Intestinal steatosis in the farm-reared sea bass Dicentrarchus labrax

Abstract

Light microscopy, scanning and transmission electron microscopy were used to study the anterior intestine of the sea bass Dicentrarchus labrax L., involved in lipid absorption. In the first part of the study, intestinal morphology of control feral fishes was described and lipid absorption through the intestinal mucosa was defined by comparing starved and fed individuals. In the second part, similar investigations were made on specimens reared on artificial food. These show injuries of the mucosa, ranging from simple impairment of enterocytic striated border to cellular necrosis and abrasion. The severity of injuries was related to the extent of lipid overloading within the mucosa. This overloadng was mainly represented by abundant lipid droplets in epithelial cells, and by the accumulation of numerous and large lipid granules in interenterocytic spaces and in the lamina propria. Possible influences of artificial feed on this digestive pathology are discussed from quantitative and qualitative points of view.