Reproduction in the Hermit Crab Pagurus Longicarpus (Decapoda: Anomura) From the Coast of New Jersey

Abstract

Trends in reproductive activity of an intertidal population of Pagurus longicarpus from coastal New Jersey were studied from 1985-1990. Brooding occurred 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 of breeding in March and April were <10?C. A rapid decline in ovigerous 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 generally 2.2-2.3 mm. The number of embryos in a brood was positively correlated with SL, but there was considerable variability in this relationship. The maximum number of embryos in a brood among 474 counted, was 1,426 (from a 3.70-mm crab). Embryos were attached to pleopods 2, 3, and 4, with most attaching to the third. Mature oocytes observed and counted in nonovigerous and postovigerous 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.