P3.185 Friday, Jan. 6 Morphology, ecology, and reproduction of the cryptogenic sponge associate Polydora colonia (Polychaeta: Spionidae) WILLIAMS, Jason*; DAVID, Andrew; Hofstra University; Hofstra University email@example.com
The spionid polychaete Polydora colonia (Moore 1907) is a widely distributed polydorid worm, typically found associated with sponges. The species was first described from Massachusetts and has been reported in other regions of the western Atlantic, the Mediterranean Sea and South Africa. In spite of many reports of the species, the natural history of P. colonia is virtually unknown and studies are needed to determine its status as an introduced species. The current work focused on collections of P. colonia from Long Island, New York made between 2007-2010. Polydora colonia was associated with two host sponges (Microciona prolifera and Halichondria bowerbankii) attached to docks; the worms reached densities as high as 7.8 worms/mm3 during July to August. Morphological research based on light and scanning electron microscopy showed the specimens agree with prior studies and no features were found that distinguish it from previous descriptions and museum specimens from around the world. Polydora colonia exhibited adelphophagy (nurse eggs consumed by developing larva) and the earliest free-swimming stage was a 7 chaetiger larva. Asexual reproduction (via architomy) was recorded for the first time in this species; overall prevalence of architomy was 24% (n= 780). Anterior regeneration was completed in 8 days and followed a similar morphogenic pattern to other spionids. Sponge material (including spicules) was found in the gut of 53% of worms examined (n=100), the first evidence of sponge feeding in polydorids. Polydora colonia appears to have been introduced to marinas in many localities around the world and further studies should be completed to examine its impacts, including effects of feeding on host sponges.