The aim of this studywas to determine the in£uence of
the feeding regimes in Senegalese sole (Solea senegalensis)
culturedunder extensive, semi-extensive and intensive
production systems.Atotal of 254 bacterial isolates
from guts of ¢sh cultured under di¡erent production
systems and feeding regimes were tested. Biochemical
tests and genetic analyses based on the 16S rDNA sequence
analysis were conduced to identify bacterial
strains.Vibrio species were the most represented taxonomic
group in the culturable microbiota of S. senegalensis
guts tested. Particularly,Vibrio ichthyoenteri was
the most frequently isolatedVibrio species. Comparison
among diets showed a signi¢cant reduction (Po0.05)
in vibrio percentages and a higher occurrence of Shewanella
species in Senegalese soles fed polychaeta. In
addition, a major in£uence of environmental temperature
on microbiota composition was detected. Cold
temperatures brought about a change in the percentages
ofVibrio species and a higher representation of a-
Proteobacteria in both outdoor systems (extensive and
semi-extensive).The signi¢cant di¡erences between intestinal
bacterial composition in Senegalese soles fed
commercial diets and natural preys (polychaeta) reveal
the necessity to develop speci¢c optimized diets for the
intensive rearing of this ¢sh species.
