COMPOSITION AND BIOELECTRICAL ACTIVITY OF LATERAL MUSCLES IN HARENGULA HUMERALIS

The chemical composition of the white and red lateral muscles of the clupeid fish Harengula humeralis (Cuvier) was investigated; water, protein, nonproteic nitrogen, lipid and glycogen content were determined. Comparison was made with the liver in regard to lipids and glycogen. Fractionated protein extractions were performed, with a view to separate sarcoplasmic, myofibrillar and stroma proteins. The following results were obtained: the red muscle contains less water, more glycogen and more lipids than the white muscle; the lipid content of the former is approximately the same as that of the liver and the glycogen content is greater per unit of tissue mass; the total glycogen content of the red muscle tissue is about 12 times greater than that of the liver (based on literature data, a correlation is established in this respect with the ecology of different fish species); the red muscle contains significantly more sarcoplasmic proteins than the white one. The conclusion is drawn that the lateral red muscle is the main storage tissue for energy reserves of the musculature in pelagic fishes, and that its main role in the organism is a metabolic one. Attempts were made to record action potentials from the 2 muscles, but the true origin of those recorded from the red muscle was not clear. © 1969 Springer-Verlag.