Origin of the characid fish genus Bramocharax and a description of a second, more primitive, species in Guatemala. American Museum novitates ; no. 2500

21 p. : ill., maps ; 24 cm.Includes bibliographical references (p. 21)."A new species of the characid fish genus Bramocharax is described from a karst region along the northern foothills of the Sierra de Chamá in Guatemala. The region is characterized by sinks and caverns into which streams of various sizes disappear. The points of emergence or hydrographic relationships of these streams are not always evident, but the ichthyofaunal evidence presented helps to tie some of them to two of the major tributaries of the Río Usumacinta system. The phyletic relationships of the three presently known forms of Bramocharax (the species being described here and the two subspecies of bransfordi) are analyzed. The zoogeographic inferences drawn from the proposed phylogeny are that the genus Bramocharax arose in the Río Usumacinta system and then spread southward to the Río San Juan system of Nicaragua and Costa Rica. The populations of Bramocharax inhabiting lakes Nicaragua and Managua are identified as historically the most recently established"--P. [1]