Rivulus uakti and R. amanapira described

Rivulus uakti sp. n. and R. amanapira sp. n. (Teleostei: Cyprinodontiformes: Rivulidae): two new species from the upper Rio Negro, Brazilian Amazon W.J.E.M. COSTA (Brazil)
Zootaxa 465: 1-12 (16 March 2004) 6 plates; 13 references

Abstract and excerpt here on Zootaxa. Full artucle here (subscription required).