Abstract This paper reports the first occurrences of anadromous fish of the cyprinid genus Tribolodon infected with the common parasitic tapeworm Ligula intestinalis. In the autumn of 2017 and in the summer of 2018, the plerocercoids of Ligula intestinalis were found in the body cavities of two Far Eastern redfin Tribolodon hakonensis (Gunter, 1880), which were caught in the Razdolnaya River in Primorsky

Abstract This paper describes the pelagic larvae of the bittersweet clam Glycymeris yessoensis G. B. Sowerby III, 1889 (Bivalvia: Glycymeridae) from the Vostok Bay (Peter the Great Bay, Sea of Japan). Distinctive features of the morphology of the larval shell, including structure of the hinge system, as well as size parameters of the larval shell and their ratio, are presented. The period of occurrence

Abstract The amount of structural and storage lipids and the composition of fatty acids (FA) in the symbiotic hydroid coral Millepora dichotoma were determined monthly throughout the year. In the first half of the year, the hydrocoral actively accumulated lipids, as indicated by a twofold increase in the content of reserve lipid classes of (waxes, triglycerides, and monoalkyl diacyl glycerides) concurrent

Abstract This review paper considers the features of the biology of cyanobacteria, their role as photosynthetics, nitrogen fixers, and producers of biologically active substances, as well as the distribution of these microorganisms in various marine ecosystems. The symbioses of marine cyanobacteria with a wide range of eukaryotic organisms are discussed.

Abstract The distribution and size composition of the gastropod Boreotrophon candelabrum in Vostok Bay of the Sea of Japan were investigated in 2014–2019. Mollusks occurred on different bottom types and biogenic substrates, except clean washed sands of open coves and wave-exposed rocky–boulder shores. The highest abundance of B. candelabrum was observed at the head of the bay, where the density and

Abstract The effects of Zn on two mysid, two copepod, and one decapod crustacean species from Peter the Great Bay are studied. Experiments have shown the lowest median lethal concentrations (LC50) in the case of a 48-h exposure for juvenile mysids (221 μg Zn2+/L) and the highest concentrations for juvenile grass shrimp (11 309 μg Zn2+/L). The relationship of toxicoresistance with species-specific features

Abstract An inventory of macrophytic algae on the Con Dao Islands (Vietnam) in the South China Sea (8°38′ N, 106°41′ E) was carried out for the first time by Vietnamese and Russian phycologists from 1986 to 2008. Algae were collected in different years of this period. The first collections of marine algae from the Con Dao Islands were obtained in 1986 in the framework of the Soviet–Vietnamese expedition

Abstract This article provides an overview of the species composition of the phylum Nemertea in the Far Eastern seas of Russia. The list of nemerteans includes at least 200 species from the classes Palaeonemertea, Pilidiophora, and Hoplonemertea. Many of the species proved to be new to science; most of them remain undescribed. Currently, the use of gene markers is often the only approach to discriminating

Abstract A comparative analysis of the current content of petroleum hydrocarbons in various components of the ecosystem was performed to assess the ecological state of the southeastern part of the Onega Bay (White Sea) that suffered from a spill of fuel oil in 2003. The analysis showed relatively low levels of petroleum hydrocarbon concentrations: from 0.34 to 4.55 mg/kg, with a median of 1.41 mg/kg

Abstract Results of our study show that juveniles of the mangrove red snapper are found all year round from the Cua Dai river mouth to Cam Kim upstream of the Thu Bon estuary, with no clear patterns of distribution between months. Variability in recruitment of juvenile fish of ≤50 mm TL was observed from June until February, and the youngest fish (≥18 mm TL) were found in mid-June. Adult mangrove red

Abstract Until recently, it has been believed that only one cetacean species of the genus Berardius, the Baird’s beaked whale (Berardius bairdii Stejneger, 1883), inhabits the northern Pacific Ocean. However, a genetic analysis of tissue samples and morphometric data provide convincing evidence for the existence of a previously undescribed Berardius species sympatric to Baird’s beaked whale, which

Abstract In the course of floristic studies, we succeeded in finding Asterocolax denticulatus (Delesseriaceae: Ceramiales: Rhodophyta) in the Pacific waters near the coast of Kamchatka for the first time. This alga is an adelphoparasite that colonizes other algae of the family Delesseriaceae. The studied species is briefly characterized and illustrated and its distribution range is determined.

