Dietary protein source and level alters growth in neon tetras.

Authors: SEALEY, WENDY - University Of Idaho; Barrows, Frederic; CASTEN, M - University Of Idaho; HARDY, R - University Of Idaho

Submitted to: North American Journal of Aquaculture
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 4/7/2009
Publication Date: 7/15/2009
Citation: Sealey, W.M., Barrows, F., Casten, M., Hardy, R.W. 2009. Dietary protein source and level alters growth in neon tetras. North American Journal of Aquaculture 71: 320-325. 2009.

Interpretive Summary: Nutritional studies for aquarium fish like the neon tetra are few in comparison with study done using food fish. To determine the optimum dietary protein level and source for growth of neon tetras, diets were formulated to contain different levels of dietary protein from either marine animal protein or plant protein sources. Neon tetras Paracheirodon innesi Myers (approximately 0.12 g initial weight) were reared in five- liter fiberglass tanks (25 fish/tank; three tank/diet) in a fresh-water recirculating system. Fish were hand fed the experimental diets three times per day for twelve weeks. Average gain of neon tetras fed diets with marine protein sources was significantly higher than that of fish fed plant protein-based diets. Fish fed diets containing 45 or 55% crude protein had significantly greater weight gain than fish fed 25% crude protein from either protein source. Fish fed 25% crude protein from either source had significantly higher feed conversion ratio than 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 likely 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.

Technical Abstract: Nutritional studies for aquarium fish like the neon tetra 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 4 X 2 factorial treatment design. Neon tetras Paracheirodon innesi Myers (approximately 0.12 g initial weight) were reared in five - liter fiberglass tanks (25 fish/tank; three tank/diet) in a fresh-water recirculating system. Fish were hand fed the experimental diets three times per day for twelve weeks. Average gain of neon tetras fed diets with marine protein sources was significantly higher than that of fish fed plant protein-based diets. Fish fed diets containing 45 or 55% crude protein had significantly greater weight gain than fish fed 25% crude protein from either protein source. Fish fed 25% crude protein from either source had significantly higher feed conversion ratio than 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 likely 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.