Vol 49, No 3 (2023)

Striated muscles of the teleost fishes sometimes combine into complicated “supramuscular” complexes. In these complexes, individual muscles are connected into parallel combinations and/or in sequential series. A group of parallel muscles combines their forces to carry out a single powerful functional act. Consistently connected muscles obtain thereby an increased amplitude and speed of movements. For the described “supramuscular” complexes, the term “supermuscle” has been proposed. The paper provides an overview of the features of the structure and the function of the supermuscles of the teleost fishes heads with parallel and sequential structures. A variety of causes for the formation of muscle complexes is discussed for different taxa of Teleostei.

In our study we investigated the growth, biochemical composition, and ultrastructure of Tisochrysis lutea microalgae in enrichment culture during 30 days experiment. The number of T. lutea cells increased throughout the experiment. We noted an increase in the size and number of lipid droplets containing fatty acids and carotenoids, including fucoxanthin, in the exponential and stationary phases of their growth. It has been established that the total content of carotenoids reaches a maximum in the stationary phase and decreases in the dying phase. During the stationary phase, exocytosis is observed in cells with the release of lipid droplets. This study demonstrates the potential of the T. lutea clone MBRU_Tiso-08 from the Marine Biobank Bioresource Collection of the NSCMB FEB RAS as a raw material for domestic biotechnology aimed at the combined extraction of carotenoids (including fucoxanthin) and lipids (including docosahexaenoic and eicosapentaenoic fatty acids).

The content of Pb, Cd, Cu, Cr, Mn, Ni, Fe, and As in the muscle, mantle, and digestive glands of the gastropod mollusks Neptunea excelsior, N. behringiana, N. multistriata, and N. varicifera, as well as Buccinum verkruezeni, living near the coasts of the South-Eastern Sakhalin has been estimated. Representatives of the ge-nera Neptunea and Buccinum showed some differences in the ranges of variation and series of value sequences of trace element concentrations in the muscle. Exceeding the hygienic standard for the content of As in the hepatopancreas was found in all the studied mollusks, and in the muscle – in all, except for N. behringiana. The maximum permissible level of Cd concentration was exceeded in the hepatopancreas of N. multistriata.

The hemolymph cells of the ark clam Anadara broughtonii were examined using light microscopy, flow cytometry and gradient centrifugation. All three methods of analysis made it possible to identify two main types of cells in the hemolymph of the ark clam Anadara broughtonii – large granular erythrocytes and small agra-nular amebocytes. Erythrocytes accounted for 95.6 ± 0.9% of the total number of hemolymph cells. Erythrocytes were hemoglobin-containing cells with a great number of granules in the cytoplasm, a low nuclear-cytoplasmic ratio (NCR) and a lower intensity of cellular respiration compared to amebocytes. Amebocytes are cells of predominantly irregular shape with a high number of cells that do not contain or contain no more than 10 granular inclusions in the cytoplasm. All types of hemocytes found in the ark clam hemolymph demonstrated the same ability to spontaneously produce reactive oxygen species. For the first time, it has been shown that red blood cells of the ark clam Anadara broughtonii are capable of phagocytosis. At the same time, amebocytes absorbed on the average two times more zymosan particles (10.3 ± 0.7 pcs.), compared to erythrocytes (5.3 ± 0.1 pcs.).

The capture of a thresher shark Alopias vulpinus (TL 136.5 cm) in Peter the Great Bay (Sea of Japan) on September 5, 2022 is reported. A description of the specimen, including surface morphometric parameters, vertebraе counts, the number of tooth rows, and the number of intestinal valve turns, is presented.