UTILIZATION OF SHALLOW ESTUARINE HABITATS IN SOUTH CAROLINA, U.S.A., BY POSTLARVAL AND JUVENILE STAGES OF PENAEUS SPP. (DECAPODA: PENAEIDAE)

Abstract

ABSTRACT Penaeus spp. were sampled in 3 tidal marsh creeks in poly-, meso-, and oligohaline salinity regimes from February 1986 to June 1988. Occurrence of postlarvae of Penaeus in plankton collections from the marsh creeks was seasonal, with peaks occurring in February and March for the brown shrimp P. aztecus, July for the white shrimp P. setiferus, and August for the pink shrimp P. duorarum. White and pink shrimp postlarvae were most abundant at the polyhaline site, while density of brown shrimp postlarvae was greatest in the mesohaline creek. Postlarvae of all three species were more numerous at night, with white and brown shrimps occurring in greater densities at the surface. Juvenile brown and white shrimps were most abundant at the meso- and oligohaline creeks, while few juvenile pink shrimps were collected at any site, despite being numerically dominant (42% of the total) as postlarvae. Utilization of the marsh surface and drainage rivulets in each creek was determined by sampling with a suction pump and cylindrical drop sampler, flume nets, and a stationary bottom net. Penaeus setiferus was the most abundant species collected from the marsh surface, with greatest densities at the mesohaline creek. Although the marsh surface and drainage rivulets appear to be important nursery habitats for penaeid shrimps in South Carolina, densities were much lower than those reported in marshes along the Gulf of Mexico. The densities of penaeid shrimps in nursery habitats of South Carolina are likely influenced by higher tidal amplitude and less reticulation of marshes, compared to those in the Gulf of Mexico.