Vol 45, No 4 (2019)

Various principles of organization of the blood plasma proteome are considered using the example of teleost fishes, whose lower members have albumin, while the higher members have lost it. Albumin, which creates the colloid osmotic pressure of blood plasma and is involved in lipid transport and other functions, is compared to the multifunctional potential of high-density lipoproteins (HDL), which dominate in the blood of bony fishes and probably compensate for the lack of albumin in higher Teleostei. The elements of the structural organization and functions of two proteins, that is, albumin and apolipoprotein A (as a part of HDL) that are dominant in the blood of fish, the features of the plasma proteome in marine and freshwater fishes, and the hypothesis of the evolution of the plasma proteome and a special strategy of osmoregulation in Teleostei (with the involvement of serum HDL and without albumin) are considered. Two strategies of organization of the fish blood plasma proteome are noted: on the branch that led to Teleostei an expansion of the size–compositional range of lipoproteins and an increase in the role of HDL in metabolic processes occurred; on the branch that led to Mammalia a separation of the lipid transport and osmoregulation functions occurred between lipid and albumin and an increase in the albumin content in the blood plasma.

The peculiarities of the linear growth and morphogenesis of the commercial brown alga Fucus distichus subsp. evanescens from the Avacha Bay (southeastern Kamchatka) were studied during the period from April 1 to October 7, 2017. Fucus plants were divided into five size groups (Groups 1 to 5) of five labeled plants each. The observations were conducted at spring ebb tides; we measured the length of dichotomous branches of each order regularly, one to two times per month, and determined their increase and the state of maturity of apical branches. During the period of our field observation, labeled plants formed from four to six new dichotomous branches. Moreover, the plants with only one dichotomy in April had a higher growth rate than those that had three to five dichotomous branches at the beginning of the studies. By the end of the observations, plants with one, two, three, four, and five dichotomous branches became bushes with seven, seven, eight, eight, and nine dichotomies, respectively. The absolute growth rate of the investigated plants of F. distichus subsp. evanescens varied from 23.2 to 36.7 mm per month with the maximum value of 2.33 mm per day recorded in June. Thus, Fucus displayed more active growth than previously believed. This allows us to consider these brown algae as a potential object for introduction to mariculture. Since Kamchatka representatives of the species can form several dichotomous branches during one vegetation season, the number of dichotomies is not an indicator of the age of algal plants, as was previously suggested.

Pliocardiines (Bivalvia: Vesicomyidae: Pliocardiinae) are a chemosymbiotrophic group of bivalve mollusks that are obligate for reducing environments. These mollusks house endosymbiotic thioautotrophic bacteria in their gills, which provide nutrition for the host. The ultrastructure of spermatozoa and the state of the gonads in the pliocardiine bivalve Calyptogena pacifica in June 2016 were studied. Material was collected in the Bering Sea on the slopes of the Piip’s Volcano at a depth of 466 m. The condition of the gonads indicated a pre-spawning state. Active processes of spermatogenesis and oogenesis were noted in the gonads. The mature spermatozoon has an elongated bullet-shaped head with an average length of 4 ± 0.2 μm from the tip of the acrosome to the base of the mid-piece. The mid-piece was formed by a complex of four spherical mitochondria with a diameter of approximately 0.7 μm. An electron dense material of a lipid nature was observed in the distal region of the mid-piece of the sperm. C.pacifica mature eggs are approximately 200 μm in diameter. The results are discussed in the context of the available data on the morphology of pliocardiine gametes.

A regional model is proposed for the estimation of the specific growth rate of phytoplankton in the sea surface layer using satellite data. The model is based on phytoplankton photosynthesis rate and biomass in organic carbon units. The phytoplankton photosynthesis rate was calculated based on ecological and physiological characteristics that were previously obtained for the Black Sea. The input parameters of the model are the chlorophyll concentration in the surface layer, water temperature, the intensity of the photosynthetic active radiation falling on the sea surface, the depth of the mixed layer, and the diffuse light attenuation coefficient. Seasonal variations in specific growth rate of phytoplankton were estimated for deep-water and near-Danube areas. The maximum values were found in the coastal area in May–June, the minimum values were observed in deep waters before the spring maximum of phytoplankton. The maximum and minimum values differed by a factor 5. The measured and calculated values of phytoplankton specific growth rate at individual stations and in selected extensive areas of the sea were fairly close. The model can be used for rapid estimation of the specific growth rate of phytoplankton in the sea surface layer using satellite data.

The northern elephant seal does not inhabit the waters of Russia. Encounters with this animal are rare and in most cases occur at rookeries of eared seals. The records of elephant seals from Russian waters in recent decades may be evidence of an increase in their population and expansion of the species range. This report provides summarized data on the records of northern elephant seals from waters of the Russian Far East.