Vol 42, No 4 (2016)

Comparative analysis provides evidence that bilateral symmetry is a primary character of Cnidaria. All anthozoan taxa are characterized by bilateral symmetry. The anthozoan pharyngeal plane is a plane of bilateral symmetry of mesenteries and, at the same time, it is a plane of bilateral symmetry of regulatory gene expression in anthozoan morphogenesis. In Medusozoa, the bilateral symmetry is replaced by radial symmetry, but some hydrozoans (for example, Corymorphidae) demonstrate bilateral symmetry. The bilateral symmetry of Cnidaria is thought to be inherited from the common ancestors of both cnidarians and triploblastic bilaterians. The secondary radial symmetry of Cnidaria evidently is a result of the adaptation to the sessile mode of life. The presence of both the marginal and labial rings of tentacles is supposed to be a plesiomorphic character of Cnidaria. In some groups of cnidarians, one of the tentacle rings may be reduced.

The pattern of the latitudinal distribution of the floristic composition and structure of the submerged vegetation cover in the western Tatar Strait (within Khabarovsk Krai) is studied using the published data and original materials. Irregularities of the floristic composition have been found within limited areas of bays in this region, where they do not form any distinct borders or gradients. In the vegetation cover, vice versa, borders and gradients have been shown to form various combinations. The specific biomasses of most of the dominant species are significantly increasing, whereas the width and depth of the vegetation belt decreases from the south to the north. Their regression lines intersect at the latitude of 50° N (Cape Syurkum). Discrete coenotic variations are manifested most clearly as well at this point, where the dominance of Saccharina japonica, observed south of the cape, changes for S. cichorioides north of it. This allows establishing the phytocoenotic border here. The revealed features correspond to the direction of the temperature gradient, as well as to the variations in topical conditions and the level of hydrodynamic load along the coast.

The features of the group linear growth of the bivalve Callista brevisiphonata were studied over a large part of its range in the Sea of Japan along the mainland coast of Russia. It was found that in the south of the species range in the Peter the Great Bay, the shell length in individuals of the same age can differ by almost 1.5 times, depending on the position of the population relative to the open sea. With propagation from south to north, trends to a decreasing growth rate and a narrowing of the range of age variation in shell length were recorded in C. brevisiphonata populations. It was shown that the clams need 5–18 years to reach their commercial size (a shell length of more than 70 mm). The observed differences in growth rate are considered in connection to the habitat environment of C. brevisiphonata.

A comparative analysis of the morphology of in vitro flattened coelomocytes of two starfish species, Aphelasterias japonica and Patiria pectinifera (Echinodermata: Asteroidea), and hemocytes of the bivalve Callista brevisiphonata (Mollusca: Bivalvia) was performed using a number of nonlinear parameters including several types of fractal dimensions and lacunarities. The visually “chaotic” shapes of in vitro flattened hemocytes and coelomocytes of the studied marine invertebrate species significantly differ in a number of nonlinear parameters. This fact allows numerical description of the morphology of hemolymph cells of the studied animals and gives grounds to assume a species specificity of the biological differences that influence the morphology of in vitro flattened cells.

The morphological features of carpospores in the red alga Chondrus pinnulatus have been studied using methods of transmission and scanning electron microscopy. Rounded mature carpospores are assembled into groups. Each carpospore is surrounded by a two-layered mucilage wall. The electron-dense cytoplasm contains numerous starch grains, fibrous vesicles, and large clusters of fibrous vesicles. The plastids have well-developed thylakoids and the cell nucleus occupies a nearly central position. The nucleolus is large and loose and is localized near the nuclear membrane. Dictyosomes, small fibrous vesicles, osmiophilic granules, and plastids are localized at the periphery. Mitochondria are arranged near the dictyosomes, plastids, and around the nucleus. A generalized scheme of the fine structure of the carpospore has been proposed for red algae on the basis of our own and literature data.

