SYSTEMATICS OF THE STICK CATFISHES, FARLOWELLA EIGENMANN AND EIGENMANN (PISCES, LORICARIIDAE)

Species of Farlowella Eigenmann & Eigenmann (Loricariidae) are catfish es that morphologically and behaviorally mimic sticks. The genus is wi dely distributed and common throughout much of South America, includin g the Amazon, Orinoco, and Paraguay drainages and Maracaibo Basin. Man y species are common bur poorly known, and the specimens cited in publ ications and housed in museums have rarely been identified to species. Twenty-five species of Farlowella are recognized as valid including s ix that are described as new. In Farlowella vittata and F. mariaelenae , the two species for which large samples exist, the only characters t o show allometric variation are snout-mouth length, snout-eye length, and number of jaw teeth. The only characters to show sexual dimorphism are snout-mouth, snout-eye, head, and anal fin lengths, and body widt h and depth. Unordered character states of 34 morphological characters were analyzed phylogenetically. Nineteen species of Farlowella were p laced in six Species groups that were recognized as monophyletic in bo th the strict and majority rule consensus trees. Six species have unce rtain relationships and were nor placed in a species group.