Effect of food restriction on female reproductiveperformance in the redclaw crayfish Cheraxquadricarinatus (Parastacidae, Decapoda)

Abstract

Aquaculture activity has grown remarkably in thelast years, crustaceans being the most profitableproducts because of their high prices. Feeding costsrepresent a large portion of total operating costs inthe aquaculture industry. In this context, theobjective of the present study was to evaluate theeffect of food restriction on the reproductive performanceof redclaw crayfish Cherax quadricarinatus.Females at the onset of sexual maturity werestocked with males and were fed daily a formulateddiet at 1.5% (control group) and 0.5% (restrictedgroup) of their mean weight. Theexperimental period lasted 105 days. The percentageof ovigerous females and broods successfullyhatched tended to be higher in restricted femalescompared with control females, but egg volumeand weight did not differ between both experimentalgroups. However, the lipid concentration ofrematuring ovaries was lower in restricted femalesthan control females, suggesting that food restrictionaffects the amount of reserves transferred tothe ovaries during vitellogenesis. The nutritionalstate of females was independent of the amount offood provided, as reflected by similar growthparameters and biochemical composition of thehepatopancreas in control and restricted females.Based on these results, we conclude that it is possibleto reduce the feeding rate of C. quadricarinatusfemales to one-third of its original value withoutaffecting their reproductive performance and somatic growth, at least for a 105-day period. Thisfinding provides a useful tool for commercial producersto decrease production costs and improvewater quality in culture systems.