Fish meal (FM) has long been considered an essential ingredient for the formulation of shrimp feeds. Until recently, 12%FM was considered a minimum amount, below which weight gain would become reduced due to a reduction in feed intake. In order to test this perceived minimum value, an experiment was conducted on a long-term basis with 4 replicates. Four practical isonitrogenous and isoenergetic diets were formulated for Litopenaeus vannamei juveniles. Survival, weight gain, feed conversion ratio (FCR) and protein efficiency ratio were determined for 0, 6, 10 and 15% FM diets and a reference diet. Shrimp survival ranged from 84 to 86.5%. Shrimp fed a diet with 0% FM showed lower average weight and SGR compared to the other treatments (P < 0.05). FCR of shrimp fed the reference diet was significantly lower compared to the other treatments. Short-term energy budget did not differ in recovered energy (RE). Variations in RE according to FM level were expected, however, it remained low (0.12 kJ prawn − 1 day − 1) and it was not possible to discriminate among dietary treatments. Data indicate that RE was similar as evidenced by an absence of difference in weight gain among 6, 10 and 15% FM diets and the reference diet (0.98 g/wk). Growth results obtained over a long-term period and in clear water indicated the possibility for FM replacement with soybean plus canola meals.

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Populations of the alligator gar Lepisosteus spatula (also known as Atractosteus spatula) and the tropical gar L. tropicus are declining as a result of commercial and sport fisheries and habitat alteration. Aquaculture represents a short-term approach to population restoration but requires an understanding of the nutritional requirements of early life stages. This paper describes the larval development and growth rates of the alligator gar and tropical gar and identifies morphological indicators of growth and nutritional condition during early life stages. A light-colored dorsal stripe distinguished alligator gar larvae (23-130 mm total length [TL]), whereas tropical gar larvae (22-60 mm TL) could be identified by a pair of brown and yellow lines on the flanks. Larvae of both species adhered to vegetation through the fourth day after hatching (DAH) and began to swim and feed on the fifth DAH. The growth rate of alligator gar larvae was 1.55 mm/ d until 10 DAH and 5.06 mm/d thereafter until 15 DAH, when alligator gar larvae averaged 48.6 Ϯ 1.5 mm TL. The growth rate of tropical gar larvae was 1 mm/d until 15 DAH, when these larvae averaged 20.5 Ϯ 0.7 mm TL. A stepwise discriminant analysis suggested that snout length, body depth at the pectoral fins, caudal peduncle depth, and snout width at the anterior margin of the eyes were the best morphometric characteristics for evaluating the growth of gar larvae. Starved larvae of both species stopped growing by 8 DAH, suggesting that yolk reserves were exhausted by that time and indicating a mixed nutrition phase (i.e., lecithoexotrophic) between 5 and 8 DAH.Stepwise discriminant analysis determined that caudal peduncle depth, head width, and preanal depth measured after 8 DAH were the best morphometric indicators of the nutritional condition of gar larvae. Relatively dark body pigmentation also characterized starved larvae.

The freshwater Fish Invasiveness Screening Kit (FISK) has been applied in 35 risk assessment areas in 45 countries across the six inhabited continents (11 applications using FISK v1; 25 using FISK v2). The present study aimed: to assess the breadth of FISK applications and the confidence (certainty) levels associated with the decision-support tool's 49 questions and its ability to distinguish between taxa of low-to-medium and high risk of becoming invasive, and thus provide climate-specific, generalised, calibrated thresholds for risk level categorisation; and to identify the most potentially invasive freshwater fish species on a global level. The 1973 risk assessments were carried out by 70 ? experts on 372 taxa (47 of

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