Abstract Parasites in 61 individuals of eight species of coral reef fish (Caracanthus maculatus, Scorpaenodes sp., Sebastapistes cyanostigma, Gobiodon unicolor, Paragobiodon modestus, P. echinocephalus, Pseudocheilinus hexataenia, and Halichoeres sp.) were studied in April–May 2012–2014 and November 2017. All studied fish were symbionts of corals of the genera Acropora and Pocillopora. The parasites

Abstract The ecological, genetic, and temporal intraspecific differentiation between populations of anadromous fishes of the genus Oncorhynchus is analyzed. It has been shown that the stability of the structure of exploited stocks and the maintenance of their abundance at an optimally high level can be provided by taking the population organization of fish during fishing operations into account. A

Abstract The quantitative dynamics of coelomic fluid cells of Eupentacta fraudatrix (Djakonov et Baranova, 1958) were studied by flow cytometry within a day after evisceration. A differently directed dynamics pattern was noted among groups of poorly differentiated juvenile cells and differentiated cells during regeneration. The juvenile coelomocyte fraction increased, while the content of differentiated

Abstract The Sea of Azov is a part of the Mediterranean basin and is the most continental sea in the world. But the phycological studies of the Sea of Azov were irregular. To assess the ecological safety of sea water, it is important not only to determine the presence of toxigenic species in the flora, but also to confirm the presence of strains capable of synthesizing toxins. The strain Nostoc linckia

Abstract Life cycle, population dynamics, growth, and annual production of Ecrobia maritima (Milaschewitsch, 1916) associated with the eelgrass Zostera noltei bed in the southern part of the Romanian Black Sea coast were investigated. Monthly quantitative random samples were taken from June to October 2015 and the collected snails of E. maritima were counted, measured, and weighted. The mudsnail E

Abstract In northern Primorsky Krai, males of the Siberian lumpsucker Eumicrotremus asperrimus (Tanaka, 1912) with much reduced or missing bony tubercles occur almost all along the coastline. The lack or significant reduction of bony tubercles in males is a secondary sexual characteristic of this species indicating that such males can participate in breeding. Three main stages are distinguished in

Abstract It was shown for the first time that the red alga Palmaria palmata (Linnaeus) F. Weber et D. Mohr, 1805 not only retained its physiological activity under the conditions of moderate pollution of the seawater with diesel fuel, but also exhibited a pronounced ability for sorption and destruction of petroleum products. The content of diesel fuel components in seawater decreased simultaneously

Abstract The present review summarizes information available in the published literature on the distribution of disseminated neoplasia, or malignant leukemia (leukemia-like cancer), in populations of several bivalve species. This disease of marine Bivalvia has long been known; currently (with the development of molecular-genetic methods) its etiology is associated with retrotransposons that can be

Abstract A morphological description of the rare deep-sea skates Bathyraja fedorovi, B. andriashevi, and B. tzinovskii from the northwestern Pacific Ocean is presented and data on their biology are considered. The structures of the neurocranium, scapulocoracoid, and pterygopodia are described; data on the number of abdominal and caudal vertebrae, rows of teeth, and coils of the spiral valve in the

Abstract It has been found that cell volumes of the Synechococcus sp. WH5701 strain of cyanobacteria, as well as the intracellular contents of chlorophyll a and C-phycocyanin, did not depend of the spectral qualities of light. Chlorophyll a specific light absorption coefficients by pigments at wavelengths of 438 and 678 nm in cells adapted to blue light were higher than in cells adapted to white light

Abstract The seasonal accumulation of the amnesic toxin domoic acid (DA) in the tissues of two commercial species of bivalves from Vostok Bay (the Sea of Japan) was assessed for the first time. The concentration of domoic acid in the tissues of the Pacific mussel Mytilus trossulus varied from 0.003 to 0.1 mg/kg during the period between October and February, and in the scallop Mizuhopecten yessoensis

Abstract Zinc ions and nano-sized zinc oxide had an embryotoxic effect on the sand dollar Scaphechinus mirabilis (Agassiz, 1864) at concentrations of 50–100 μg/L and completely inhibited larval development at concentrations of 200–400 μg/L. The effective concentrations (ЕС50) that caused disturbances of the fertilizing capacity of sperm and larval development of S. mirabilis were 490 ± 16 and 29 ±

Abstract The osteological description of the ocular head region and the pectoral girdle (using alizarin-stained preparations) of Ipnops agassizii Garman, 1899 (family Ipnopidae) was made based on material collected from bathyal and ultra-abyssal depths (3020–5410 m). A detailed description of the axial skeleton is provided and features of the fin skeleton are analyzed (using X-ray images). The morphological

Abstract The body size and weight characteristics were analyzed and the morpho-physiological condition of the system of internal organs was studied in wild juvenile pink salmon caught from five rivers during downstream migration, as well as in hatchery-reared juveniles collected prior to release from all 22 salmon hatcheries of Sakhalin Oblast where they were produced in 2016 and 2017. It was found

Abstract The karyotype of the brightbelly sculpin Microcottus sellaris (Gilbert, 1896) (family Cottidae) from the Sea of Japan and Sea of Okhotsk has been studied for the first time. The karyotype is stable; it includes 42 chromosomes (2 metacentric, 2 submetacentric, 32 subtelocentric, and 6 acrocentric chromosomes); the number of chromosome arms is 46. A comparative analysis of the basic karyotype

