Population Dynamics of the Mysid Shrimp Mysidopsis Bigelowi W. M. Tattersall in a Temperate Estuary

Abstract

ABSTRACT Mysidopsis bigelowi, a common epibenthic mysid crustacean, was collected in a New Jersey estuary to determine its seasonal abundance, distribution, and life history pattern. Mysids were sampled with an epibenthic sled, and densities of M. bigelowi were among the highest reported for any shallow-water mysid. This mysid occurred in all subtidal areas of the high salinity embayment throughout the year, but was most abundant in sandy habitats near the inlet and in the ocean. Variations in abundance between stations and between cruises, which were often greater than two orders of magnitude, were attributed to patchy distribution and a high degree of motility. A significant correlation was observed between the abundance of M. bigelowi and that of the dominant sympatric mysid Neomysis americana. An inshore migration of adult M. bigelowi in spring coincided with the onset of reproduction of the overwintering generation. Females from 4.4-8.5 mm total length incubated from 5-43 young; the mean was 17.4. The number of eggs or larvae was linearly related to female length. Individuals produced multiple broods and reproduction was continuous from April through November. Abundance, distribution, and life history adaptations of M. bigelowi in Hereford Inlet are compared to those of populations from New England to Texas.