Reproductive biology and population ecology of the marine fan worm Sabella pavonina (Savigny) (Polychaeta: Sabellidae)

The reproductive biology and population ecology of the sabellid polychaete, Sabella pavonina (Savigny) inhabiting an intertidal sand bank in Langstone Harbour, Portsmouth, was investigated between February 2007 and June 2009. ‘Blind’ thrown quadrats and sediment cores were used to characterise population distribution patterns at the site, and monthly coelomic fluid samples from 30 individuals were used to investigate the reproductive biology of the population, sex of the specimen, the presence of coelomocytes and the development of oocytes. Highest population densities (30.58 m−2 ± 8.05) were recorded on the low shore (0.4 m above chart datum) where the largest size particle fractions and lowest percentage organic content were found. Poisson distribution analysis showed the population was ‘clumped’ at the shore level, with a maximum number of 188 individuals in a 0.25 m2 quadrat, and within individual quadrats with up to 23 individuals in a 100 cm2 subsection. Sabella pavonina has an annual reproductive c...