Sibling species in the marine pollution indicator Capitella (polychaeta).

Electrophoretic patterns for eight enzyme loci clearly distinguish six sibling species in the well-known pollution indicator worm, Capitella capitata. Unlike sibling species of Drosophila, the Capitella species have virtually no alleles in common. Close examination has revealed only slight morphological differences between species, while life histories and reproductive modes are very distinct. The Capitella species are ideally suited for genetic and evolutionary studies.