Application of the Pearl model to analyze fecal coliform data from conditionally approved shellfish harvest areas in seven Texas bays.

The U.S. National Shellfish Sanitation Program (NSSP) 14/43 standard states that conditionally approved shellfish growing areas must be closed for harvest when the geometric mean of fecal coliform concentration exceeds the NSSP limit of 14 most probable number (MPN)/100 mL, or the estimated 90th percentile of fecal coliform concentrations exceeds 43 MPN/100 mL for a five-tube test. The authors hypothesized that the NSSP 14/43 standard is not sufficient to protect the public from risks from consumption of biologically contaminated shellfish and the standard should be modified to 8/26 MPN/100 mL. To verify this hypothesis, the authors analyzed fecal coliform data from conditionally approved shellfish harvest areas of seven Texas bays using the Pearl sanitation model. Results showed that the shellfish closure rules mandated by the Texas Department of State Health Services actually enforced the "Pearl" limits of 8/26 MPN/100 mL, and not the NSSP limit of 14/43 MPN/100 mL.

Growth of juvenile white sturgeon (Acipenser transmontanus) fed different purified diets.

Two experiments were conducted to develop a purified diet suitable for studying nutritional requirements of juvenile white sturgeon (Acipenser transmontanus). In the first experiment, growth and survival rates of fish fed a purified diet (SPD) containing 50% casein:wheat gluten:egg white (6.2:3.0:0.8) and 8% refined soy lecithin were significantly (P less than 0.05) better than those fed a commercial nonpurified rainbow trout diet, a purified rainbow trout diet containing 50% casein:gelatin (7:3) or a purified catfish diet containing 34% spray-dried egg white. In the second experiment, fish fed SPD diet with or without cholesterol but with the same amount of lipid grew equally well. Fish fed SPD diet with lecithin grew significantly better than those fed SPD diet with its 8% lecithin replaced with an equal amount of an oil mixture. In both experiments, fish with good growth and survival rates also had significantly lower body moisture and higher protein and lipid contents than fish with poor growth and survival rates. Results suggest that the SPD diet with lecithin and without cholesterol (SPD-C) is a suitable purified diet for juvenile white sturgeon.

Microbial Flora of Pond-Reared Shrimp ( Penaeus stylirostris , Penaeus vannamei , and Penaeus setiferus ).

Aerobic plate counts of fresh pond-reared shrimp ( Penaeus stylirostris , Penaeus vannamei , and Penaeus setiferus ) ranged from 1.5 × 103 to 1.3 × 104 per gram. Coryneform bacteria and Vibrio spp. dominated the microbial flora of shrimp. Aerobic plate counts of pond waters ranged from 6.1 × 102 to 2.2 × 104 per milliliter. Vibrio spp. usually were dominant in pond waters. Enterococci and coliform levels in shrimp were low. Fecal coliforms were present in only one of 11 shrimp samples. No Escherichia coli was recovered from pond-reared shrimp. Salmonella , Vibrio parahaemolyticus , Bacillus cereus , and Clostridium perfringens were not recovered from either shrimp or pond waters. No relationship could be established between changes in numbers and types of microorganisms in pond-reared shrimp or pond waters and changes in characteristics of the pond waters such as temperature, salinity, dissolved oxygen, and pH.