Dietary live yeast (Debaryomyces hansenii) provides no advantages in tropical gar, Atractosteus tropicus (Actinopterygii: Lepisosteiformes: Lepisosteidae), juvenile aquaculture

Tropical gar, Atractosteus tropicus Gill, 1863, is an ancient freshwater fish that commercially cultivated in southern Mexico. Currently, there a specific diet for its culture; however, the addition of probiotics has not been investigated. The objective this study was to evaluate supplementation live yeast Debaryomyces hansenii A. juveniles on growth, productive parameters, survival, somatic index, digestive enzyme activity, and immune system gene expressions (interleukin 10, il-10 , Transforming growth factor β1, tgf-β1 β2 microglobulin, b2m ). Three experimental diets increased dose (0.5, 1.0, 1.5%; 10 14 15 16 CFU g –1 respectively) control (CD; without yeast) were designed. Daily weight gain rate higher fed with CD 0.5% D. . High activities trypsin, chymotrypsin LAP, α-amylase, as well overexpression spleen, detected feed inclusion had no positive effect aquaculture lower doses should be tested optimize diet.