''Heliotrygon gomesi'', the Gomes's round ray or China ray, is a

species In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of the appropriate s ...

of freshwater stingray native to the western

Amazon basin The Amazon basin is the part of South America drained by the Amazon River and its tributaries. The Amazon drainage basin covers an area of about , or about 35.5 percent of the South American continent. It is located in the countries of Bolivi ...

in South America, specifically

Brazil Brazil ( pt, Brasil; ), officially the Federative Republic of Brazil (Portuguese: ), is the largest country in both South America and Latin America. At and with over 217 million people, Brazil is the world's fifth-largest country by area ...

.de Carvalho, M.R. and N.R. Lovejoy, 2011. Morphology and phylogenetic relationships of a remarkable new genus and two new species of Neotropical freshwater stingrays from the Amazon basin (Chondrichthyes: Potamotrygonidae). Zootaxa 2776:13-48. It is the

type species In zoological nomenclature, a type species (''species typica'') is the species name with which the name of a genus or subgenus is considered to be permanently taxonomically associated, i.e., the species that contains the biological type specimen ...

of its

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In the hierarchy of biological classification, genus com ...

. It spends the day in deep river channels, but moves closer to the shore at night to feed.

Taxonomy

''H. gomesi'' was first discovered in Rio Jamari, Brazil, and described by Marcelo Rodrigues de Carvalho and Nathan R. Lovejoy in 2011. The genus name, ''

Heliotrygon The round rays (''Heliotrygon'') is a genus of freshwater stingrays in the family Potamotrygonidae. The genus is endemic to the Amazon basin in South America. Despite being discovered decades earlier, the genus was only scientifically described ...

,'' is derived from the Greek word 'helios,'' meaning sun, and refers to the ray's circular body that radiates outward. This species is named ''gomesi'' in honor of Ulisses L. Gomes and his pioneering research on

elasmobranchs Elasmobranchii () is a Class (biology), subclass of Chondrichthyes or cartilaginous fish, including sharks (superorder Selachii), Batoidea, rays, skate (fish), skates, and sawfish (superorder Batoidea). Members of this subclass are characteris ...

. Gomes' round ray is a member of the family Potamotrygonidae. Potamotrygonids are unique among living ray families in that they have diversified in the South American freshwater environment.

Description

This ray has an extremely circular body and reaches a disc width up to . The eyes of ''H. gomesi'' are very small and unprotruding. It is uniform gray to light brown above and it lacks any distinctive patterns. In addition to the lack of pattern, this species differs from '' H. rosai'' by showing a slender tail width at its base, a slightly larger preorbital

snout A snout is the protruding portion of an animal's face, consisting of its nose, mouth, and jaw. In many animals, the structure is called a muzzle, rostrum, or proboscis. The wet furless surface around the nostrils of the nose of many mammals is c ...

length, and a proportionally smaller pelvic inner length. It shows angular cartilages. Both species of ''

'' have greatly reduced caudal stings, rendering them virtually harmless.

References

External links

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FishBase
Potamotrygonidae Freshwater fish of Brazil Freshwater fish of Peru Fish of the Amazon basin Fish described in 2011 {{Chondrichthyes-stub

Taxonomy

Description

References

Further reading

External links