Effect of Stocking Density on Growth and Survival of 3-Month-Old Juvenile Marron,Cherax tenuimanus,Raised in a Semi-Controlled Environment

ABSTRACT

The effect of three stocking densities (3, 6, and 13 animals/ m²) on growth, survival, biomass, harvest rate, and the size distribution of 3-month-old marron, Cherax tenuimanus(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/m² was significantly lower than marron stocked at 3 and 6/m² (70.0% and 57.5%, respectively). Harvest rate of marron stocked at 6/m² was 101.3 g/m², which was significantly higher than the harvest rate of marron stocked at 3 and 13/m² (48.7 g/m² and 58.7 g/m², respectively). By the end of the trial, the densities of all treatments had decreased to the same level (2.3 to 3.0/m²). Final size frequency distribution of marron at the stocking density of 6/m² was flat and less positively skewed as compared to the 3 and 13/m²treatments. Therefore, the stocking density of 6/m² is recommended under semi-controlled environment.