Urolophidae

Urolophidae
Crossback stingaree (Urolophus cruciatus)
Scientific classification
Domain:	Eukaryota
Kingdom:	Animalia
Phylum:	Chordata
Class:	Chondrichthyes
Subclass:	Elasmobranchii
Clade:	Batomorphi
Order:	Myliobatiformes
Family:	Urolophidae J. P. Müller & Henle, 1841
Genera
Spinilophus Trygonoptera Urolophus

The Urolophidae are a family of rays in the order Myliobatiformes, commonly known as stingarees or round stingrays. This family formerly included the genera Urobatis and Urotrygon of the Americas, which are presently recognized as forming their own family Urotrygonidae. Stingarees are found in the Indo-Pacific region, with the greatest diversity off Australia. They are sluggish, bottom-dwelling fish that have been recorded from shallow waters close to shore to deep waters over the upper continental slope. Measuring between 15 and 80 cm (5.9 and 31.5 in) long, these rays have oval to diamond-shaped pectoral fin discs and relatively short tails that terminate in leaf-shaped caudal fins, and may also have small dorsal fins and lateral skin folds. Most are smooth-skinned, and some have ornate dorsal color patterns.

Stingarees feed on or near the sea floor, consuming small invertebrates and occasionally bony fishes. They are aplacental viviparous, meaning their embryos emerge from eggs inside the uterus, and are sustained to term first by yolk and later by maternally produced histotroph ("uterine milk"). As far is known, the gestation period lasts around a year and litter sizes tend to be small. Stingarees have one or two relatively large, venomous stinging spines on their tail for defense, with which they can inflict a painful wound on humans. Generally, stingarees have no economic value. Some species form a substantial component of the bycatch of commercial trawl fisheries.