Paradoxical polyembryony? Embryonic cloning in an ancient order of marine bryozoans

• DOI: 10.1098/rsbl.2004.0259
• Publication Date: 2005-05-16T19:28:34Z
• Authors: Roger N Hughes; M. Eugenia D'Amato; John D.D Bishop; Gary R Carvalho; Sean F Craig; Lars J Hansson; Margaret A Harley; Andrew J Pemberton
• Keywords: Polyembryony; Asexual reproduction; Sexual reproduction

Prolific polyembryony is reported in few major taxa, but its occurrence has generated theoretical debate on potential conflict between sexual and asexual reproduction. It is, therefore, important to genetically confirm a widely cited inference, based microscopy, that characterizes marine bryozoans of the order Cyclostomata. Microsatellite genotyping brooded embryos maternal colonies conclusively demonstrated polyembryony, while genetic variation among broods within indicated outcrossing via water-borne sperm, rocky-shore species Crisia denticulata . The characteristically voluminous brood chamber cyclostomes judged be an adaptation linked larval cloning hence indicator polyembryony. We speculate although almost universal crown-group Cyclostomata probably attributable phylogenetic constraint, adaptive consequences are likely significant.