Two feeding trials were conducted with juvenile largemouth bass Micropterus salmoides to evaluate alternative plant and animal source proteins for their ability to replace fish meal in practical diets. The first trial was designed to identify the most promising candidates. The second trial was conducted to evaluate how much of the fish meal could be replaced by those candidates. In Study 1, feed‐trained largemouth bass (3.1 ± 0.7 g) were randomly stocked into 18114‐L glass aquaria at 25 fish per aquarium. Fish were fed one of six experimental diets, each containing approximately 38% crude protein and 10% crude lipid, to apparent satiation twice daily. The control diet (CTL) contained 30% fish meal and 34.5% soybean meal. Diets 2–6 each contained 15% fish meal and at least 34.5% soybean meal with the remainder of the protein made up of either meat and bone meal (MBM), soybean meal (SBM), poultry by‐product meal (PBM), a 50150 mixture of blood meal and corn gluten meal (BM/CG), or 50150 mixture of hydrolyzed feather meal and soybean meal (FMISBM). There were three replicate aquaria per dietary treatment. After 12 wk, there was no significant difference (P > 0.05) among treatments in survival which averaged 92% overall. Only fish fed the PBM or BM/CG diets had average individual weights and feed conversion efficiencies that were not significantly different (P > 0.05) from the control diet (CTL). In Study 2, the formulation of the control diet (CTL) remained the same. Based on their performance in the first trial, PBM and BM/CG were chosen to now replace 75 or 100% of the fish meal. Fish were stocked at an average weight of 6.9 ± 1.7 g. After 11 wk, fish fed diets containing the BM/CG mixture at both levels were significantly smaller (P 5 0.05) than fish fed other diets and at 100% replacement survival was reduced. Fish fed diets containing poultry meal as the primary protein source performed as well as those fed the control diet (CTL). It appears that PBM can completely replace fish meal in diets for juvenile largemouth bass without adverse effects on growth, feed efficiency, or body composition.

The freshwater prawn Macrobrachiurn rosenbergii is a commercially important culture species in the South Central United States. Two major constraints in the commercial culture of the freshwater prawn in the U.S. are poor survival during live transportation of seed-stock to growout ponds, and live transportation of pond harvested prawn to distant live markets due to the territorial and cannibalistic nature of prawn. The use of anesthetics could possibly improve transport survival; however, to date anesthetic agents have not been evaluated for use with prawn. Two trials were conducted with juvenile freshwater prawn to compare the efficacy of anesthetics commonly used on fish. The first trial was designed to identify the most promising candidates. In Study 1, tricaine methanesulfonate (MS-222), 2-phenoxyethanol, quinaldine sulfate (quinaldine), clove oil, and Aqui-STM were evaluated at 25 and 100 mg/L for 1 h in three replicate 10-L glass containers, containing five juvenile prawn each. Relative sedation level was determined every 3 min for 1 h, then recovery time and survival were measured. In Study 1, MS-222 and 2-phenoxyethanol were determined to be ineffective on prawn at all rates tested. Based on their performance in Study 1, quinaldine, clove oil, and AquiSTM were evaluated at 100, 200, and 300 m f i in Study 2. Observations were determined as in Study 1. Clove oil and AquiS" induced anesthesia faster and at lower concentrations than quinaldine. At the highest treatment rate (300 m e ) prawn suffered 60% mortality in the Aqui-S" treatment, 13% mortality in the quinaldine treatment, and 0% mortality in the clove oil treatment and control following a 1-h exposure to these concentrations. Based on these data, AquiS" and clove oil applied at 100 mg/L may be suitable anesthetic treatments for prawn. Additional research is needed to determine optimal time and dose relationships to minimize stress during holding, handling, and transportation of prawn. Zar, J. H. 1984. Biostatistical analysis, 2nd edition.

