Rhizocephalan Parasites of Mud Crabs in South Carolina Estuaries

Rhizocephalan parasites often infect commercially important crustacean species such as the blue crab (Callinectes sapidus). In this experiment, the prevalence of rhizocephalan parasites was determined by sampling mud crabs (Panopeus herbstii) in three different locations; Huntington Beach State Park, Waites Island, and Murrells Inlet. Crabs were determined to be parasitized by the presence of an externae extruding from their apron. Unparasitized crabs were also collected to serve as a control group. The externa were removed and DNA extractions were performed. Polymerase chain reactions (PCR) were done to prove whether the crabs were parasitized by Loxothylacus texanus or Loxothylacus panopaei. Results show that all the crabs with externae were infected by a form of Loxothylacus. The unparasitized crabs that were sampled for control also tested positive for Loxothylacus infection. The restriction digests\u27 results showed that some of the crabs were infected by L. texanus, which is supposed to be specific only to the blue crab (Callinectes sapidus). Its range is also supposed to be limited to Florida and the Gulf of Mexico, but these crabs were sampled well above that range