A telemetric study of microhabitat selection by premolt and molting blue crabs, Callinectes sapidus (Rathbun), within a subestuary of the Pamlico River, North Carolina

The purpose of this study was to identify the physicochemical characteristics of microhabitats selected by molting blue crabs and to obtain further information concerning the behavior of premolt crabs prior to ecdysis. Premolt blue crabs (both mature males and pubertal females) were tracked until ecdysis using ultrasonic telemetry. Premolt movement patterns and certain characteristics of the ecdysial habitats were measured. There was no detectable difference between males and females in movement patterns or habitat depth, pH, dissolved oxygen, turbidity, salinity, sediment type, or shoreline preference. However, female crabs were found in habitats containing higher bivalve densities than the habitats occupied by male crabs. In addition, habitats used during premolt by male and female crabs had higher bivalve densities than did ecdysial habitats. Premolt crabs became more selective of habitat salinity and oxygen as they approached ecdysis. A decrease in the variability of habitat salinity was observed thre...