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 st udy the in situ recruitment, mortality, growth, and reproduction of Ca pitella sp. at 2 mud flats (the Grappler inlet and Bamfield Inlet) nea r 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 pred ators present in the habitats. These results suggest that juvenile mor tality by predation is a major factor affecting the recruitment and po pulation 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 r eached sexual maturity in 3.5 mo. Fecundity, egg size, and egg energy content, measured in situ, varied greatly, corresponding to our previo us laboratory findings on the same species.