A MULTI-PARASITE APPROACH TO UNDERSTANDING BLACK GILL AND WHITE SHRIMP <i>Penaeus setiferus</i> (Linnaeus, 1767) HEALTH
Zuidema, Sarah Rose
White shrimp <i>Penaeus setiferus</i> support one of the highest value commercial fisheries in South Carolina and play important ecological roles in estuarine ecosystems, as both consumers and prey, which makes their health an important area of research. Body condition was used in this study to investigate variability in <i>P. setiferus</i> health. The objectives of this project were: 1) to determine variability in <i>P. setiferus</i> parasite communities and black gill across spatial, temporal, and ontogenetic scales; 2) to understand the relationship between black gill and <i>P. setiferus</i> parasites; and 3) to examine the potential impacts of <i>P. setiferus</i> parasites and black gill on shrimp body condition. Shrimp were collected from May through November in tidal creek and open harbor regions of the Charleston Harbor watershed and were examined for black gill and parasites. Parasite communities were composed of nine taxa: plagiorchiids, trypanorhynchs, lecanocephalideans, cyclophyllids, rhabditids, gregarines, microsporidians, as well as sessilid and apostome ciliates. This community was significantly different among shrimp habitats and among shrimp life stages. Both black gill and parasites were related to shrimp body condition. Black gill is the result of an immune response in shrimp and other crustaceans to eliminate pathogens. In South Carolina black gill is often associated with apostome ciliates, in addition to physiological impacts like decreased physical endurance. Plagiorchiids and trypanorhynchs were associated with lower shrimp body condition, whereas lecanocephalideans, gregarines, sessilid ciliates, and apostome ciliates were associated with higher shrimp body condition. In contrast to the negative physiological consequences previously related to black gill, shrimp with black gill had significantly greater body condition. Results from this study highlight the complexity of factors contributing to shrimp health and the need for further investigation of their impacts on shrimp populations.