Effects of Dietary Lipid Levels on Growth, Survival, and Molting of Yearling Narrow Clawed Crayfish, Astacus leptodactylus

Abstract

The influence of dietary lipid level was evaluated on growth, survival, and molting of yearling narrow clawed crayfish, Astacus leptodactylus. Yearling crayfish were fed five isonitrogenous diets (35% protein), formulated to contain 4%, 7%, 10%, 13%, or 16% lipid. Crayfish (10.1 ± 1.6 g) were reared for 56 days in 60-L fiberglass tanks at 23 ± 1.7 °C, with flow-through water and continuous aeration. At the end of the trial, crayfish fed 13% lipid had the highest weight gain and specific growth rate, significantly different from crayfish fed 4% and 7% lipid (p < 0.05). Crayfish fed 13% lipid had a significantly higher survival rate (86.7%) than the animals fed 4% lipid (71%) (p < 0.05). Molting was not affected by lipid level (p > 0.05). We recommend 13% dietary lipid level for optimum growth and survival of Astacus leptodactylus in intensive cultivation.

Keywords:

• Narrow clawed crayfish
• Astacus leptodactylus
• lipid
• nutrition
• growth
• survival
• molting

Acknowledgments

We are grateful to our colleagues in Inland Waters Aquaculture Research Centre for their kind help. We are also indebted to the staff of the Sefidroud Fisheries Research Station.