A Model-Based Study of Phytoplankton Condition Using Remote Sensing Data for the Western Kamchatka Shelf

Russian Journal of Marine Biology - A method for estimating the integral microalgae biomass beneath a unit surface was designed based on a mathematical model for phytoplankton vital function in the...     

Feeding Patterns in Different Size Larvae of Walleye Pollack, Theragra chalcogramma (Pallas, 1814) on the Shelf of Western Kamchatka

The stomach contents were examined in 373 walleye pollack larvae of different sizes. The diet of pollack larvae included more than 20 plankters of different sizes. Phytoplankton was the major food source of 4- to 6-mm-long larvae. The proportion of phytoplankton in the larval diet decreased as the larvae grew, and the late larval stages shifted entirely to a diet of zooplankton. As the larvae increased in size, the spectrum of food organisms changed from smaller to larger sizes. In the larvae 4 to 31 mm long, the length of prey varied from 0.1 (Coscinodiscus) to 6.0 mm (Neocalanus plumchrus). The average daily repleteness of pollack larvae varied from 32 to 210. The minimum repleteness was registered in 4- to 6-mm-long larvae with mixed feeding (endogenous and exogenous); in 30- to 35-mm-long fish the repleteness was the greatest. The daily food rations calculated for the most abundant size groups of larvae ranged from 4.3 to 6.6% of their body weight.     

Current Trends in the Condition of Bottom Fish Communities from the West Kamchatka Shelf

Based on the data of two summer surveys carried out in 2002, the biomass of bottom fishes of the West Kamchata Shelf was assessed. The obtained results were considered within the series of similar annual assessments conducted since 1996. It was displayed that against the background of some increase in the total biomass of bottom fishes, the biomass of the plaices prevailing there, which had previously been the two dominating species had decreased. As a result of the quantitative variations that occurred, the present community structure differs considerably from that observed over the past twenty years.     

Initial Stage of Macrozoobenthos Formation in Reservoirs of Western Mongolia

Data on the initial stage of macrozoobenthos formation in the Taishir and Durgun reservoirs in western Mongolia in 2010–2015 have been generalized. A taxonomic list of macrozoobenthos is presented; 15 species have been recorded in Mongolia for the first time. In the Durgun Reservoir, the formation of bottom sediments and communities of invertebrates in the near-dam part is accelerated due to the water-flow transport of reed beds and invertebrates from Lake Khar-Us. The macrozoobenthos in the Taishir Reservoir is formed first due to consumers of terrigenous organic matter (decaying terrestrial vegetation and soils), and then by inhabitants of sapropelic mud; complexes of filter feeders, Spongilla lacustris (L.), are formed in the profundal zone. The process of macrozoobenthos development in the reservoir is similar to that in lowland reservoirs. After the construction of the reservoir, quantitative characteristics of macrozoobenthos increased downstream of the dam in the Dzabhan River and rheophilic species were replaced by limnophilic ones.     

甲壳动物精子学研究概况Ⅱ. 精子发生与精子的生化组成

在前文阐述了甲壳动物精子形态和结构的基础上,本文着重概述其精子发生与精子的生化组成.     

The Current Status of the Red King Crab (Paralithodes camtschaticus) Stock and Fishery off Western Kamchatka

Russian Journal of Marine Biology - The current status of the red king crab population off western Kamchatka is considered based on data from bottom trawl surveys and fishery statistics since 2013....     

Distribution,Size and Sex Composition of Gymnocanthus pistilliger (Cottidae) off the Western Coast of Kamchatka in the Summer Period and Modern State of its Resources

Journal of Ichthyology - In the summer period of 2017, the threaded sculpin Gymnocanthus pistilliger occurred at depths from 14 (minimum depth of trawling) to 64 m in the Sea of Okhotsk off the...     

