A new species of killifish has been described from the Guyana Shield in South America.
Rivulus sape was discovered in the Rio Paragua, part of the Rio Caroni drainage in the Guyana Shield in Venezuela, and has just been named by Oscar Lasso-Alcala, Donald Taphorn, Carlos Lasso and Oscar Leon-Mata in a paper in the systematics journal Zootaxa.
The fish is a member of the killifish family Rivulidae and is believed to be a small (less than 5cm/2") species with a non-annual lifestyle.
The authors state that Rivulus sape can be distinguished from other Rivulus by the presence of short dorsal, anal and pelvic fins. Adult males have a truncate caudal fin with black upper and lower borders, as well as an iridescent blue oval spot on the flanks, just above the pectorals.
Unlike some other Rivulus, both adults and juveniles lack an ocellus spot at the dorsal junction of the caudal peduncle and caudal fin.
For more details on the new killifish see the paper: Lasso-Alcala OM, Taphorn DC, Lasso CA and O Leon-Mata (2006) - Rivulus sape, a new species of killifish (Cyprinodontiformes: Rivulidae) from the Paragua River system, Caroni River drainage, Guyana Shield, Venezuela. Zootaxa, 1275: 21-29 (2006).