Brown trout is a common type of fish grown for consumption in open and
flowing fish ponds on the rivers of Bosnia and Herzegovina. We conducted
this study during three seasons (spring, summer and autumn) to obtain
a complete picture of the morphological and histological characteristics
of selected trout tissues. The physicochemical characteristics of the
water from the Pliva River near Pljeva and the fish pond where intensive
breeding of trout is carried out were analyzed. These analyses have shown
that there are no major deviations in water quality and that the water in
the pond is of excellent quality. A total of 90 trout were harvested during
all three seasons and their morphometric characteristics were determined
by analyzing ten parameters. After the dissection of all individuals,
histological and stereological analysis was performed to compare the
tissues of the liver, stomach, gills and muscles. These analyses showed
significant differences in the histoarchitecture of selected trout tissues
from the pond compared to the river. Liver tissue had altered hepatocyte
shape and presence of adipocytes; stomach tissue had stronger mucosa
and weaker muscle layer; gill tissue had lower respiratory lamellae; while
muscle tissue had a significant presence of adipose tissue in brown trout
living in the fish pond compared to those in the river. All these changes
are due to the quality of commercial feed and the inability to move freely.
