Effects of temperature upon ablation-to-molt interval and mortality of red swamp crawfish ( Procambarus clarkii) subjected to bilateral eyestalk ablation

The shortening in molt interval and induced mortality due to crawfish eyestalk ablation are the main factors that need to be evaluated for the application of ablation technology in commercial softshell crawfish production. Effects of temperature on the ablation-to-molt interval and mortality of ablated red swamp crawfish ( Procambarus clarkii) were investigated in laboratory scale recirculating culture systems in two studies conducted in separate years. Higher temperatures resulted in a shorter molt interval but higher mortality. With temperatures that ranged from 15 °C to 30 °C, the mean ablation-to-molt interval was reduced from 18.4 days to 6.4 days for immature crawfish and from 26.3 to 8.3 days for mature crawfish, respectively. Mortality, on the other hand, increased from 24.8 to 38.6% for immature crawfish and from 36 to 47% for mature crawfish, respectively. For immature crawfish, the majority of the mortality occurred within several days following ablation; but for mature crawfish, additional mortality occurred in molting. In both studies, the mortality varied among experiments, suggesting that other factors also played important roles in determining mortality.