Bathytoshia Whitley, 1933

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 : 354

Genus Bathytoshia Whitley, 1933

Bathytoshia Whitley, 1933:61 . Type species Dasyatis thetidis Ogilby, 1899 ; by original designation.

Definition. Gigantic dasyatids (adults to 210–260 cm DW) characterised by the following: robust, rhombic disc with pectoral-fin apex narrowly angular; snout obtuse and moderately elongate (1.5–2.5 times combined orbit and spiracle length); eye small and protruding slightly; nasal curtain broadly skirt shaped; mouth rather broad, with 3–7 oral papillae; tail firm and short to moderately elongate (length <1–2 times DW), its base broad to very broad and depressed; pelvic fins medium-sized, protruding slightly to greatly beyond disc; dorsal fold absent or forming a low ridge; ventral fold low with a short or long base; caudal sting not posterior on tail (distance from pectoral-fin insertion to caudal-sting base 2.2–3 times interspiracular width); skin smooth or rough and denticle band absent; median thorns absent or in a row extending along disc and onto tail, scapular thorns small or absent; tail spiny with bucklers and tubercles on dorsal midline of adults; dorsal colour largely plain; ventral surface white, disc margin sometimes dark; tail plain, usually black distally; marine, Atlantic and Indo– West Pacific.

Species. B. brevicaudata (Hutton, 1875) , B. centroura (Mitchill, 1815) , and B. lata (Garman, 1880) .

Remarks. Former junior synonym of Dasyatis ( Kottelat, 2013) includes a small group of very large and widely distributed stingrays. Molecular data (G. Naylor, unpubl.) provides evidence that species complexes (A) Bathytoshia (as Dasyatis ) brevicaudata and D. matsubarai Miyosi, 1939 , and (B) Bathytoshia (as Dasyatis ) lata , D. thetidis Ogilby, 1899 , D. ushiei ( Jordan & Hubbs, 1925), and eastern Atlantic stingrays identified as D. centroura (e.g. McEachran & Capapé, 1984), are populations of just two species (i.e. D. brevicaudata and D. lata ). A western Atlantic species, Bathytoshia centroura (Mitchill, 1815) , is not conspecific with Bathytoshia of the eastern Atlantic. The pelagic stingray Pteroplatytrygon violacea (Bonaparte, 1832) , which clusters with these species ( Fig. 1), is morphologically distinct from all other members of the family.