Excessive carbohydrates (CHO) in diets for largemouth bass (LMB), Micropterus salmoides, are suspected of accumulating glycogen in hepatocytes, which may result in liver dysfunction. This study evaluated the effect of graded levels of dietary CHO on growth, survival, and liver histology of LMB. One hundred feed-trained advanced fingerling LMB (128.5 6 21.5 g) were stocked into each of nine 3400-L polyethylene tanks. Tanks were randomly assigned one of three experimental diets containing different CHO levels (13, 19, or 25% of diet). The extruded diets were approximately isonitrogenous (42% crude protein) and isocaloric (3 kcal/g energy). There were three replicate tanks per dietary treatment. Bass were fed to apparent satiation twice daily for 148 d. Survival was significantly higher (P # 0.05) for fish fed the 13 and 19% CHO diets (89 and 90%, respectively) compared to those fed the 25% CHO diets (82%). Average harvest weight of fish fed the 13% CHO diet (380 g) was significantly greater (P # 0.05) than for fish fed other diets. Average harvest weight of fish fed the 19% CHO diet (347 g) was significantly greater (P # 0.05) than for fish fed the 25% CHO diet (310 g). Specific growth rates (%/d) were significantly higher (P # 0.05) in fish fed the 13 and 19% CHO diets than in fish fed 25% CHO diet. Feed conversion ratios for fish fed the 13 and 19% CHO diets (2.3 and 2.4, respectively) were both significantly lower (P # 0.05) than in fish fed the 25% CHO diet (3.6). There were no significant differences (P . 0.05) in condition factor, protein efficiency ratio, hepatosomatic index, or liver glycogen concentration among fish fed the different experimental diets. Overall, mean blood glucose levels in fish fed the 13 and 19% CHO diets (61.0 and 71.2 mg/dL, respectively) were significantly lower (P # 0.05) than in fish fed the 25% CHO diet (87 mg/dL). Histopathological examination of livers from fish fed the three diets was used to score the degree of vacuolization of hepatic tissues (0 5 normal, 1 5 slight, 2 5 mild, 3 5 moderate, and 4 5 severe). Regression of vacuolization scores on dietary CHO levels was statistically significant (P # 0.05) and indicated a direct positive relationship between liver vacuolization and dietary CHO level (R 2 5 0.57). These data indicate that LMB grow faster and use feeds more efficiently when CHO are maintained at ,20% of diet. CHO levels .20% negatively impacted liver histology, but a liver tissue analyses did not document glycogen accumulation.

ABSTRACT. Pure cultures of fungus were isolated from commercially raised channel catfish Ictalurus punctatus exhibiting overt signs of a winter syndrome locally termed 'winter kill' The fungal isolates were identified as members of the genus Saprolegnia. Histopathological examination of fungal associated skin lesions from diseased fish exhibited a complete lack of bacteria or of leukocytic infiltration around the site(s) of hyphal penetration. In order to determine if the fungus was the origin of disease or an opportunistic secondary pathogen, controlled laboratory studies were conducted which conclusively proved that if channel catfish were immunosuppressed by a rapid decrease in environmental water temperature from 22 to 1OeC, the Saprolegnia sp. isolates rapidly infected catfish to cause 92 O/O infection (skin lesions) and 67 % mortality within 21 d post-challenge. Examination of laboratory-infected fish revealed fungal associated skin lesions with histopathology identical to that obtained from fish in the field, i.e. there was a complete lack of bacterial or leukocytic infiltration around the lesion site. These results strongly suggest that 'winter lull' syndrome in catfish is an immunodeficiency disease of fungal rather than bacterial etiology and is probably better termed 'winter saprolegniosis'

No abstract

No abstract

The purpose of this literature review, the second in a series following one on traumatic injuries and fatigue, is to identify potential health hazards to inform a study of occupational health and safety among fish harvesters in the Gulf of Mexico (GoM). Fish harvesters are potentially at a high risk of occupational illnesses in GoM fisheries. GoM fishers engage in harvesting shrimp, finfish, oysters, crabs, and clams. Method: The method is a narrative literature review. Search terms that included safety, seafood, occupational, fishing, oyster, clam, shrimp, crab, and GoM were used to identify relevant literature in combination (i.e., a string search). Results: A total of 53 manuscripts were reviewed, of which only two regarded the GoM, but 19 were from the US Atlantic Coast. Musculoskeletal disorders are widespread across the fishing sector. Other hazards include bites and stings from aquatic animals (some of which may be life-threatening), vessel engine noise, dermatoses, and other skin afflictions (including possible strep infection of wounds), solar ray-induced eye diseases, and respiratory exposures (such as to protein aerosols) that can cause asthma. Diving poses multiple breathing and other hazards. Conclusion: While fish harvesters are protected from respiratory problems when working on the well-ventilated deck and dermal hazards by wearing gloves, musculoskeletal, bite and sting, ocular, engine-related hearing loss, and skin, lip, and eye cancer hazards are potentially serious risks among GoM fish harvesters.