Aspartate- and alanine-aminotransferase in early development of keta

We studied the activities of the marker enzymes of physiological state and adaptive reactions, aspartate and alanine aminotransferases, in early development of the keta Oncorhynchus keta. Aspartate aminotransferase with pH optima 6.8, 7.0, 7.6, and 8.0 and alanine aminotransferase with pH optima 7.0, 7.4, 7.6, 7.8, 8.0, and 8.2 were found in the eggs, larvae, and fry. The succession of enzymes with different pH takes place during ontogenesis, as well as stage specific changes in their activity. The maximum enzymatic activity was recorded in the larvae during their rise for "afloat." A correlation was established between the dynamics of enzymatic activity and soluble nitrogen and amine nitrogen contents.     

The state of gonads of resident sockeye salmon <Emphasis Type="Italic">Oncorhynchus nerka</Emphasis> from the Tolmachev Reservoir

Morphology of gonads and structure of sex cells in females and males of the resident sockeye salmon Oncorhynchus nerka—kokanee—from Tolmachevskoe Reservoir are investigated. Anomalies in structure of sex cells and structure of oocytes are found. Partial or mass resorpbion of cells in the ovaries of males and testes of males is found, leading to sterility of gonads. The relationship between anomalies found in structure of the sex system of kokanee, changes in biological parameters of fish and the increase of the population abundance is discussed.     

New data on biology and distribution of Sakhalin sturgeon Acipenser mikadoi

Our own and archival materials on biology, marking, migrations, and distribution of Sakhalin sturgeon Acipenser mikadoi were analyzed. It was shown that Sakhalin sturgeon dwells not only in Tumnin River and Datta Bay of Khabarovsk krai but also in Bay Viyakhtu and the Viyakhtu River of Sakhalin oblast. Evidence on the length, weight, and stage of gonad maturity of individuals caught in 1990?C2011 is provided. It was established that juveniles of Sakhalin sturgeon perform autumn migration from Gatta Inlet to the lower reaches of Tumnin River.     

Aspartate and Alanine Aminotransferases in Early Development of the Keta

We studied the activities of the marker enzymes of physiological state and adaptive reactions, aspartate and alanine aminotransferases, in early development of the keta Oncorhynchus keta. Aspartate aminotransferase with pH optima 6.8, 7.0, 7.6, and 8.0 and alanine aminotransferase with pH optima 7.0, 7.4, 7.6, 7.8, 8.0, and 8.2 were found in the eggs, larvae, and fry. The succession of enzymes with different pH takes place during ontogenesis, as well as stage specific changes in their activity. The maximum enzymatic activity was recorded in the larvae during their rise for afloat. A correlation was established between the dynamics of enzymatic activity and soluble nitrogen and amine nitrogen contents.     

Cell culture and karyotype of Sakhalin sturgeon Acipenser mikadoi

A cell culture of rare and threatened species of Sakhalin sturgeon Acipenser mikadoi was established from a fragment of the pectoral fin and neighboring tissues. Initially, the culture consisted of different cell types including typical fibroblasts as well as cells of epithelial origin, myofibroblasts, etc. After approximately five passages, the culture largely consisted of cells with fibroblast morphology. Under normal culture conditions, these cells grew for more than one year at a constant rate and passed about 80 population doublings. In the absence of serum, cells entered the state of proliferative quiescence (G₀-state). When cultured without medium replacement for a long period of time, cells fused to form myofibers of about 1 cm in length. These myofibers could branch and acquired cross striation with time. About forty days after myofibers emerged, they degenerated, lost their shape, detached from the substrate, and finally died. The induction of adipogenic differentiation arrested cell proliferation and introduced lipophilic inclusions formed in a minor fraction of cells. The number of these inclusions was low, and cells with inclusions demonstrated various morphology distinct from typical adipocytes. The induction of osteogenic differentiation gave rise to cells that produce mineralized extracellular matrix and bone nodules. Chromosome analysis revealed a set of chromosomes typical for “high chromosome” sturgeon species. The variation in the chromosome number was very high (mean, 247 ± 33; modal value, 248). The analysis involving AT- and GC-specific fluorochromes has demonstrated that the telomeric and centromeric regions of all chromosomes are enriched in GC content. The distribution of AT- and GC-rich sequences along the chromosomes was heterogeneous. Long chromosomes were preferentially stained by the AT-specific dye, whereas small chromosomes demonstrated brighter fluorescence after 7-amino-actinomycin D staining; in particular, several small chromosomes fluoresced extremely brightly. This work is the first report of cell culture and karyotype analysis of Sakhalin sturgeon.     

Physiological and biochemical studies of fish functional homeostasis

Stages of formation and development of physiological and biochemical studies of fish in Russia have been described. Main directions of studies and biochemical markers used for the assessment of the functional state of fish in natural populations and aquaculture have been described.