Submitted to: Transactions of the American Fisheries Society
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 5/13/2008
Publication Date: 12/4/2008
Citation: Evans, J.J., Klesius, P.H., Shelby, R.A., Xu, D. 2008. Relationship between frequency of skin ulceration and total plasma immunoglobulin levels in atlantic menhaden from Delaware and Maryland inland bays. Transactions of the American Fisheries Society. 137 (6):1667-1673 Interpretive Summary: A high prevalence of ulcerative skin lesions in Atlantic menhaden from the inland bays of Delaware and Maryland has caused considerable public and governmental concerns. The appearance of fish with ulcerative lesions caused public questions on the safety of consuming seafood. Drs. Evans, Shelby, Xu and Klesius investigated a possible linkage between immune status of menhaden and the frequency of skin ulcers. The results of this 2-year investigation suggested a linkage between the immune status of fish and frequency of ulcers. Suppression of antibody-mediated immunity was correlated with the frequency of ulcers. The suppression of antibody-mediated immunity resulted in an increased disease susceptibility. The investigation suggested that ulceration of menhaden may not be solely associated with Pfisteria-like microbes as had been previously described, but may be associated with other infectious agents and physiological and environmental factors of Delaware and Maryland inland bays.
Technical Abstract: In the summer and fall of 2000, a high prevalence of ulcerative skin lesions in Atlantic menhaden, Brevoortia tyrannus, from inland bays of Delaware and Maryland caused public and governmental concern. We investigated the possible linkage between total plasma immunoglobulin (Ig) levels and the frequency of skin ulceration in Atlantic menhaden from inland bays of Delaware and Maryland in 2000 and 2001. Total plasma Ig levels were determined using goat anti-menhaden Ig in an ELISA. Total plasma Ig levels in non-ulcerated (n = 543) and skin-ulcerated menhaden (n = 120) were 7.4 mg/ml and 4.2 mg/ml, respectively, in three stratified sizes (large, medium, and small) of fish and both years. This highly significant (P < 0.01) decrease in total plasma Ig levels between non-ulcerated and skin-ulcerated fish was not found to be significantly (P < 0.01) influenced by the size of the menhaden. The frequency of skin ulcers from the large (27%) and medium (21%) size fish was significantly (P < 0.01) greater compared to the frequency of skin ulcers in small (6%) size fish. The data indicated that non-ulcerated larger size fish had significantly higher (P < 0.01) total plasma Ig levels (8.5 mg/ml) compared to the total plasma Ig level (6.1 mg/ml) of the non-ulcerated smaller fish. In 2000, the total plasma Ig levels from both larger (126 mm) and smaller (73 mm) size skin-ulcerated menhaden (2.4 and 2.3 mg/ml) were significantly (P = 0.022) decreased from Ig levels corresponding to the same size non-ulcerated menhaden (4.0 and 4.4 mg/ml), respectively. In 2001, total plasma Ig levels in both non-ulcerated and skin-ulcerated menhaden of all sizes were not significantly (P > 0.05) different, but they were highly significantly (P < 0.01) increased compared to total plasma Ig levels from corresponding menhaden in 2000. Moreover, we found that the frequency of skin ulceration was highly significantly (P < 0.01) decreased in all size menhaden in 2001 compared to corresponding menhaden in 2000. Data strongly suggests a possible linkage between total plasma Ig levels and the frequency of skin ulceration.