Speciation in erect morphotypes of Alcyonidium verrilli (Bryozoa, Ctenostomata) from the Chesapeake Bay

Examination of Alcyonidium verrilli from the lower Chesapeake Bay revealed two morphotypes. Statistical morphological comparisons, electrophoresis of two enzymes, chromosomal number determination, and ecological association observations were performed to determine if the two morphotypes were separate species. Morphological comparisons using Kruskel-Wallis were found to be statistically different. Electrophoretic results showed no difference in enzyme mobility. Morphotype 1 chromosome work yielded 2n is approximately 44 based on bivalents. Morphotype 2 chromosome work yielded a 2n = 28, and a karyotype was constructed. Both morphotypes are preyed on by Doridella obscura. Arcohaetium alcyonidii cylindrium was observed infesting Morphotype 1. The simplest explanation is the two morphotypes of Alcyonidium verrilli are separate species.