Sinobatis

Last, Peter R. & Séret, Bernard, 2008, Three new legskates of the genus Sinobatis (Rajoidei: Anacanthobatidae) from the Indo – West Pacific, Zootaxa 1671, pp. 33-58 : 57

Key to Sinobatis of the Indo-West Pacific

1a. Ventral surface uniformly white, pinkish or translucent, lacking dark pigment.......................................... 2

1b. Ventral surface brownish, bluish or with large pale and dark areas, not uniformly pale............................. 3

2a. Tail with flattened, bulbous tip, width 1.3–2.2 times width at midlength; usually more than 22 rows of teeth in upper jaw; teeth in adult males with long conical cusps; pectoral-fin radials 66–71 ...................... ............................................ Sinobatis bulbicauda sp. nov. (northwestern Australia and eastern Indonesia)

2b. Tail filamentous, not bulbous near tip, width 0.7–1.1 times width at midlength; 22 or fewer rows of teeth in upper jaw; teeth in adult males with short cusps; pectoral-fin radials 71–75............................................ .................................................................................... Sinobatis filicauda sp. nov. (northeastern Australia)

3a. Dorsal surface of disc whitish or greyish, often paler than ventral surface; paler anteriorly than posteriorly on ventral surface; adults smaller than 25 cm disc width ....... Sinobatis borneensis (western North Pacific)

3b. Both dorsal and ventral surfaces of disc dark brown or bluish (except where skin removed); large species, reaching maturity above 30 cm disc width .................................................................................................. 4

4a. Dark brown above, usually blackish around eye and spiracles; interpelvic distance more than 2.5 times width of anterior pelvic-fin lobe at its base; ventral head length 32–34% TL; interspiracular pores indistinct ..................................................................................... Sinobatis melanosoma (western North Pacific)

4b. Greyish blue above, not significantly darker around eye and spiracles; interpelvic distance less than 2.5 times width of anterior pelvic-fin lobe at its base; ventral head length 38–42% TL; interspiracular pores obvious ....................................................................... Sinobatis caerulea sp. nov. (northwestern Australia)