Sahyadriana keshari, Pati & Thackeray, 2021

Pati, Sameer K. & Thackeray, Tejas, 2021, Five new species of freshwater crabs of the genera Ghatiana Pati & Sharma, 2014 and Sahyadriana Pati & Thackeray, 2018 from India (Decapoda: Brachyura: Gecarcinucidae), Zoosystema 43 (26), pp. 627-647 : 639-642

publication ID	https://doi.org/ 10.5252/zoosystema2021v43a26
publication LSID	urn:lsid:zoobank.org:pub:24B254A2-36F7-4DA7-B5C8-9D0EE5DBA85B
DOI	https://doi.org/10.5281/zenodo.5600403
persistent identifier	https://treatment.plazi.org/id/548CA624-C80A-48BF-86D0-19F9B835609E
taxon LSID	lsid:zoobank.org:act:548CA624-C80A-48BF-86D0-19F9B835609E
treatment provided by	Felipe
scientific name	Sahyadriana keshari
status	sp. nov.

Treatment

Sahyadriana keshari View in CoL n. sp.

( Figs 3E View FIG ; 8 View FIG A-D; 9 View FIG A-H)

urn:lsid:zoobank.org:act:548CA624-C80A-48BF-86D0-19F9B835609E

TYPE MATERIAL. — Holotype. India • ♂ (CW 13.96 mm, CL 10.88 mm, CH 6.38 mm, FW 4.98 mm); Maharashtra: Nashik district: Bramhagiri, near Trimbak ; 19°54’46”N, 73°31’4”E; alt. 1048 m; 17.VIII.2017; Tejas Thackeray leg.; ZSI-WRC C.2007 . GoogleMaps

Paratypes. India • ♂ ( CW 13.97 mm, CL 11.02 mm, CH 6.24 mm, FW 5.06 mm), ♀ ( CW 15.92 mm, CL 12.16 mm, CH 6.35 mm, FW 5.74 mm); same data as for holotype; ZSI-WRC C.2008 GoogleMaps • 5 ♂ ( CW 12.44-14.18 mm, CL 9.55-11.01 mm, CH 5.58-7.16 mm, FW 4.46-4.94 mm), 5 ♀ ( CW 12.11-15.53 mm, CL 9.39-11.73 mm, CH 6.14-7.23 mm, FW 4.44-5.44 mm); same data as for holotype; ZSI-WRC C.2009 GoogleMaps .

TYPE LOCALITY. — India: Maharashtra: Nashik district: Bramhagiri, near Trimbak; 19°54’46”N, 73°31’4”E; alt. 1048 m.

DIAGNOSIS. — Carapace in adult slightly broader than long (CW/ CL = 1.3), moderately to strongly deep ( CH /CL = 0.5-0.7); epibranchial tooth visible as relative distinct notch; branchial regions inflated; epistome posterior margin with gently concave lateral lobes ( Fig. 8 View FIG A-C). Third maxilliped lacking flagellum on exopod ( Fig. 9A View FIG ). Chelipeds with pointed fingertips ( Figs 8A, D View FIG ; 9B View FIG ). Ambulatory legs with densely setose dactylus and propodus ( Fig. 8A, D View FIG ). Male sternopleonal cavity long, extending beyond imaginary line joining bases of third maxillipeds ( Figs 8D View FIG ; 9C View FIG ). Male pleon relatively broad, T-shaped; pleonal somite 5 with concave lateral margins; pleonal somite 6 subquadrate, broader than long, subequal in length to telson, lateral margins strongly convex ( Figs 8D View FIG ; 9C View FIG ). Male telson short ( Figs 8D View FIG ; 9C View FIG ). G1 distinctly stout, almost straight; terminal segment relatively slender, subcylindrical, distally gently curved inwards, relatively short, c. 0.4 times length of subterminal segment; subterminal segment distinctly stout, triangular, distally relatively broad, with convex inner margin ( Fig. 9D, E View FIG ). G2 very short, with very short distal segment ( Fig. 9F View FIG ). Female pleon in adult broadly subtriangular ( Fig. 9G View FIG ). Vulvae in adult positioned apart from each other (VD/SW = c. 0.4), each suborbicular in shape, relatively large, occupying c. 0.5 times length of S6, positioned close to S5/S6 ( Fig. 9H View FIG ).

