Diagnosis |
Diagnosis: Dasyatis margaritella is the smallest dasyatid in West Africa (Ref. 26277). It is most similar to Dasyatis margarita, which is larger and has a larger pearl spine, and more numerous pectoral radials, 133-135 vs. 116-127 in D. margaritella (Ref. 26277). It is also similar to D. garouaensis, which has a much flatter disc and a longer snout (Ref. 26277).
Description: Disc rounded-oval, width and length roughly equal, with broadly rounded corners, and moderately flat; its medial lobe broad-based and exserted, its anterior margin concave; disc depth 11.0-15.5% of disc width, disc width 0.9-1.1 times disc length (Ref. 26277, 81259, 81625). Middle third of disc covered with small heart-shaped or circular flat denticles; no enlarged thorns on disc or tail (Ref. 26277). Snout moderately long, acutely pointed, giving the body a slightly pentagonal appearance (Ref. 26277, 81259). Eyes and spiracles about equal size; nasal curtain with fringed posterior margin and groove extending from nasal flap to mouth corners (Ref. 81625). Upper jaw slightly undulate, with a great number of tooth rows: 24-41/34-50; 5 fleshy papillae on mouth floor (Ref. 7397, 81259, 81625). Pelvic fins projecting only slightly from posterior disc margin (Ref. 81625). Total number of pectoral radials 113-127 (Ref. 7397, 81259, 81625). Tail long and slender, tapering from base, with numerous sharp denticles posterior to stings; tail base about one-half of interorbital length, depressed in cross-section, horizontally oval; dorsal tail-fold reduced to a low keel posterior to caudal stings, but ventral tail-fold moderately high (Ref. 81625). Pearl spine always present and moderately large (Ref. 26277).
Colouration: Disc and pelvic fins gray-brown above, without spots or prominent markings, white below and without a marginal dark band (Ref. 26277, 81625). |