Reproduction in the hermit crab Pagurus longicarpus (Decapoda : Anomura) from the coast of New Jersey

Trends in reproductive activity of an intertidal population of Pagurus long icarpus from coastal New Jersey were studied from 1985-1990. Brooding occur red from late March-October, with a sharp peak in ovigerous crabs in April (70.6-96.4% of yearly total). Mean water temperatures at the commencement o f breeding in March and April were <10 degrees C. A rapid decline in oviger ous crabs occurred in May and June and throughout the summer; ovigers were rare in September and October (4 among 849 crabs). The smallest oviger was 1.85 mm in carapace shield length (SL), although minimum length was general ly 2.2-2.3 mm. The number of embryos in a brood was positively correlated w ith SL, but there was considerable variability in this relationship. The ma ximum number of embryos in a brood among 474 counted, was 1,426 (from a 3.7 0-mm crab). Embryos were attached to pleopods 2, 3, and 4, with most attach ing to the third. Mature oocytes observed and counted in nonovigerous and p ostovigerous crabs suggest that some crabs may produce more than 1 brood in a season. Recruitment of benthic juveniles to the population began in May and continued throughout the summer and fall.