Distocyclus conirostris
Distocyclus is a monospecific genus of freshwater ray-finned fish belonging to the family Sternopygidae, the glass knifefishes. The only species in the genus is Distocyclus conirostris which is found in the deep waters of the Amazon basin, lower portions of the Potaro River and in major parts of the Rio Orinoco. They are typically found in flood basins, flooded forests, and main river channels. They have often been found gathering in small groups around vegetation, indicating a social nature. The fish has semi-translucent, glass-like pectoral and anal fins. The main body is a ground-like color with a lighter head. The largest currently recorded specimen measures.
Ecology
Distocyclus conirostris has a tapering, conical snout with the top and bottom jaws being equal in length. The mouth is located terminally. The eyes are located on either side of a bilaterally compressed, elongated body and are covered by a nictitating membrane. The snout contains a uniquely small nasal capsule for the family Sternopygidae. The mouth of Distocyclus conirostris contains a single row of teeth located on the anterior area of the dentary bone, a trait also unique to this species in comparison to the other members of the Sternopygidae.The fish is covered in cycloid scales and typically has 4 to 5 gills with 4 to 11 small gill rakers. The body lacks any dark bands running laterally down the body, something present in Japigny kirschbaum, another species of the Sternopygidae. The fish also typically has 13–14 precaudal vertebrae, differing significantly from the 20–26 precaudal vertebrae present in the Sternopygus genus.
Distocyclus goajira, a potential sister fish of Distocyclus conirostris, is currently a subject of debate in regards to its phylogenetic position and relationship within either the Distocyclus genus or the Sternopygidae family.