卷 43, 编号 4 (2017)

This review examines the state of knowledge of microphytobenthos of the Sea of Azov. The insufficient number of floristic studies and the almost complete lack of quantitative data on populations and communities of microalgae in different marine ecotopes demonstrate the relevance of studying the microphytobenthos.

A new species of nephtyid polychaete habiting from the sublittoral to the continental slope (depth 14–500 m) of the Northwest Atlantic is described. The most significant characters of adults are: interramal parts of the preacicular lobes are wrapped around the acicular lobes; interramal parts of the neuropodial postacicular lobes and interramal parts of the postacicular rows of neurochaetae wrapped around the acicular and preacicular lobes; interramal parts of the postacicular rows of notochaetae wrapped around the acicular and preacicular lobes and covered by the bases of the notopodial cirri. Comparison with other species of the genus is provided.

The article provides descriptions of the new genus and species of parasitic copepods: Chauvanium chauvani gen. et sp. nov. from Alepes melanoptera Swainson, 1839 (Perciformes: Carandidae), Sagum vietnamiensis from an unidentified fish species, and Hatschekia hanguyenvani from Lutjanus (Perciformes: Lutjanidae).

The dynamics of the size–age composition and growth of the mud shrimp Upogebia major in the upper sublittoral area of Vostok Bay (Peter the Great Bay, the Sea of Japan) were investigated in 2015 and 2016. Ovigerous females were found in April and May after the disappearance of the sea ice cover. Egg laying occurs only once during the breeding season. Hatching of larvae is observed in May, while in July the bottom population is replenished by a cohort of fast-growing young individuals that reach a body length of 43–44 mm during the first season of growth. In the third year of life, the females lay eggs for the first time at a body length of more than 73 mm. The females and males grow at the same rate; their growth can be approximated by a Bertalanffy equation of the form L_t = 118.4 [1–e^{–0.5627 (t + 0.5305)}]. The mud shrimp population consisted of 1–4- and, possibly, 5-year-old individuals 9–117 (females) and 8–116 mm (males) in body length. The specific features of the breeding, growth, and reproduction of the local populations of U. major are indicative of good adaptation of this species to the environmental conditions in Peter the Great Bay, which contributes to sustaining the biodiversity of the coastal zone in the region.

The environmental changes in the southern part of the Chukchi Sea over the last 2300 years (two warmings during the ~262 BC–630 AD and ~630–1300 periods AD and 1 cooling ~1300–1840 AD) were inferred from changes in the content of diatoms in sediments (per gram), the ratio of dominant species, and the ecological structure of diatom assemblages. The sediment age was determined based on the recent ²¹⁰Pb sedimentation rates at the sampling point (0.43 mm/yr) and radiocarbon dating of mollusk shells. The environmental changes in the southern Chukchi Sea that were inferred from the diatom analysis correlate with global climate changes, viz., the warming events of the early (Roman) and the middle (Medieval) Subatlantic and the cooling of the late (Little Ice Age) Subatlantic.

The spectral sensitivity and complement of the retinal photoreceptors of the Asiatic smelt from the Sea of Japan were studied by microspectrophotometry and light microscopy. Apart from rods, one type of single cones and one type of unequal double cones were found in major parts of the retina. The dominant type of the cone pattern (mosaic) is a row pattern consisting of various linear arrangements of separate single and double cones. The absorbance maxima of rods and a majority of singe cones and double cones equaled 516, 425 and 514/565 nm, respectively. It has been established that all of the pigments are based on retinal. The findings are compared with data on the osmerid retina from the literature and discussed with respect to the adaptations to light conditions, peculiarities of behavior, and seasonal migrations of smelts.

The current status of the Yesso scallop, Mizuhopecten yessoensis, population has been studied in waters of the southern part of the Far Eastern Marine Reserve. The maximum population densities of this species observed in Kalevala Bay in 2007 and 2015 were 0.50 and 0.56 ind./m², respectively. In the bays and off the semi-open shores, the mean population density was higher than in open waters. The number of Yesso scallops in the studied part of the reserve (1.3 million ind.) is equivalent to that in 2007 (1.2 million ind.); the difference between the population density values in 2007 and 2015 is statistically insignificant at the 5% level of significance. The total number of M. yessoensis in Peter the Great Bay is estimated at 4 million ind.; at least one-quarter of the population inhabits the southern part of the reserve.

According to previously obtained data, seabird colonies, as a biotic factor, exert a substantial influence on communities of some coastal waters around the Novaya Zemlya archipelago. In the current study, an attempt has been made to assess the degree of the impact of seabird colonies on planktonic assemblages in the coastal waters of the Kola Peninsula. A study of phyto- and zooplankton near the colony on Cape Gorodetsky (Rybachy Peninsula) did not reveal any substantial differences in the qualitative and quantitative composition of this community in comparison with the other coastal waters of the Barents Sea. The lack of influence on the coastal biota can be explained by the low abundance of birds in the colonies, as well as by the effect of the Murman Coastal Current, which carries away and disperses the biogenic matter that enters the aquatic environment with guano.

The chum salmon of the Amur River (the mainland part of the Far East) and the Poronai River (Terpeniya Bay, Sakhalin Island) are historically related to one another, as the drainage basins of these rivers are the remnants of a formerly single river system, the Paleoamur, which existed when Sakhalin Island was a part of the continent. Both river populations of chum salmon consist of the early-run and late-run ecological forms (seasonal races), which are also referred to as the summer and autumn races. They are reproductively isolated from each other due to their spawning at different times and in different types of spawning grounds. To assess the direction, pattern, and degree of divergence between these chum salmon races in the both river fragments since the Paleoamur, it is necessary to compare them using two types of traits: selectively neutral DNA markers and morphological and physiological traits, variations in which may have an adaptive value. For this, we have studied chum salmon from both rivers in terms of microsatellite DNA markers, body counts and measurements, body weight, and fecundity. Both in the Amur River and in the Poronai River, the autumn race of chum salmon prevails over the summer race in body length and weight, fecundity, number of pyloric caeca, and several other meristic traits. The intra-basin differences between the races are much more pronounced in the Amur chum salmon. The inter-race differences in microsatellites are also greater in the Amur chum salmon compared to the Poronai chum salmon. Using microsatellites, three levels of differentiation have been revealed: (1) between the basins of the Amur and Poronai rivers, (2) between the races within each of the river basins, (3) and between population samples within each race of each basin. A hypothesis is proposed that the currently existing races of chum salmon in the Amur and Poronai rivers have evolved since the breakup of the Paleoamur, and the intra-basin divergence of the races started in the Amur River earlier than in the Poronai River. An analysis of our own data and the published data suggests that the adaptation of the seasonal races of chum salmon to the conditions of their spawning grounds is determined by a complex of morphological and physiological traits, including the number of pyloric caeca, which is an adaptive and highly heritable trait associated with the incubation temperature of the water.

The article provides a description of Davidijordania lacertina (Pavlenko, 1910) with a body length of 18.0–32.0 mm TL, collected from Vostok Bay, Sea of Japan. The total number of vertebrae (119–121) and the pigment pattern on the bodies of the examined juvenile fish correspond to those of D. lacertina.