The genetic variability distribution of two mtDNA segments of chum salmon (Oncorhynchus keta) (Walbaum, 1792) and Sakhalin taimen (Parahucho perryi) (Brevoort, 1856) was examined in populations of the Sea of Japan and the Sea of Okhotsk. The values of haplotype and nucleotide variability in these species are, in general, of the same level. The dating of the divergence time of species haplotypes revealed four evolutionary periods in Sakhalin taimen and three in chum salmon. In the taimen, the first divergence time occurred approximately 430 thousand years (kyr) ago, the second 220 kyr ago, and the third 70 kyr ago. In the chum salmon, the first divergence time corresponds to 220 kyr; the second is approximately 100 kyr ago. In both species, the main portion of presently revealed haplotypes evolved over the past 50–10 kyr. Certain glacioeustatic sea level fluctuations influenced each stage of evolution history of species, contributing to their geographic isolation. Demographic population history research found that the initial stage of population growth in the taimen occurred at the time period of approximately 12 kyr ago and was apparently associated with the end of the Last Glacial Maximum. In the chum salmon, this period began somewhat earlier, 30–35 kyr ago; it has accelerated in the past 10–15 kyr. The last glaciation to a lesser extent impacted the demographics of chum salmon, probably due to the greater eurythermity and to the larger range of this species.

Harmful animal controls on spotted seals on Rebun Island have been conducted each spring since 2010 due to an increase in the number of seals and damage to local fisheries. To evaluate the influences of controls on seals, we used the numbers of haul-out sites and hauled-out seals, and photo-identification to study differences in the usage patterns of haul-out sites by seals before and after controls. As a result, two major changes were confirmed. Firstly, in spring after controls, the numbers of hauled-out seals at Northern Rebun (NR) greatly decreased, while at Bensashi (Ben) on the southern side of Rebun they greatly increased, compared to spring prior to controls. Secondly, the number of identified seals observed at both NR and Ben (NR-Ben) increased after controls, while most of the seals that changed to NR-Ben after controls were observed only at NR (NR-NR) before controls. Additionally, most of the seals using NR-Ben were observed year-round. The controls had a direct influence on reducing the numbers of seals in the controls area mainly during the period of controls. However, many seals that avoided the controls area used other haul-out sites, and the numbers of year-round-seals on Rebun increased after controls.

The seasonal dynamics in the level of fucose-containing sulfated polysaccharides (fucoidans) have been studied in three brown alga species from Peter the Great Bay, Sea of Japan: Saccharina japonica, Sargassum pallidum, and Stephanocystis crassipes. In the latter two species, seasonal variations in the fucoidan content have been analyzed for the first time. During the year, the level of fucoidan in S. japonica varied from 0.98 to 4.19% dry weight; in S. crassipes, from 2.50 to 5.23%; in S. pallidum, from 1.86 to 6.31%. The maximum amount of this polysaccharide is accumulated in algae during reproduction: in August–October for S. japonica; in June and July for S. crassipes; and in July for S. pallidum. No significant correlation has been found between the level of fucoidan in algal tissues and the annual dynamics in sea water temperature, salinity, and concentration of biogenic elements. The obtained data can be helpful in determining the time to harvest algae for fucoidan extraction.

This paper presents a description of the anatomy and photos of live specimens of the opisthobranch mollusk Smaragdinella sieboldi A. Adams, 1864 collected in Van Phong Bay (Vietnam). It is the first record of the species from the South China Sea. This species was previously recorded for the coastal waters of Japan according to a short description of the shell. The first scanning electron microscope image of the gizzard plates made it possible to refine the morphology of the gizzard plates in Smaragdinella. It has been established that S. sieboldi inhabits dead shells of the sea barnacle Tetraclita squamosa in the upper interdidal zone. Smaragdinella fragilis Bozzetti, 2008 is very similar to S. sieboldi in its shell structure and is probably a junior synonym of the species.

A juvenile specimen of the papillose lumpsucker Georgimarinus barbatus (Lindberg et Legeza, 1955) is first described and collated with juveniles of species of the close related genus Eumicrotremus.