This award will support Professor Jamie Thomerson of Southern Illinois University at Edwardsville in collaboration with Professor Donald Taphorn of the Universidad Nacional Experimental de los Llanos Occidentales in Guanare, Venezuela. The investigators intend to clarify the taxonomy, distribution, and natural history of Venezuelan rivulids. Members of a large Neotropical freshwater fish family the Rivulidae, rivulids, live in marginal habitats. Study of their distribution will provide tests for zoogeographic hypotheses based on other fish groups. While they are relatively well understood in terms of higher phylogenetic relationships, the taxonomy of the non-annual Rivulus species is muddled and inadequate study material is available. The PI's will concentrate their collecting on habitats where rivulids live. Many known localities are in areas undergoing rapid environmental modification. Live material will be collected for aquarium observation and hybridization studies. This study will: (1) increase our knowledge of diversity and distribution of Venezuelan rivulids; (2) clarify taxonomic and systematic problems in the difficult genus Rivulus; and (3) dramatically increase the amount of Venezuelan fish material available for study.
