Pastinachus Rüppell, 1829

Last, Peter R., Naylor, Gavin J. P. & Manjaji-Matsumoto, B. Mabel, 2016, A revised classification of the family Dasyatidae (Chondrichthyes: Myliobatiformes) based on new morphological and molecular insights, Zootaxa 4139 (3), pp. 345-368 : 364

Genus Pastinachus Rüppell, 1829

Pastinachus (subgenus of Trigon ) Rüppell, 1829:51. Type species Raja sephen Forsskål, 1775 ; by subsequent designation.

Definition. Small to very large dasyatids (adults to 43–200 cm DW or more) characterised by the following: depressed to robust, rhombic disc with pectoral-fin apex angular to narrowly rounded; snout obtuse or broadly angular, and short to medium length (1.6–2.4 times combined orbit and spiracle length); eye small and protruding slightly; nasal curtain distinctly bilobed; mouth narrow to medium-width with 5 oral papillae; tail firm and long to very long (length 1.8–3.2 times DW), its base broad to very broad and noticeably depressed; pelvic fins large, protruding slightly beyond disc; dorsal fold absent; ventral fold deep to very deep with a long base; caudal sting positioned posteriorly on tail (distance from pectoral-fin insertion to caudal-sting base 3.5–4.6 times interspiracular width); denticles on dorsal surface of disc patchy, denticle band well developed, but with diffuse edges; 1–3 variably developed, pearl or heart-shaped mid-scapular thorns, no other thorns on disc; tail prickly but lacking enlarged thorns (except in Pastinachus stellurostris ); plain coloured dorsally, ventrally white, disc margin often dark; marine/estuarine, Indo– West Pacific.

Species. P. at er (Macleay, 1883), P. gracilicaudus Last & Manjaji-Matsumoto, 2010 , P. sephen (Forsskål, 1775) , P. solocirostris Last, Manjaji & Yearsley, 2005 , and P. stellurostris Last, Fahmi & Naylor, 2010 .

Remarks. Until recently, thought to consist of a single, widespread Indo–Pacific species, Pastinachus sephen ( Last & Stevens, 1994) . Recent research (confirmed by molecular data) has demonstrated that the group is not monotypic, and P. s e ph e n is restricted to the northwestern Indian Ocean and another large stingray (P. a t e r) is more widespread.