Female Perch Perca Fluviatilis Research Articles

Lipid content and fatty acid composition of target tissues in wild Perca fluviatilis females in relation to hepatic status and gonad maturation

Variation in liver ultra‐structure and composition in relation to energy mobilization was investigated in female perch Perca fluviatilis from the Meuse River between August 2001 and June 2002. In April, just before spawning, the lipo‐somatic index (IF) was 0·3%, the gonado‐somatic index (IG) was 28% and the total lipid content of the liver was 2·53%. The average areas of lipid droplets and mitochondria were 0·05 and 0·06 μm2, respectively. Glycogen supply reached 7·9% of the total area of the hepatocyte. During the sexual resting period, females accumulated energy in perivisceral fat and in the liver to reach 1·6%IF and 4·85% of liver lipid content in August with lipid droplets average size of 0·09 μm2 and glycogen average area of 15%. Liver cells contained a weakly developed rough endoplasmic reticulum (RER) and a great number of small mitochondria (average size 0·02 μm2). The IG was 0·6% at this time. During the whole annual cycle, the average lipid content of female liver never exceeded 3·9 ± 1·9%. The concentration of docosahexaenoic (DHA), linolenic and linoleic acids increased in mature gonads while linolenic and linoleic acids decreased in the liver during the same period. Fatty acid composition of muscles of perch was characterized by a high content of DHA.