THE DEVELOPMENT OF INTEGUMENTAL PORE SIGNATURES IN THE GENUS PLEUROMAMMA (COPEPODA, CALANOIDA)

Most studies on the pore signature of calanoid copepods have been made on adult females; very little is known of the ontogenetic development of the pore signatures and their sexual differences. Males, females and copepodids of five species in the metridinid genus Pleuromamma are examined. Interspecific differences in the pore signatures occur as early as copepodid III. Differences in the signatures of the copepodids arise from two sources: (1) species-specific rates of development of the adult signature; (2) development of the species-specific components of the adult signature. The cephalosomal signature is complete in copepodid V, and the metasomal and urosomal signatures are complete in copepodid VI, the adult stage. Sexual differences in the pore signature are found in copepodid IV and are primarily evident in the urosome of the adult. The species-specific components of the urosomal signature are greater in the female than in the male.