himantura

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Giant freshwater stingray (Himantura polylepis)

The giant freshwater stingray is a species of stingray in the family Dasyatidae. It is found in large rivers and estuaries in Indochina and Borneo, though historically it may have been more widely distributed in South and Southeast Asia. One of the largest freshwater fish in the world, this species grows upwards of 1.9 m across and may reach 600 kg in weight. Bottom-dwelling in nature, the giant freshwater stingray inhabits sandy or muddy areas and preys on small fishes and invertebrates. Females give live birth to litters of one to four pups, which are sustained to term by maternally produced histotroph (“uterine milk”). This species faces heavy fishing pressure for meat, recreation, and aquarium display, as well as extensive habitat degradation and fragmentation. These forces have resulted in substantial population declines in at least central Thailand and Cambodia. As a result, the International Union for Conservation of Nature (IUCN) has assessed the giant freshwater stingray as Endangered.

photo credits: fishing videos, Barry Rogge, Amelia Guo

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Leopard whipray - Himantura leoparda

Encountered in the Indo-Pacific from South Africa to Australia, the leopard whipray has a striking pattern of dark brown rings on its dorsal side that gave it its name. Like all species in the Himantura genus, known as the whiprays, it has a very long, thin tail that lacks a dorsal or caudal fin and can measure more than three times the length of its disc. Adults can reach approximately 5.9ft in width and a total length of about 13ft with an intact tail. Due to confusion with the closely related honeycomb and reticulate whiprays, the leopard whipray is not well known. It is heavily fished in parts of Indonesia for its meat and possibly other parts using bottom trawls, tangle nets, and longlines, and has not been classified by the IUCN at this time.