Quantitative fine structural diversification of red and white muscle fibres in cyprinids

Synopsis

Based on the results of investigations into the fine structure of red and white muscle of roach, Rutilus rutilus, and chub, Leuciscus cephalus (Sänger et al. 1990), analysis of axial muscle has been extended to include nine other cyprinid species. Quantitative comparisons were made of myofibrils, mitochondria, lipid and subsarcolemmal cytoplasm in relation to muscle fibre type and species. A comparison of these variables between the species shows that for red fibres there are significant differences in all measured variables in at least some cases. The most striking difference is in lipid content, with Danube bleak, Chalcalburnus chalcoides mento, having the highest amount. For white fibres, there were significant differences only in intermyofibrillar mitochondria and myofibrils, which were most significant in Danube bleak. As a preliminary study,intermediate fibres have been examined qualitatively and compared with the other two fibre types using the above mentioned variables. The results allow cyprinids to bearranged according to their scores from the different measurements. These groupings are discussed in relation to the different life-styles of the fish.