Monday, July 11, 2016

[Ichthyology • 2016] Hypselobarbus keralaensis • A New Species of Hypselobarbus (Cypriniformes: Cyprinidae) from Kerala region of Western Ghats, peninsular India


Hypselobarbus keralaensis 
Arunachalam, Chinnaraja & Mayden, 2016

Abstract

Hypselobarbus kurali (Menon & Rema Devi, 1995) consists of multiple species with similarity in the colour pattern of the tip of their caudal fins being orange and black. This complex of species possesses two pairs of barbels. Inspection of collections of H. kurali from the senior author’s samples from various streams/rivers of Western Ghats covering the Indian states of Tamil Nadu, Kerala and Karnataka revealed that an additional species has gone unrecognized. This new species, Hypselobarbus keralaensis, is diagnosed from its likely closest relative H. kurali by having fewer transverse breast scale rows (16 vs. 21-23) and fewer pre-anal scale rows (38-39 vs. 43-46).

Keywords: Cyprinidae, Hypselobarbus keralaensis sp. n, Taxonomy.


Fig.1. Hypselobarbus keralaensis Arunachalam, Chinnaraja & Mayden, 2016
(A) Hypselobarbus keralaensis sp. n. MSUMNH 95, Holotype, 176.65 mm SL, Thodaiyar stream, Karamana River basin, collected by M. Arunachalam and team, 10 November, 2001, (B) Hypselobarbus keralaensis sp. n. showing the anal fin structure and (C) gill-raker of Hypselobarbus keralaensis sp. n. 

Diagnosis: Hypselobarbus keralaensis sp. n. is distinguished from H. curmuca by two pairs of barbels (vs. one pair), fewer upper transverse scale rows (8.5 vs. 9.5-10), fewer circumferential scale rows (32-33 vs. 39-40), fewer circumpeduncular scale rows (18 vs. 20-21), more transverse breast scale rows (16 vs. 10-11), a shorter upper jaw length (26.31-31.51 vs. 38.85-43.05 %HL) and longer prenasal length (33.60-44.58 vs.26.57-31.48 %HL). It is distinguished from H. kolus in having two pairs of barbels (vs. one pair), fewer upper transverse scale rows (8.5 vs. 9.5-10), fewer lower transverse scale rows (6.5 vs. 7.5-9), fewer circumpeduncular scale rows (18 vs. 20-21), more transverse breast scale rows (16 vs. 12-14), longer snout (46.51-53.89 vs. 34.3-42.76 %HL), longer pre-nasal length (33.60- 44.58 vs. 22.61-33.18 %HL) and presence of orange and black on caudal tip (vs. absence of color pattern). It is distinguished from H. dubius in having a weaker dorsal spine (vs. strong), fewer lateral lines scale rows (41 vs. 42-45) and more transverse breast scale rows (16 vs. 9-11). The species is distinguished from H. micropogon in having a weaker dorsal spine (vs. strong), more transverse breast scale rows (16 vs. 8- 12), and more circumferential scale rows (32-33 vs. 26-29). It is distinguished from H. nilgiriensis in having a weaker dorsal spine (vs. strong), fewer pre anal scale rows (38-39 vs. 41-45) and fewer circumferential scale rows (32-33 vs. 34-35). It is distinguished from H. periyarensis in having fewer lateral line scale rows (41 vs. 43-44), fewer predorsal scale rows (13-14 vs. 17-18), more transverse breast scale rows (16 vs. 10-13), and the morphometric features of having a shorter distance between occiput and dorsal fin origin (23.74-25.13 vs. 30.12-34.75 %SL), shorter dorsal origin to pectoral insertion (25.54-27.63 vs. 33.25-37.45 %SL) and longer snout (46.51-53.89 vs. 35.45-38.34 %HL).


Coloration: Dorsal half of body greyish, lighter on the sides and venter; deep black bar behind opening of operculum. Base of the scales above and below the lateral line with dark spots. Tips of caudal tinged black (Figs.1 and 2). 

Distribution: This species is currently known from three rivers in Kerala. 

Etymology: The new species is named after the state of Kerala as specimens were collected from south and north Kerala.


Muthukumarasamy ARUNACHALAM, Sivadoss CHINNARAJA AND Richard Lee MAYDEN. 2016. Description of A New Species of Hypselobarbus from Kerala region of Western Ghats, peninsular India (Cypriniformes: Cyprinidae). Iranian Journal of Ichthyology. 3(2): 73–81. http://IJIchthyol.org/index.php/iji/article/view/3-2-1

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