Divergence between Populations of a Monogamous Polychaete with Male Parental Care: Premating Isolation and Chromosome Variation

摘要

Low dispersal and sexual selection are characteristic of the coastal polychaete Nereis acuminata Ehlers 1868 (also known as Nereis arenaceodentata Moore 1903 and Nereis (Neanthes) caudata Delle Chiaje 1841). A study assessed levels of premating isolation between populations of the polychaete. Four North American populations were used, two from the Atlantic and two from the Pacific. Worms from all sites (1) were collected in 1987 and 1988 from the same habitat type, (2) were morphologically similar and keyed out as N. acuminata, and (3) reproduced monogamously and exhibited male parental care, an extremely rare reproductive mode in marine invertebrates. Results suggest strongly that the Atlantic and Pacific populations have been allopatric for a long time, and are different species.