Meeting Abstract

3.1  Sunday, Jan. 4  Evolution of sexually dimorphic novelties and reproductive strategies in fishes of the family Characidae (Teleostei: Ostariophysi) JAVONILLO, R.*; MALABARBA, L.R.; WEITZMAN, S.H.; BURNS, J.R.; George Washington University; Universidade Federal do Rio Grande do Sul (Porto Alegre, Brazil); National Museum of Natural History, Smithsonian Institution; George Washington University rjavonil@gwu.edu

Approximately 1,000 freshwater fishes from South and Central America are assigned to the family Characidae. Both reproductive modes of external fertilization and insemination occur in this group. The latter is relatively uncommon among teleost fishes, yet appears widespread within a characid lineage called Clade A, and may be correlated with the evolution of certain anatomical traits. Quantitative studies of such correlations have been impeded by lack of a well-resolved phylogenetic hypothesis. We present a phylogeny that includes representatives of several subfamilies and incertae sedis genera, and is based on DNA sequence data from nuclear and mitochondrial genes. Reproductive modes and sexually dimorphic traits, such as fin-ray hooks and gill glands, are optimized onto the phylogeny, allowing assessment of the homology of and correlation among such traits across the family. These preliminary data reject the monophyly of several suprageneric taxa and imply that insemination has multiple origins in Characidae.