Meeting Abstract

P2.113  Wednesday, Jan. 5  Changes in glucose metabolism in Tanner crabs Chionoecetes bairdi infected with Hematodinium sp: TAMONE, S.L.*; MORADO, J.F.; University of Alaska Southeast; US National Oceanic & Atmospheric Administration sltamone@uas.alaska.edu

Bitter crab syndrome (BCS) is a fatal disease that affects many commercially important crabs and is caused by the dinoflagellate parasite Hematodinium sp.. There is a high incidence of the BCS in Tanner crabs Chionoecetes bairdi from southeastern Alaska. In certain regions, 100% of recently molted primiparous females are infected. We have the opportunity to collect infected and uninfected crabs from the wild and analyze metabolic changes as they occur from early to late stages of the disease. Multiparous, and primiparous female C. bairdi were collected near Auke Bay, Alaska and maintained in flowing seawater at the University of Alaska Southeast Marine Laboratory. An uninfected group of juvenile crabs was collected in Icy Straight, AK. Hemolymph was sampled weekly for visual identification of Hematodinium for histology, and for analysis of glucose concentrations. Metabolic rates were measured on infected primiparous and uninfected multiparous and juvenile crabs and these preliminary results will be presented. Histological changes of the dinoflagellat occurred in all of the infected crabs as the disease progressed through the motile dinospore stage. Infected females hosted only one type of motile dinospore; macrodinospore or microdinospore, and all females succumbed to the disease either soon after sporulation or before. Metabolic changes were measured over the course of the disease and included circulating glucose which was significantly lower in infected crabs when compared to uninfected crabs (6.4 ± 2.3 mg/dl compared to 12.2 ± 4.2 mg/dl). Circulating glucose decreased to non-detectable levels at the later stages of the disease. Eyestalk ablation, a technique that removes the hyperglycemic hormone and normally decreases circulating glucose in crustaceans was not able to decrease this metabolite in infected crabs.