| Abstrakt: |
We used biomarkers to assess the health of two populations of brown bullheads Ameiurus nebulosus, one from an urban, industrialized section of the Schuylkill River (SR), Philadelphia, Pennsylvania, and the other from Hopkins Pond (HP), in suburban New Jersey, which was not affected by industry. We evaluated health using histopathology, condition factor ( K), hepatosomal index (HSI), prevalence of parasites, health assessment index (HAI), and population age structure. Sediment analysis revealed that both sites contained similar levels of polynuclear aromatic hydrocarbons (PAHs). Brown bullheads from the SR were longer and heavier than brown bullheads from HP and exhibited more external lesions. There were no hepatic lesions in brown bullheads from either site. Condition factor was higher in SR fish, but due to length differences between the two populations, was not a reliable indicator of general health. Hepatosomal index was similar between both populations, although the presence of numerous cestodes in the visceral organs, including the liver, of HP brown bullheads confounded the interpretation of the HSI. The incidence of parasitism was significantly greater in HP fish than in SR fish. The HAI was significantly greater in SR brown bullheads, indicating more organ abnormalities in SR fish than in HP fish, including more abnormalities of the fins, barbels, and mouth. Population age structure was older for HP brown bullheads than for SR fish, indicating a shorter lifetime for SR brown bullheads. Although PAH levels were similar between the two sites, SR brown bullheads were less healthy than HP brown bullheads, as indicated by several biomarkers. Histopathology, health assessment index, and population age structure were the most informative biomarkers. [ABSTRACT FROM AUTHOR] |
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