MORPHOLOGICAL TRENDS IN REDUCTION AND LOSS OF PAIRED FINS IN FISHES
Abstract
Fins and their supporting skeletons in fishes are homologous to the paired forelimbs and hindlimbs of terrestrial vertebrates. Like limbs, fin reduction or loss is not uncommon across fishes, resulting from multiple independent evolutionary events. Diverse degrees of reduction, up to complete loss, can be seen across families of fishes. The goal of this project is to precisely document the degree of fin loss at a family level across fishes, the most diverse clade of living vertebrates with close to 30,000 known species. I am focusing on Synbranchiformes, the swamp eels. In addition to data derived from the literature, I am generating new information by obtaining specimens from natural history collections and preparing bone and cartilage stained whole mounts. I mapped these data onto existing phylogenies to visualize and enumerate trends of fin loss and reduction. I will use phenotypic features in fins to develop hypotheses for the genetic basis of fin reduction in this clade using data from genetic mutants of zebrafish, a model organism.