Isoenzymes and Taxonomy in Scandinavian Hydroids (Cnidaria, Campanulariidae)

Abstract

Acid phosphatases, esterases and leucine aminopeptidases were studied in Campanularia integra, Clytia hemisphaerica (the johnstoni form), Laomedea ftexuosa, Gonothyraea loveni, Obelia geniculata, O. longissima andO. dichotoma, using polyacrylamide gel electrophoresis. Species-specific patterns were obtained, notably regarding acid phosphatase, despite strong individual variation. The electrophoretic results combined with differences in morphology and cnidom indicate that O. longissima and O. dichotoma are separate species. The acid phosphatase patterns of the two species and of O. geniculata showed basic similarities, supporting their assignment to a common genus. The profound differences in the acid phosphatase patterns of C. integra and L. flexuosa, may in conjunction with morphological distinction justify their assignment to separate genera. C. integra also included specimens of caliculata morphology: however, these did not deviate in their band patterns. Electrophoretograms of the typical O. dichotoma resembled those of the dubia and plicata forms. Moreover, O. gelatinosa with free Obelia medusae (sensu Hincks 1868) is suggested to be conspecific with O. longissima. The present study indicates that electrophoretic analyses, particularly of acid phosphatases presenting highly reproducible patterns, is a valuable complement to morphological characters when studying the taxonomy in hydroids.