Austrolebias univentripinnis sp. nov. (Teleostei: Cyprinodontiformes: Rivulidae): a new annual killifish from the Mirim Lagoon basin, southern Brazil. Wilson J. E. M. Costa Morevy M. Cheffe Zootaxa 2005 1052 41 48 36CL 308056 urn:lsid:zoobank.org:act:AA9F26E7-8843-4CAD-8100-4C06857E5AA4 Rivulidae Austrolebias CoL Animalia Austrolebias Costa 1998:75 Cyprinodontiformes 42 Chordata genus  The genus Austrolebias Costacomprises a diversified clade of Cynolebiatini annual killifishes endemic to southern Brazil, Paraguay, northern Argentina and Uruguay (Costa, 1998, 2002). Its included species inhabit temporary pools characteristic of all river drainages in this region, including the Parana-Paraguay-UruguayRiver system and the Patos-Mirim lagunar system. The latter system is located near the coast of southern Brazil and northeastern Uruguay, and is home to ten species of Austrolebias: A. adloffi (Ahl), A. arachan Loureiro, Azpelicueta & Garcia, A. charrua Costa & Cheffe, A. cyaneus (Amato), A. gymnoventris (Amato), A. luteoflammulatus (Vaz-Ferreira, Sierra & Scaglia), A. jaegari Costa & Cheffe, A. minuano Costa & Cheffe, A. nigrofasciatus Costa & Cheffe, and A. viarius (Vaz-Ferreira, Sierra & Scaglia)(Costa & Cheffe, 2001, 2002; Costa, 2003; Loureiro et al., 2004). A new species from the JaguaraoRiver drainage, which is tributary to the Mirim Lagoon, having apomorphic features such as triangular anal fin in females, pelvic-fin bases medially fused, and urogenital papilla attached to anal fin in males is herein described.