Epizootiology of the parasitic dinoflagellate Hematodinium sp. in the American blue crab Callinectes sapidus*

Diseases of Aquatic Organisms

Gretchen A. Messick¹  , Jeffrey D. Shields¹ 

关键词: Hematodinium sp.;    Callinectes sapidus;    Seasonality;    Size;    Salinity;    Disease;    Dinoflagellate;   

DOI  :  10.3354/dao043139

学科分类：生物科学（综合）

来源: Inter-Research

【 摘 要 】

ABSTRACT: Hematodinium sp. is a parasitic dinoflagellate that infects and kills blue crabs Callinectes sapidus. Periodic outbreaks of dinoflagellate infections with subsequent high host mortalities prompted a study of the epizootiology anddistribution of the crab pathogen. Hemolymph samples from over 13000 crabs were assessed for infections over 8 yr. Moderate to high prevalences were found at several locations along the Atlantic and Gulf coasts of the United States. In the coastal bays ofMaryland and Virginia, prevalence followed a seasonal pattern, with a sharp peak in late autumn. Infections were significantly more prevalent in crabs measuring less than 30 mm carapace width; host sex did not influence prevalence. Prevalences werehighest in crabs collected from salinities of 26 to 30�?; no infected crabs were found in salinities below 11�?. Intensity of infection did not vary among crab sizes, molt stages, or sexes. Naturally and experimentally infected crabs died over 35 and 55 din captivity, with a mean time to death of approximately 13 and 42 d, respectively. Several other crustaceans, including gammaridean amphipods, xanthid (mud) crabs, and the green crab Carcinus maenus, were found with Hematodinium-likeinfections. Considering its widespread distribution and high pathogenicity, we suggest that Hematodinium sp. represents a significant threat to blue crab populations in high salinity estuaries along the Atlantic and Gulf coasts of the USA.

【 授权许可】

Unknown