The effects of water temperature on growth rate, survival, and biochemical composition c juvenile largemouth bass Micropterus salmoides were evaluated under controlled conditions in tanks for 12 wk. Feed-trained juvenile largemouth (9.1 2 1.9 g) were stocked into nine 3,610-L polyethylene tanks inside a greenhouse structure a t 140 fish/m3 (500 fish/tank). Three treatment temperatures were evaluated (20,26, and 32 C) with three replicates per treatment. Bass were fed to apparent satiation twice daily using a commercially available floating salmonid diet (45% crude protein and 16% lipid). After 97 d bass grown a t 26 and 32 C had significantly higher (P < 0.05) average weights, SGR, condition factor (K), and production rates (kg/m3) than those in the 20 C treatment. Bass in the 26 C treatment had significantly lower (P < 0.05) FCR and higher percent protein deposit (PPD) than bass raised at 20 and 32 C, which were not significantly different (P > 0.05). There were no significant differences (P > 0.05) in survival among treatments which averaged 97%, overall. Bass raised at 32 C had higher (P < 0.05) lipid levels in the liver than other treatments. Whole body amino acid concentrations were not significantly impacted (P > 0.05) by culture temperature. Largemouth bass raised at 26 C had significantly lower (P < 0.05) levels of stearic acid (18:O) and significantly higher (P < 0.05) levels of arachidonic acid (20:4 n-6) than bass raised at 20 or 32 C. Bass raised at 32 C had significantly higher (P < 0.05) levels of Linoleic acid (18:2 n-6), total saturates, and dienes than bass raised at 26 or 20 C. These data indicate that growth and feed conversion efficiency are reduced at 20 C. Growth is similar at 26 and 32 C, but feed and dietary protein are more efficiently utilized at 26 C.

Seedstock-costs of the freshwater prawn Macrobrachium rosenbergii can represent 450% of the total production costs. The purpose of this study was to evaluate the e¡ect of culture tank colouration on survival, metamorphosis rate, weight and time required to reach the postlarval (PL) stage. Newly hatched prawn larvae were stocked into eighteen 16-L plastic culture tanks at a density of 30 L À1 . Tank colours evaluated were red, black, white, blue, green and yellow. Larval prawns were fed brine shrimp (Artemia franciscana) nauplii and a supplemental diet. Data indicated that larval tank colour had no signi¢cant impact (P40.05) on the ¢nal PL size or days required to reach PL stage. However, total survival was signi¢cantly higher (Po0.05) in red and green tanks (84% and 78% respectively) than in white and blue tanks (56% and 44% respectively). Survival in the yellow and black tanks (71% in both) was not signi¢cantly di¡erent (P40.05) from the red, green or white treatments, but was signi¢cantly higher (Po0.05) than the blue treatment. This could have a signi¢cant ¢nancial impact on commercial hatchery, and growout production, as most larval tanks currently in use are blue or black.

Research and development e¡orts concerning freshwater prawn farming have in the past been principally conducted in tropical regions. However, activities in temperate regions also date back several decades. Culture of Macrobrachium in temperate zones o¡ers positive opportunities, despite the inability to culture year-round. Unique problems imposed by a restricted growing season must be addressed, and opportunities capitalized on, to attain commercially viable production in these regions. Much recent research in the South and Central USA has been directed towards intensifying production (kg ha À1 ) without decreasing average harvest sizes or deteriorating water quality. Particular areas of research include evaluating and maximizing the relative contributions of natural foods, e¡ects of arti¢cial substrates on growth and prawn population structure and grading of animals before pond stocking to reduce heterogeneous individual growth and aggressive interactions. Recent studies have concentrated on combining these factors into a 'best management practices' (BMPs) production model. With these factors combined, production has increased from an average of 1000 kg ha À1 of 30 g animals to almost 3000 kg ha À1 of 40 g animals produced in research ponds in 110 days of culture. In commercial ponds, 1500^2000 kg ha À1 has been achieved in a similar period using BMPs.