Broad Stingray - Description

Description

The broad stingray has a diamond-shaped pectoral fin disc a fourth wider than long, with nearly straight leading margins that converge at an obtuse angle, and curved trailing margins. The tip of the snout is rounded and protrudes past the disc. The mouth is arched and contains 5–6 papillae on the floor, two of which are in front of the others. The pelvic fins are short and rounded. The whip-like tail is twice the length of the disc or more, and bears a serrated stinging spine on the upper surface near the tail base. There is a long, narrow fin fold beneath the tail, which eventually becomes a keel that runs all the way to the tail tip.

Larger rays have three large, elongated tubercles in the middle of the back; the tail is roughened by small dermal denticles, along with an irregular row of conical tubercles on each side and several large, flattened tubercles in front of the spine. This species is plain olive to brown above and white below. Though rarely found so far west, the similar-looking diamond stingray (D. dipterura) is the only other nearshore stingray that occurs off Hawaii; it can be distinguished from this species by its tail, which is shorter and has both upper and lower fin folds. The broad stingray can reach 1.5 m (5 ft) across and 56 kg (120 lb) in weight, though few exceed 1 m (3 ft) across.