In situ measurement of recruitment, mortality, growth, and fecundity of Capitella sp. (Annelida: Polychaeta)

The development of a marking method using a vital dye enabled us to study the in situ recruitment, mortality, growth, and reproduction of Capitella sp. at 2 mud flats (the Grappler Inlet and Bamfield Inlet) near the Bamfield Marine Station, British Columbia, Canada.It was found that (1) recruitment at the 2 sites did not correspond with the larval abundance in the plankton, (2) juvenile mortality was size-dependent, and (3) juvenile mortality was directly related to the number of predators present in the habitats.These results suggest that juvenile mortality by predation is a major factor affecting the recruitment and population dynamics of Capitella sp. at our study sites.Marked siblings reared in experimental trays that were placed in the natural habitats grew at a rate similar to that of laboratory-reared specimens; both reached sexual maturity in 3.5 mo.Fecundity, egg size, and egg energy content, measured in situ, varied greatly, corresponding to our previous laboratory findings on the same species.