Publication Abstract

Population structure and reproductive biology of Pygospio elegans on an intertidal sandflat, Firth of Forth, Scotland

S.G. Bolam

The population dynamics and reproductive biology of a population of the spionid polychaete Pygospio elegans was studied at Drum Sands, Firth of Forth, Scotland, between March 1997 and February 1998. The population showed a seasonal recruitment pattern with two acute periods of larval recruitment during the year, one in spring and one in winter. Planktotrophic larvae were the only larval type produced throughout the year on Drum Sands, these were released at the 3 to 5 setiger stage and settled at a size of 18 to 22 setigers. The sex ratio was female-biased throughout the study period. When there was a high female:male sex ratio, the proportion of females brooding embryos or larvae decreased suggesting that sexual reproduction is the primary method of propagation and is perhaps limited by the availability of males. Asexual reproduction was not found to occur in the P. elegans population on Drum Sands. These findings give supporting evidence that there is a large variability in the reproductive activity within the species P. elegans.

Reference:

S.G. Bolam (2004) Population structure and reproductive biology of Pygospio elegans on an intertidal sandflat, Firth of Forth, Scotland. Invertebrate Biology, 123(3): 260-268