GENETIC AND MORPHOLOGICAL EVIDENCE THAT THE EASTERN PACIFIC DAMSELFISH ABUDEFDUF DECLIVIFRONS IS DISTINCT FROM A-CONCOLOR (POMACENTRIDAE)

No consensus exists in the systematic literature about whether the Mex ican night-sergeant, Abudefduf declivifrons, from Baja California and the Sea of Cortez, is distinct from the Panamic night-sergeant, Abudef duf concolor, from the rest of the tropical eastern Pacific. We presen t evidence from electrophoretic comparisons of proteins, nucleotide se quence comparisons of the cytochrome oxidase I gene of mitochondrial D NA, and quantitative comparisons of morphology. All agree that the two nominal species are distinct. Based on analysis of isozyme and mitoch ondrial DNA data from the Caribbean species of night-sergeant, Abudefd uf taurus, we suggest that A. declivifrons split from the lineage lead ing to A. concolor and A. taurus before the Pliocene rise of the Isthm us of Panama. The two night-sergeants from the eastern Pacific differ significantly in body, snout, and caudal peduncle depth and can be dis tinguished by the condition of the suborbital margin (adnate in A. con color, semi-adnate or exposed in A. declivifrons).