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Dietary protein source and level alters growth in neon tetras

Sealey, Wendy M., Barrows, Frederic T., Casten, Mike, Hardy, Ronald W.
North American Journal of Aquaculture 2009 v.71 pp. 320
Characidae, animal growth, animal proteins, animal source protein, aquarium fish, aquariums, crude protein, experimental diets, feed conversion, feed formulation, fiberglass, fish feeding, fish feeds, fish meal, ingredients, nutrient requirements, nutrition assessment, ornamental fish, palatability, plant products, plant proteins, plant source protein, protein sources, survival rate, tanks, weight gain
Nutritional studies for aquarium fishes like the neon tetra Paracheirodon innesi are sparse in comparison with those for food fish. To determine the optimum dietary protein level and source for growth of neon tetras, diets were formulated to contain 25, 35, 45, and 55% dietary protein from either marine animal protein or plant protein sources in a 432 factorial treatment design. Neon tetras (initial weight, approximately 0.12 g) were reared in 5-L fiberglass tanks (25 fish/tank, 3 tanks/diet) in a freshwater recirculating system. Fish were hand-fed the experimental diets three times per day for 12 weeks. Average weight gain of neon tetras fed diets with marine protein sources was significantly higher than that for fish fed diets based on plant proteins. Fish fed diets containing 45% or 55% crude protein had significantly greater weight gain than did fish fed 25% crude protein from either protein source. Fish fed 25% crude protein from either source had a significantly higher feed conversion ratio than did those fed 45% or 55% crude protein. Survival ranged from 71% to 84% and was not significantly altered by dietary protein source or level. No significant interactions between dietary protein source and level were found for any of the response variables. As the price of fish meal continues to increase, the formulations of feeds for food fish will probably contain lower amounts of fish meal and higher amounts of plant protein products. If a similar trend occurs for ornamental fish diets, further refinement of nutritional requirements and assessment of palatability of feed ingredients for neon tetras and other aquarium species will be required.