ALLOZYMES CHARACTERIZE SIBLING SPECIES OF BIPOLAR PRIAPULIDA (PRIAPULUS, PRIAPULOPSIS)

Electrophoretic polymorphism of glucosephosphate isomerase (Gpi) and phosphoglucomutase (Pgm) polymorphisms were assayed in the bipolar-di sjunct species pairs Priapulus caudatus/P. tuberculatospinosus and Pri apulopsis bicaudatus/Priapulopsis australis (phylum Priapulida). Numbe rs of genotypes from Gpi alleles and 14 Pgm* alleles generally did no t show deviations from Hardy-Weinberg expectations in composite popula tions sampled over geographic distances up to 500 km linearly measured . This genetic pattern suggests efficient population cohesion in a phy lum where pelagic larvae have not been observed. Sibling species in ge nera Priapulus or Priapulopsis from northern and southern polar seas d id not share identical allozyme alleles.