Genus Dasyatis Rafinesque, 1810

Dasyatis Rafinesque, 1810:16 . Type species Dasyatis ujo Rafinesque, 1810 (= Raja pastinaca Linnaeus, 1758); designated by monotypy.

Definition. Small to medium-sized dasyatids (adults to 38–84 cm DW) characterised by the following: robust, rhombic disc with pectoral-fin apex narrowly rounded to angular; snout broadly angular and short (1.1–1.5 times combined orbit and spiracle length); eye medium-sized to large and protruding slightly; nasal curtain broadly skirtshaped; mouth medium-sized, with 3–7 oral papillae (3 centrally); tail firm, somewhat filamentous distally (length 1.2–2.3 times DW), its base broad to very broad and depressed; pelvic fins medium-sized to large, protruding well beyond disc; dorsal fold variably developed, low or reduced to form a ridge; ventral fold low (better developed in D. pastinaca) with a short to long base; caudal sting typically forward on tail (distance from pectoral-fin insertion to caudal-sting base 1.8–3 times interspiracular width); no median thorns on disc and denticle band absent; skin typically smooth, except in largest adults which may have sparse coverage of denticles and sometimes welldeveloped thorns on anterior tail; scapular thorns absent; tail smooth or prickly; dorsal coloration plain or with prominent pattern; ventral surface white, disc margin sometimes dark; tail plain, black distally; marine, Atlantic and South-West Indian Ocean.

Species. D. chrysonota (Smith, 1828), D. hypostigma Santos & Carvalho, 2004, D. marmorata (Steindachner, 1892), D. pastinaca (Linnaeus, 1758), and D. tortonesei Capapé, 1977 .

Remarks. The polyphyletic genus Dasyatis, once thought to consist of 36 species with widespread distributions in tropical and temperate seas, now applies to a monophyletic group of five small to medium-sized species found in the Atlantic (including the Mediterranean Sea) and SW Indian Ocean (see Fig. 1). Molecular data supports the non-conspecificity of similar blue-marbled forms, D. chrysonota and D. marmorata .