Bluntnose Stingray

The bluntnose stingray has a diamond-shaped pectoral fin disc about a sixth wider than long, with broadly rounded outer corners. The leading margins of the disc are nearly straight and converge at the tip of the snout at up to a 130° angle; the anterior disc shape distinguishes this species from the similar Atlantic stingray (D. sabina), which has a longer, more acute snout. The mouth is curved, with a central projection on the upper jaw that fits into an indentation on the lower jaw. There is a row of five papillae across the floor of the mouth, with the outermost pair smaller and set apart from the others. There are 36–50 upper tooth rows; the teeth have quadrangular bases and are arranged with a quincunx pattern into flattened surfaces. The tooth crowns are rounded in females and juveniles, while those of males in breeding condition are triangular and pointed.

The bluntnose stingray is found in the western Atlantic Ocean, from Long Island, New York southward through the Florida Keys, the northern Gulf of Mexico, and the Greater and Lesser Antilles; on rare occasions it is found as far north as Massachusetts, as far south as Venezuela, and as far west as Mexico. It is absent from the southern Gulf of Mexico and the Caribbean coast of Central America. Reports of this species from off Brazil and Argentina likely represent misidentifications of the groovebelly stingray (D. hypostigma).

The bluntnose stingray has generally nocturnal habits and spends much of the day buried in the substrate. It has been known to follow the rising tide to forage in water barely deep enough to cover its body. This species preys upon small invertebrates, including crustaceans, annelid worms, and bivalve and gastropod molluscs, and bony fishes. It mainly targets benthic and burrowing organisms, but also opportunistically takes free-swimming prey. In Delaware Bay, this species feeds predominantly on the sand shrimp Crangon septemspinosa and the blood worm Glycera dibranchiata, and its overall dietary composition is virtually identical to that of the roughtail stingray (Bathytoshia centroura), with which it shares the bay. The bluntnose stingray is preyed upon by larger fishes such as the bull shark (Carcharhinus leucas).

The bluntnose stingray is not aggressive, though it will defend itself if stepped on or otherwise incited. Its tail spine can inflict an excruciating injury, and can easily pierce leather or rubber footwear. The paralytic venom delivered may have potentially life-threatening effects on those with heart or respiratory problems, and is the subject of biomedical and neurobiological research. This species is popular with ecotourist divers. Abundant and widespread, the bluntnose stingray is caught incidentally by commercial trawl and gillnet fisheries operating in nearshore U.S. waters; these activities are not a threat to its population, as most captured rays are released alive. The impact of fishing in the southern parts of its range is uncertain, but is unlikely to significantly affect the species as a whole as these activities occur outside its centers of distribution.