New stingray genus discovered in the Amazon
12/03/2011 11:24:04
Heliotrygon gomesi, adult female, in dorsal view. Photo taken by Ken Jones.
Two new species discovered in the AmazonMarch 2011. A biologist from the University of Toronto has discovered a new kind of tropical freshwater stingray. Dr Nathan Lovejoy's 10 years of research with his collaborator, Marcelo Rodrigues de Carvalho of the University of Sao Paolo, confirmed the first new genus of stingrays from the Amazon region in more than two decades.
"It took a considerable amount of time to collect enough specimens to describe the species," says Lovejoy, who sometimes had to compete with international fish exporters for the bigger examples. "They are uncommon fishes and therefore difficult to obtain."
Pancake-shaped
Their work in the Upper Amazon confirmed the new genus, Heliotrygon, and the two new species, Heliotrygon gomesi and Heliotrygon rosai. Both are known for their large size, pancake-like appearance, having a distinct pattern of lateral line canals on the ventral surface and a degenerate spine.
Most of Lovejoy and Carvalho's specimens came from the Rio Nanay River, near Iquitos in Peru. Their discovery brings the total number of Neotropical stingray genera to four. Before their study, the last new genus of stingrays of Amazon was described in 1987.
More to be discovered
"The most important thing this discovery tells us is that there are quite likely to be other large fishes in the Amazon yet to be discovered and described," says Lovejoy. "Our understanding of the biodiversity of this region is not complete, by any stretch of the imagination."
Dr Nathan Lovejoy, an associate professor of ecology and evolutionary biology at UTSC, is co-author on a new study detailing the discovery of a new genus and two new species of stingrays found in the upper Amazon.
Lovejoy's paper was recently published in the scientific journal Zootaxa.

Radiograph (x-ray) in dorsoventral view, depicting morphological aspects of Heliotrygon gomesi, preadult male. Taken by Ken Jones, UTSC Staff Photographer. | 
Heliotrygon with two smaller Potamotrygon specimens. Photo by David Webber/www.belowwater.com |
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