TAXONOMY
Class: Potamotrygon henlei Elasmobranchii (Sharks and rays),
Order: Rajiformes (Skates and rays)
Family: Potamotrygonidae (River stingrays).

Genus/species: Potamotrygon leopoldi

2974039132_da5bb801a4_b

GENERAL CHARACTERISTICS: Width to 45 cm. Body greatly flattened and circular, composed principally of expanded pectoral fins. Tail is slender and longer than body, has venomous spine. Coloblack, white polka dots.

DISTRIBUTION/HABITAT: South America: Tocantins River basin. Freshwater, able to tolerate only a narrow range of salinities.

DIET IN THE WILD: DIET: Mostly benthic hard-shelled invertebrates, such as clams, mussels, and crustaceans. Also worms, insect larvae, and small fishes. Like most rays, flat teeth are used to grip and crush prey that is sucked into the ventral mouth. Note periscoping eyes which protrude from sand when buried.

REPRODUCTION: Ovoviviparous. Like all in the family, fetuses developing in the mother’s uterus first feed on their yolk sacs, after which filaments develop from the uterine wall and carry nutrients and remove wastes from the fetuses until they are fully developed.

CONSERVATION STATUS: A rare, poorly known river ray, possibly endemic to river drainages in Brazil where freshwater habitat degradation is occurring. Although this attractive freshwater ray enters the ornamental fish trade, life history and population data are lacking.

REMARKS: River Stingrays (Family Potamotrygonidae) spend much of the time buried in sand or mud with only their relatively large eyes protruding. This family is the only group of rays adapted exclusively to freshwater and is found only in Neotropical river basins. Potent venomous spine, used defensively, makes this a dangerous species. Like all stingrays, sheds spine periodically as the individual grows.

Flooded Amazon

flickr http://www.flickr.com/photos/cas_docents/sets/72157608376694453/

WordPress Shortlink http://wp.me/p1DZ4b-Ph