Abstract:
Leptosynapta clarki is a brooding apodid sea cucumber found on the intertidal mudflats on the west coast of Vancouver Island, Canada. In the early spring (April/May), juveniles burrow into the sediment after release from the mother by rupturing of the body wall. There is potential for dispersal after release, but the juveniles form a distinct recruitment pulse in the adult habitat. Monitoring of the population in the field shows rapid growth from a mean size of 1 to 2 mm at release to a maximum of 16 mm in August. After August, the juveniles become pigmented and are indistinguishable from the adult population. Growth estimates from the laboratory show that during the reproductive season following their birth (November to December), the sea cucumbers are a maximum of 35.5 mm in length (mean 18.7 mm), and are reproductively active as males. At the age of 1 yr the mean size is 21.1 mm with a maximum length of 44 mm. This study provides the first data on recruitment in an apodid sea cucumber and provides detailed information on the growth rates and early life history of L. clarki.