Abstract The properties of polyphenol extracts from marine brown algae of the families Laminariaceae, Alariaceae, Arthrothamnaceae, Costariaceae, Сystoseiraceae, and Fucaceae were studied. The release of polyphenols from algae was determined by the species affiliation and depended on the nature of the extractant. According to the content of total polyphenols and antioxidant activity, the maximum effect

Abstract The brown endophytic alga Laminariocolax aecidioides (Ectocarpales: Chordariaceae) growing in Undaria pinnatifida was found in Ussuriisky Bay (Peter the Great Bay, Sea of Japan) for the first time. This finding is the first record of the species in the Russian Far-Eastern seas. This paper presents the morphological features of L. aecidioides in nature and in a free-living culture, as well

Abstract The combination of a fractal formalism with linear methods of image analysis is the basis of a statistically reliable description of the morphology and classification of forms that are irregular from the point of view of Euclidean geometry, such as in vitro flattened amoeboid cells. We have developed a classification algorithm that is based on the morphological characteristics of immune cells

Abstract The long-term series of data on fish catches obtained in the fishery industry of Russia allow objective evaluation of the dynamics of the development of the industry in general, as well as assessment of the statistical characteristics of production. The results of an analysis of catches for 2005–2017 are used to determine the general trends in the development of fisheries for each of the fishery

Abstract Two different viewpoints on the factors that limit the abundance of Pacific salmon in the sea and ocean phases of their life history are compared. According to traditional notions, food resources in sea and ocean epipelagic biotopes are limited and there is a severe competition for food between different species of the genus Oncorhynchus, which is particularly exhibited by the pink salmon

Abstract This article continues the discussion about the limiting influence of climate conditions on the dynamics of Pacific salmon abundance and on the status of biological resources in the Far Eastern seas. The conclusion that the multifactor impacts of climatic and hydrological conditions on populations and communities cannot be described only by climatic indices and sea surface temperature anomalies

Abstract A method for rapid quantification of escapement of Pacific salmon spawners into the Kamchatka River catchment basin and the mathematical models for assessment of Pacific salmon spawners, escapement through a river cross section have been developed based on data from the integrated monitoring of their escapement dynamics including aerial observations, hydroacoustic surveys, and test drift-net

Abstract The chum salmon in the Amur River basin is represented by two races, that is, summer-run and fall-run races. In the summer-run race, one population is known to use a specific type of spawning grounds. The fall-run race includes three populations with different types of spawning grounds. These four populations correspond to four eco-geographical groups separated reproductively by geographical

Abstract The characteristics of the farming of hatchery-reared juvenile Yesso scallop, Mizuhopecten yessoensis, in suspended net cages off the eastern coast of Primorsky Krai are studied. The work was conducted at a farm located northeast of Moryak-Rybolov Bay during the first 10 days of November 2018. The values of survival and growth rates of scallops on collectors and grow-out cages were determined

Abstract Chum salmon (Oncorhynchus keta) is an endangered species in China. The numbers of chum salmon have declined sharply in the wild, especially the population entering into the Tumen River (Jilin Province) which is the boundary river between China and North Korea. In order to solve the conflict between China and North Korea about the ownership of the population, we developed ten novel microsatellite

Abstract Reverse transcription quantitative PCR (RT-qPCR) is commonly used for gene expression analysis. Appropriate reference genes enable the accurate quantification of gene expression. In this study, expressional stability of seven candidate reference genes in embryos and larvae of the Echiura Urechis unicinctus were evaluated using four programs, geNorm, NormFinder, BestKeeper, and ∆Ct method.

Abstract The genetic differences between the sockeye salmon populations of the Kamchatka Peninsula were studied. The time of divergence between the resident sockeye salmon, which are reproductively isolated in Lake Kronotskoye, and the anadromous sockeye salmon is estimated using data on microsatellite markers. A weak unidirectional gene flow is observed from resident sockeye salmon into the population

Abstract This study determined the range of conditionally normal values of the catalase activity (СA) in the Black Sea red macroalga Ceramium virgatum. The level of CА in the alga corresponded to its conditionally normal functioning (26.79 ± 10.32 μg H2O2/(g wet weight min)). The minimum concentrations of hydrochemical parameters that correspond to the sensitivity threshold of CА in C. virgatum were

Abstract The abundance and community structure of nirS-encoding and nirK-encoding denitrifiers inhabiting the sediment of the Pearl River Estuary was examined with quantitative PCR and high-throughput MiSeq sequencing. The results indicated that the low-oxygen condition (around 4 mg/L) of the Pearl River Estuary was the suitable environment for the denitrifying bacterial growth, and the abundances

Abstract— The sequenced genome data from the sea urchin Strongylocentrotus purpuratus were used to identify transposons (TEs, transposable elements) and test for the presence of some of them in the genome of the sea urchin S. intermedius. The known TEs of S. purpuratus from the RepBase repeats database were used to calculate the primers and identify the corresponding TEs in the S. intermedius transcriptome