Effect of stocking density on growth and survival of 3-month-old juvenile marron, Cherax tenuimanus, raised in a semi-controlled environment

摘要

The effect of three stocking densities (3, 6, and 13 animals/m~2) on growth, survival, biomass, harvest rate, and the size distribution of 3-month-old marron, Cherax lenuimanus (3.1 +- 0.1 g mean initial weight), was assessed in a 160-day trial in a recirculating system. There was no difference (P > 0.05) in specific growth rates (SGR) at the end of 160 days. Survival of marron at 13/m~2 was significantly lower than marron stocked at 3 and 6/m~2 (70.0% and 57.5%, respectively). Harvest rate of marron stocked at 6/m~2 was 101.3 g/m~2, which was significantly higher than the harvest rate of marron stocked at 3 and 13/m~2 (48.7 g/m~2 and 58.7 g/m~2, respectively). By the end of the trial, the densities, . of all treatments had decreased to the same level (2.3 to 3.0/m~2). Final size frequency distribution of marron at the stocking density of 6/m~2 was flat and less positively skewed as compared to the 3 and 13/m~2 treatments. Therefore, the stocking density of 6/m~2 is recommended under semi-controlled environment.