LAUSR

Abstract The effect of extrusion process in aquafeeds for juvenile totoaba ( Totoaba macdonaldi ) on the microbiome diversity from four different intestinal sections and overall growth performance was evaluated. The extrusion process clearly improved the protein efficiency ratio (PER) and the apparent digestibility coefficient (ADC) compared to the modified extruded diet (MED) without pressure and high temperature; demonstrating the advantage of the use of extrusion technology. After 17 days of feeding, the microbiome analysis revealed that the taxa relative abundance at the phylum level in the four gut sections was modified according to the dietary treatment. Vibrio , Photobacterium , and Shimia , colonize the intestine of totoaba fed with extruded diet, while the genus Ruegeria was observed almost at constant levels in both dietary treatments, in most of the intestinal sections. The latter is known to promote the fish health. This work demonstrates that extrusion processes affect the intestinal microbiome and enhances the performance of fish diets.