Maharashtra. An updated key is provided for both genera.

AbbreviAtions
etymoloGy. -The species name, derived from the Marathi language for orange coloured, refers to live colouration of the crab. The name is used as a Latin noun in apposition.
colour in life. -Carapace, chelipeds, and ambulatory legs all are completely orange in colour (Fig. 3E). The orange colour on the ventral side of the carapace, however, is relatively faint.
ecoloGicAl notes. -Sahyadriana keshari n. sp. dwells on the walls of high mountainous cliffs (1048 m above a.s.l.), which host ephemeral waterfalls. Crabs gather in large numbers during the daytime on these exposed walls between the downpour.
GeoGrAphicAl distribution. -Sahyadriana keshari n. sp. is currently known only from Bramhagiri, an isolated high mountain of the Western Ghats in Nashik district of Maharashtra state, India.
etymoloGy. -The species is named after the type locality, Tamhini Ghat, a hotspot for wildlife in Maharashtra that hosts rich biodiversity and many endemic species, including that of the freshwater crabs. The species name is used as a Latin noun in apposition.
colour in life. -The species shows colour variation. The carapace and ambulatory legs are generally saddle brown, with orange coloured chelipeds on the dorsal surface (Fig. 3F); the carapace and pereiopods are relatively paler ventrally. Some crabs have orange coloured carapace and chelipeds but brownish ambulatory legs dorsally (Fig. 3G). Some individuals are completely brown (Fig. 3H), with a paler ventral surface of the carapace. ecoloGicAl notes. -Sahyadriana tamhini n. sp. was found under cobblestones near the base of rainfed cascades in an elevated mountain (above 570 m altitude). Some individuals were also seen dwelling in the crevices of mountain cliffs. These crabs are very active during the monsoon season (June to September).
GeoGrAphicAl distribution. -Sahyadriana tamhini n. sp. is known only from the type locality (Tamhini Ghat) in the Western Ghats of Pune district, Maharashtra, India.