Biogeographic aspects of ichthyofauna members from Central America

Abstract

Fish represent the largest group within vertebrates and present a wide distribution in fresh and saltwater environments, with freshwater species comprising 40% of the total number of species. A third of the ichthyofauna is found in the neotropical region (South and Central Americas) and comprises orders such as characiformes, siluriformes and Gymnotiformes as well a few osteoglossides, nandids and ciprinodontiforms. This large percentage of species, as well as its diversity makes the neotropical a region of great interest. The geologic events that molded the Center-American continent created interest scenarios of dispersion and origin of its endemic fi sh species from an original South American stock. This historic data is supported buy phylogeographic research, especially in Astyanax and Rhamdia. A proper evaluation of genetic variability and an understanding of evolutionary history are undisputable valuable tools for accessing general biodiversity providing solid background for conservation programs. The article is a review about the data concerning the subject.