Russian Journal of Marine Biology最新文献

Abstract

The strategies to protect the vulnerable Zhanjiang Mangrove Reserve from polychlorinated biphenyls (PCBs) pollution have attracted great attention. PCBs are hard to degrade in the ecosystem and easy to accumulate in sediments. PCBs can be enriched into animals and humans through the food chain, causing “three toxicities”, thus endangering the health of the body. In this study, the PCBs-degrading bacteria in the mangrove sediments of Gaoqiao, Zhanjiang were filtered. 16S rRNA was amplified from the genomes of these bacteria, and the products were purified and sequenced for isolation and identification of the bacteria. A total of 20 strains of PCBs-degrading bacteria were isolated from sediment samples of the low, middle and high tide zones of the Zhanjiang Mangrove Reserve, among which Bacillus and Pandoraea showed the best degradability with a higher level of PCB degradation rates of 92.2 and 97.8%, respectively. These results were helpful for future research, including genetic screening, cloning and restructuring, and instructive for the cultivation of PCBs-degrading bacteria.

Abstract

The allelic diversity of the DQB gene of the major histocompatibility complex (MHC) in the Atlantic walrus from the European part of the Arctic was analyzed for the first time. We studied animals from the haulouts located on the Franz Josef Land archipelago and near the northern tip of Novaya Zemlya. We demonstrated that there are significant differences for this locus between the two studied haulouts. Simultaneous analysis of microsatellite loci reveals a lower level of differentiation and also suggested that animals from more than one spatial-geographical stock (population) gather at the summer haulout on Novaya Zemlya. It has been suggested that individuals with different MHC genotypes may prefer different feeding areas, regardless of the areas of residence during the breeding season.

An Erratum to this paper has been published: https://doi.org/10.1134/S1063074023320019

Abstract

Five specimens of encysted trematode metacercariae of Pygidiopsis Looss, 1907, located outside the tissues of the host, in a free state, were found in the extrapaleal cavity of the gastropod mollusc Hydrobia acuta (Draparnaud, 1805) from Cossack Bay (Black Sea). A figure, an image, and measurements of excisted larvae were given.

Abstract

This article is one of a series of publications concerning new and little-known macroalgae of Peter the Great Bay, Sea of Japan. Our study was carried out from February, 2021 to July, 2022. A total of eight species are described, of which six are new species for this aquatic region. Three species are also newly reported for the flora of the Far Eastern seas of Russia; two species were previously noted in the bay, but not described. We provided detailed descriptions and illustrations for all of these species.

Abstract

This paper presents the recent data on the distribution and breeding abundance and distribution of the Mongolian Gull, Slaty-backed Gull, Black-tailed Gull and the Common Tern nesting within Peter the Great Bay of the Sea of Japan. Over the past 30 years, all species of gulls increased their abundance, while the Common Tern has almost ceased to nest on the islands of the bay.

Abstract

The results of a study of the cultivated yesso scallop Mizuhopecten yessoensis (Jay, 1857) in Primorsky Krai in 2014–2021 are presented. The death of molluscs in mariculture farms was noted, the symptoms of the “dermo” disease were studied: high mortality of scallops that have reached 2 years of age, observed during autumn displacement into new cages in September, the presence of protozoa of the genus Perkinsus Levine, 1978 in the tissues of organs, foci of damage of the adductor muscle, nonclosure of the shell valves, black discoloration, necrotizing of soft tissues. The minimum level of the parasitic load was established as 10–15 parasitic hypnospores per mollusc. However, considering the danger of a disease that causes mass death of molluscs for several years, the rapid spread of the pathogen, and significant economic losses, it is recommended to create a specialized laboratory in the region for diagnosing and constantly monitoring the state of mariculture farms.

Abstract

The content of a dangerous amnesic toxin, that is, domoic acid (DA), was determined in cultures of the diatom genus Pseudo-nitzschia and in bivalve samples collected in the Russian waters of the Sea of Japan and off the Pacific coast of Kamchatka. For the first time, the presence of DA has been confirmed in cultures of Pseudo-nitzschia pungens (Grunow ex Cleve) G.R. Hasle, 1993 and P. delicatissima (Cleve) Heiden, 1928 from the Pacific coast of Kamchatka with the use of the competitive enzyme-linked immuno-sorbent assay (cELISA). Relatively high concentrations of DA were recorded in the horse mussel Modiolus kurilensis F.R. Bernard, 1983 (2.92 mg/kg based on high-performance chromatography-mass spectrometry (HPLC-MS) and 2.8 mg/kg based on cELISA) and in the Gray mussel Crenomytilus grayanus (0.07 mg/kg based on HPLC-MS and 0.2 mg/kg based on cELISA) collected in the Sea of Japan. It has been shown that for assessing relatively low concentrations of amnesiotoxin (less than 5 ng/mL in microalgal cultures and less than 0.05 mg/kg in mollusks) the cELISA assay is an alternative to HPLC, which does not allow one to detect DA in such samples.

Abstract

Samples of macrophyte algae were collected from an ecotope of Kandalaksha Gulf, the White Sea. These algae were selected from substrates, storm wracks and after long-term storage in the soil, and they were assessed by indirect competitive enzyme immunoassay for the presence of low-molecular-weight metabolites of micromycetes (mycotoxins). In Fucus distichus, F. serratus, F. vesiculosus, and Ascophyllum nodosum, the concentrations of all analyzed toxic substances from storm wracks were uniformly reduced compared to those in living thalli. For Laminaria digitata, Saccharina latissima, and Ahnfeltia plicata, in living individuals of which mycotoxins were not found or were extremely rare, cases of contamination with citrinin, mycophenolic acid, emodin and sterigmatocystin were found in storm wracks. After 12 months of burial in soil F. distichus samples had only 9 components out of 16 analyzed. In F. serratus, F. vesiculosus, A. nodosum, and Pelvetia canaliculata, only emodin, mycophenolic acid, alternariol, and ergot alkaloids were determined.

Abstract

The biological features of Atlantic cod in the coastal zones of the Murman for 1999–2006 were studied. The age composition, growth rate and maturation, feeding habits, and structure of otoliths were analyzed. Histological and genetic studies were carried out. It has been shown that young cod mainly lives and spawns in Western Murman bays. Older cod leaves the bays due to insufficient food supply. The growth rate of young coastal cod is comparable to that of cod in the open part of the Barents Sea. With age, the cod of the open sea areas noticeably overtakes the cod that lives in the coastal zone in growth. It was noted that the cod spawns in the bays with both coastal and Atlantic types of otoliths. Studies of genetic polymorphisms indicate a high degree of genetic similarity between cod groups in the Norwegian and Barents Seas under the influence of currents (branches of the Norwegian Atlantic Current, the Murmansk Coastal Current) and against the background of migrations at different stages of ontogeny of cod from coastal and open water areas.