Dasyatis Rafinesque 1810

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.