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Total replacement of fishmeal using marine co-product meals in the diets for white shrimp Litopenaeus vannamei and its effects on growth, feed utilization and muscle HUFA and sterol composition were assessed in a 45-day feeding trial with juvenile shrimp (0.32 g mean initial weight). Eight dietary treatments were tested: a control diet containing fishmeal ( FM), a commercial shrimp diet as external reference and six diets where the FM in the control diet was totally replaced by pen shell scallop viscera ( Pinna rugosa), squid viscera ( Dosidicus gigas) or whole chub mackerel ( Scomber japonicus) meals, produced by two methods: (i) cooking followed by grinding and drying and (ii) grinding followed by drying. Survival in all treatments was above 92%, except in the commercial diet (77%). The growth response, feed utilization and chemical composition of shrimp varied among the treatments and were affected in different ways by the by-products and the meals preparation process. Growth and feed intake were significantly higher in shrimp fed diets containing cooked-dried squid and pen shell scallop viscera meals, and whole mackerel meal produced by grinding followed by drying. Muscle fatty acid profiles were improved for human consumption when these ingredients were used, compared with the diets containing FM. [ABSTRACT FROM AUTHOR]

Phosphorous (P) and nitrogen (N) residuals from Litopenaeus vannamei and N and P retention by L. vannamei were studied at three protein levels and with two protein sources: fish meal with plant protein ( AVD) and plant protein with squid meal as an attractant ( VD). A protein retention bioassay began with shrimp that were 1.5-2.5 g, and nutrient release bioassays were conducted with shrimp of two sizes (4.5 and 8.5 g). Both bioassays were conducted at: 30 ± 0.5°C, [O2] > 4 mg L−1, and 38 UPS. Total P residuals were significantly higher for AVDs than for VDs ( P < 0.05), particularly those with a high dietary protein level. The particulate P fraction was the predominant form of P. Total N and inorganic dissolved N, mainly in ammonia form, significantly increased ( P < 0.05) with dietary protein level and shrimp size, regardless of the protein source. VDs resulted in significantly greater P retention ( P < 0.05) than AVDs, without significantly affecting growth rates or survival. P retention as well as N retention decreased with increasing protein supplementation level, independently of the protein source used ( P > 0.05). This study shows that the substitution of fish meal with plant protein (soybean meal and wheat flour) improves P retention in L. vannamei. [ABSTRACT FROM AUTHOR]

Two trials were conducted to determine the efficacy of fish fed live yeast Debaryomyces hansenii strain CBS 8339 on immune and antioxidant systems in leopard grouper Mycteroperca rosacea infected with Aeromonas hydrophila. Juveniles (12±0.5 g) were fed with a control diet or a D. hansenii-supplemented diet (106 colony-forming units per gram) for 5 weeks. The live weight of fish was registered on a weekly basis. After 4 weeks, fish from each treatment were immunocompromised with pathogenic A. hydrophila and further fed for 1 week in order to evaluate the effect on immunological and antioxidant parameters. Generally, the results showed enhanced growth performance in fish fed the diet containing yeast compared with the control. Addition of live yeast had no significant effect on the immunological parameters after 4 weeks of feeding. However, post infection with A. hydrophila fish fed the yeast-supplemented diet resulted in a significant increase in the levels of plasmatic immunoglobulin M. Superoxide dismutase and catalase (CAT) activities were significantly higher in the yeast group. In this fish, CAT and heat shock protein 70 genes were up-regulated before and after infection of A. hydrophila. The present study is the first one reporting that yeast ( D. hansenii) can enhance immunity and resistance against A. hydrophila. [ABSTRACT FROM AUTHOR]

The article presents information on larvae and juvenile production of the leopard grouper, Mycteroperca rosacea. The leopard grouper Mycteroperca rosacea is distributed throughout the Gulf of California to Jalisco,Mexico. As a First step in developing juvenile leopard grouper production, research on hormone induction of spawning and on larval growth until the first feeding of leopard grouper was conducted.The SGR of leopard grouper juveniles with an initial weight of 3.9 g was similar to growth results of Nassau grouper.