Brevitrygon, Last, Peter R., Naylor, Gavin J. P. & Manjaji-Matsumoto, B. Mabel, 2016

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 : 359-360

Genus Brevitrygon gen. nov.

Type species Dasyatis javaensis Last & White, 2013 ; newly proposed.

Definition. Small dasyatids (adults typically to 23–32 cm DW) characterised by the following: strongly depressed, oval to suboval disc with pectoral-fin apex broadly rounded; snout acutely angular and elongate (1.9–3.6 times combined orbit and spiracle length); eye small and protruding slightly; nasal curtain broadly skirt shaped; mouth medium-sized with 2–4 oral papillae; tail rather short and semi-rigid or filamentous distally (length 1–2.2 times DW), its base broad and strongly or weakly depressed; pelvic fins small to medium-sized, protruding slightly beyond disc; dorsal fold and ventral folds absent (low ridges present in B. walga ); caudal sting close to tail base (distance from pectoral-fin insertion to caudal-sting base 1.4–2 times interspiracular width); denticle band well developed with edge sharply defined, skin on rest of disc naked; median thorns on disc weak, those on tail larger when present; no scapular thorns and rarely denticles on posterior tail; dorsal coloration plain; ventral surface white, disc margin dark edged; posterior tail plain or with pale lateral stripe; marine, Indo– West Pacific.

Species. B. heterura (Bleeker, 1852) , B. imbricata (Bloch & Schneider, 1801) , B. javaensis (Last & White, 2013) , and B. walga (Müller & Henle, 1841) .

Etymology. Combination of the Latin brevi (short) and Greek trygon (stingray) reflects the short and semirigid tail of all members of the genus.

Remarks. Newly erected, morphologically conservative genus with four small species previously placed in Himantura . The taxonomy of this group is very confused and is the subject of a generic review in progress (PL, unpublished). Brevitrygon heterura (Bleeker, 1852) is the correct name of a common Western Pacific species, misidentified as Himantura (= Brevitrygon ) walga (Müller & Henle, 1841) . Brevitrygon walga and B. imbricata (Bloch & Schneider, 1801) are both confined to the Indian Ocean.