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 View FIG ). 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. The new species is very likely to occur on the adjacent mountainous peak “Anjneri” of the same district because the second author (TT) once saw a dead crab of the species there.

REMARKS

The carapace of S. keshari n. sp. most resembles to that of S. waghi (Pati in Pati, Thackeray & Khaire, 2016) mainly due to the relatively distinct notch between the epibranchial tooth and the external orbital angle ( Fig. 8A, B View FIG ; see Pati et al. 2016: fig. 11A; Pati & Thackeray 2018: fig. 29A), the gently concave lateral lobes of the epistome posterior margin ( Fig. 8C View FIG ; see Pati et al. 2016: fig. 11B; Pati & Thackeray 2018: fig. 29B), and the pointed fingertips of the chelipeds ( Figs 8A, D View FIG ; 9B View FIG ; see Pati et al. 2016: fig. 11A, C, D; Pati & Thackeray 2018: fig. 29A, C). In the G1 structure, S. keshari n. sp. is most similar to S. waghi and S. triangulus because all have a distinctly stout G1, with the relatively slenderer, subcylindrical terminal segment ( Fig. 9D, E View FIG ; see Pati & Sharma 2014: fig. 7E-G; Pati et al. 2016: fig. 12A-C; Pati & Thackeray 2018: figs 28D, E, H; 29D-G, I-K).

Both S. keshari n. sp. and S. waghi can be differentiated from S. triangulus by the relatively distinct notch between the epibranchial tooth and the external orbital angle ( Fig. 8A, B View FIG ; see Pati et al. 2016: fig. 11A; Pati & Thackeray 2018: fig. 29A) (vs indistinct notch between the epibranchial tooth and the external orbital angle in S. triangulus ; see Pati & Sharma 2014: fig. 6A; Pati & Thackeray 2018: fig. 28A), the gently concave lateral lobes of the epistome posterior margin ( Fig. 8C View FIG ; see Pati et al. 2016: fig. 11B; Pati & Thackeray 2018: fig. 29B) (vs strongly concave lateral lobes of the epistome posterior margin in S. triangulus ; see Pati & Sharma 2014: fig. 6B; Pati & Thackeray 2018: fig. 28B), the relatively shorter G1 terminal segment, c. 0.4 times the length of the subterminal segment, with the gently inwardly curved distal portion ( Fig. 9D View FIG ; see Pati & Thackeray 2018: figs 29I-K) (vs relatively longer G1 terminal segment, c. 0.5 times the length of the subterminal segment, with the distinctly outwardly curved distal portion in S. triangulus ; see Pati & Sharma 2014: fig. 7E-G; Pati & Thackeray 2018: fig. 28D, E, H), and the convex inner margin of the G1 subterminal segment ( Fig. 9D, E View FIG ; see Pati et al. 2016: fig. 12A, B; Pati & Thackeray 2018: fig. 29D, F, I-K) (vs almost straight inner margin of the G1 subterminal segment in S. triangulus ; see Pati & Sharma 2014: fig. 7E, F; Pati & Thackeray 2018: fig. 28D, E, H). Sahyadriana keshari n. sp. can be further separated from S. waghi by the relatively stouter G1 terminal segment ( Fig. 9D View FIG ) (vs relatively slenderer G1 terminal segment; see Pati et al. 2016: fig. 12A; Pati & Thackeray 2018: fig. 29D, I-K), the relatively broader distal portion of the G1 subterminal segment ( Fig. 9D View FIG ) (vs relatively narrower distal portion of the G1 subterminal segment; see Pati et al. 2016: fig. 12A; Pati & Thackeray 2018: fig. 29D, I-K), and the relatively larger adult vulva that occupies c. 0.5 times the length of the S6 and is positioned close to S5/S6 ( Fig. 9H View FIG ) (vs relatively smaller adult vulva that occupies c. 0.4 times the length of the S6 and is positioned a clear distance from S5/S6; see Pati & Thackeray 2018: fig. 29M).