Induction of somatic growth in juvenile crayfish Cherax quadricarinatus (Decapoda, Parastacidae), by ecdysone and insulin growth factor

The effect of ecdysone and IGF-1 on the somatic growth of juvenile crayfish Cherax quadricarinatus, was examined both in vitro and in vivo. After 24 h of incubating explants of abdominal muscle, protein synthesis was augmented by exposure to 0.15 μM of ecdysone, 0.02 μM of IGF-1 or the combination of both hormones. The in vivo experiments were done by feeding the juveniles a pellet food supplemented with ecdysone, IGF-1 or a combination of both hormones, at doses equivalents to those that had an effect in the in vitro experiment. Animals fed IGF-1 or IGF-1 and ecdysone enriched pellets showed a higher weight gain than controls, while no differences were detected in the case of juveniles fed pellets enriched with ecdysone alone. In close correspondence with these results, and also with the in vitro results, a significant increment in protein content was found in muscle of crayfish treated with IGF-1, alone or in combination with ecdysone. On the other hand, significant lower lipid content was found in the hepatopancreas of both groups treated with IGF-1. Our results confirm the in vivo anabolic effects of IGF-1 on crustaceans, in terms of enhancing growth and protein synthesis, therefore identifying this hormone as a potential tool for crayfish culture.

► We studied the effect of ecdysone and IGF-1 on growth of juvenile crayfish.
► Protein synthesis increased after in vitro exposure of muscle to each hormone.
► IGF-1 incorporated to diet increased both weight gain and muscle protein content.