Meeting Abstract
Marenzelleria viridis is a spionid polychaete native to the east coast of North America that has been introduced into northern European waters. The objective of this study was to examine the regeneration capacity and parasitism of M. viridis from Long Island, New York. In the field, 7% of the worms exhibited regeneration. In the laboratory, worms were ablated at the 10th-50th chaetiger and their regeneration documented. Anterior morphogenesis was similar to previous studies on spionids, with wound healing, blastema formation, and differentiation of segments occurring within 14 days. The number of segments replaced was equal to the number removed for up to 10 segments but up to 17 segments were replaced when higher numbers were ablated. The impact of salinity on regeneration was tested in worms cultured at five salinity treatments (0-24ppt). All specimens cultured at 5-24ppt successfully completed regeneration whereas 75% of specimens cultured at 0ppt died. Salinity did not effect regeneration time but did effect the percentage of chaetigers regenerated (highest at 15ppt). During examination of M. viridis from the field, putative trematode cysts were discovered in their body cavity. DNA barcoding confirmed the presence of three species of trematodes. Brown bodies were also recovered from worms and molecular testing confirmed the presence of trematodes, indicating an immune response leading to encapsulation. This is the first confirmation that trematodes use M. viridis as a second intermediate host. Future research should explore regeneration and the role of M. viridis in trematode life cycles, particularly in its non-native range.
