The round ribbontail ray, blotched fantail ray, marble ray, or marbled ray (Taeniurops meyeni) is a species of stingray in the family Dasyatidae, found throughout the nearshore waters of the tropical Indo-Pacific, as well as off islands in the eastern Pacific. It is a bottom-dwelling inhabitant of lagoons, estuaries, and reefs, generally at a depth of 20–60 m (66–197 ft). Reaching 1.8 m (5.9 ft) across, this large ray is characterized by a thick, rounded pectoral fin disc covered by small tubercles on top, and a relatively short tail bearing a deep ventral fin fold. In addition, it has a variable but distinctive light and dark mottled pattern on its upper surface, and a black tail.
Generally nocturnal, the round ribbontail ray can be solitary or gregarious, and is an active predator of small, benthic molluscs, crustaceans, and bony fishes. It is aplacental viviparous, with the embryos sustained by yolk, and later histotroph ("uterine milk") secreted by the mother; up to seven pups are born at a time. Although not aggressive, if provoked the round ribbontail ray will defend itself with its venomous tail spine, and it has been responsible for at least one fatality. It is valued by ecotourist divers and recreational anglers. This slow-reproducing species is threatened by commercial fishing, both targeted and bycatch, and habitat degradation across much of its range. As a result, the International Union for Conservation of Nature (IUCN) has assessed it as Vulnerable.
