Influence of different diets on digestive enzyme activities, in vitro digestibility, and midgut gland structure in juvenile crayfish, Cherax quadricarinatus

SACRISTAN H; FERNANDEZ GIMÉNEZ A; CHAULET A; FRANCO TADIC LM; FENUCCI JL; LÓPEZ G LS

ACTA ZOOLOGICA

WILEY-BLACKWELL PUBLISHING, INC

Lugar: Londres; Año: 2015

0001-7272

This study investigated the effects of food quality on digestive enzyme activities, in vitro 25 protein digestibility, and histological traits of the midgut gland in juvenile crayfish Cherax 26 quadricarinatus. Animals of a wide weight range were fed different diets: two commercial 27 diets with high or low lipid content (HL and LL, respectively), and were compared with a 28 reference diet (RF) previously formulated for this species. Proteinase, lipase and amylase 29 activities were significantly influenced by diet and weight. Specific trypsin activity was 30 significantly higher for crayfish fed with the HL diet. Trypsin activity depended on diet and 31 weight. Protein digestibility showed that HL was the most digestible diet and RF the least. 32 The weight of the animals did not affect protein digestibility. Structural disorganization, 33 hypertrophy of B-cells, and presence of large vacuoles in R-cells were mainly observed in 34 juveniles fed with HL, indicative of malnutrition. Thus, our data suggest that the HL diet 35 would not be the most appropriate for C. quadricarinatus, while RF diet would be more 36 convenient for culture of this species.