Energetic reserves and growth of advanced juveniles of the freshwater crayfish cherax quadricarinatus, fed on an ecdysone-enriched diet

CHAULET A; CAHANSKY AV; VIAU VE; GUTIÉRREZ ML; TURCATO OLIVEIRA G; RODRIGUEZ EM

La Serena

Congreso; Mid Year Meeting, Crustacean Society 2007; 2007

Crustacean Society

The Australian redclaw crayfish Cherax quadricarinatus is currently cultured in several countries around the world. This species presents a high commercial value as well as several advantages for aquaculture purposes, such as a very good survival of adults and a relatively high growth rate at optimal, tropical temperatures (1). However, by reducing the time spent for developing the first juvenile stages, a higher productivity and lower costs of production could be achieved. As other arthropods, crustaceans have to molt to increase their size. Molting is controlled by the hormone ecdysone secreted by the Y-organ (2). Ecdysone secretion is in turn controlled by the molt-inhibiting hormone (MIH) secreted by the sinus gland at the eyestalks. Ecdysone is secreted as α-ecdysone, which is hydroxylated to the active form, 20-hydroxyecdysone (β-ecdysone), in peripheral tissues (3). Although the effects of ecdysone for molting have been intensively studied, the physiological role of low levels of ecdysone during the intermolt period is still far from being elucidated. Taken together, these preliminary results are suggesting that an anabolic effect of the ecdysone could be taking place during the intermolt period of juvenile crayfish. Ecdysone could be stimulating the accumulation of energetic organic compounds in storage tissues (mainly hepatopancreas), therefore decreasing the circulating levels of those compounds (Fig 1 and 2). Some anabolic effects of ecdysteroids such as β-ecdysone have been reported in skeletal muscle of birds and mammals (7). Utilization of this anabolic could be a relevant tool for crustacean aquaculture. Further research is needed to fully characterizing its effects.