Macrozoobenthos of the Small Aral Sea

Benthic assemblages of the Small Aral Sea were studied in 1999. The species composition, density, and biomass of benthic invertebrates were determined. The vertical distribution pattern and its dynamics in the course of desiccation of the sea were analyzed. It is shown that the vertical distribution of the benthos has changed substantially over the last 30 years. The biomass of the benthos in the inshore zone increased, while in the central part of the sea, benthic invertebrate populations declined and gradually disappeared. These changes are likely to be due to the accumulation of organic matter in the bottom sediments and the weakening of hydrodynamic processes, which could lead to oxygen depletion in deep water. In the 1990s, the benthic assemblages of the Small Aral Sea were relatively stable and highly productive. It is concluded that the Aral Sea is a promising area for fishery restoration.     

Temperature Affects Stoichiometry and Biochemical Composition of Escherichia coli

Temperature is a master variable controlling biochemical processes in organisms, and its effects are manifested on many organizational levels in organisms and ecosystems. We examined the effects of temperature on the biochemical composition and stoichiometry of a model heterotrophic bacterium, Escherichia coli K-12, held at constant growth rate in chemostats. Increasing temperature led to increased cellular organic carbon (C) and organic nitrogen (N) with decreased phosphorus (P) content, leading to increased C/P and N/P biomass ratios. P content was related to cellular RNA, which is P-rich (9–10% by weight) and nonnucleic acid P (presumably composed of mostly phospholipids, intracellular phosphate, and polyphosphate). These results indicate that E. coli allocates an increased proportion of its P cell quota toward assembly (ribosomes) at low temperatures and an increasing proportion toward resource acquisition machinery (membranes) at higher temperatures. If these results are relevant to the behavior of prokaryotic heterotrophs in natural settings (the gut, soils, lakes, oceans, etc.), it suggests greater nutrient regeneration and less microbial nutrient retention as temperatures increase.     

The Biophysical Properties of Basal Lamina Gels Depend on the Biochemical Composition of the Gel

The migration of cells within a three-dimensional extracellular matrix (ECM) depends sensitively on the biochemical and biophysical properties of the matrix. An example for a biological ECM is given by reconstituted basal lamina gels purified from the Engelbreth-Holm-Swarm sarcoma of mice. Here, we compare four different commercial variants of this ECM, which have all been purified according to the same protocol. Nevertheless, in those gels, we detect strong differences in the migration behavior of leukocyte cells as well as in the Brownian motion of nanoparticles. We show that these differences correlate with the mechanical properties and the microarchitecture of the gels which in turn arise from small variations in their biochemical composition.     

Polysaccharides of Algae: 55. Polysaccharide Composition of Several Brown Algae from Kamchatka

A new spectrophotometric procedure was developed for the quantitative determination of fucoidan and alginic acid and used for their analysis in extracts from biomass of 17 species of brown algae collected from coastal waters of the Kamchatka peninsula. In addition, neutral monosaccharides and mannitol were determined in the hydrolysis products of the alga biomass samples. The polysaccharide composition was shown to substantially depend on the algal species. The alginic acid content was maximal in the Alaria marginatablades; all the other representatives of the order Laminariales also are useful sources of this polysaccharide. At the same time, the fucoidan content is rather low in Laminariales. The highest content of fucoidan was found in Saundersella simplex, but Chordaria flagelliformisand Fucus evanescensare more practical fucoidan sources; the available supplies and the sugar composition make the latter alga the most suitable for the complex processing to prepare mannitol, fucoidan, and alginic acid.     

Macrozoobenthos assemblages in springs of the Penza region

Classification of spring macrozoobenthos assemblages was carried out using original data. Five types of assemblages were identified: Potamophylax nigricornis-Baetis rhodani-Cnetha spp.-Nemouridae, Rhyacophila fasciata; Stenophylax lateralis-Euglesidae-Ptychoptera spp.; Asellus aquaticus; Apatania auricular. The differentiation factors of these assemblages are water flow, water velocity, which are independent conditions, and substrate type. Comparison of classification with other variants of classification of spring macrozoobenthos found in the literature was carried out.     

The Distribution of Macrozoobenthos Taxa,as Potential Indicators of Vulnerable Marine Ecosystems in the Western Bering Sea: 1. Anadyr Bay Area

The composition of common species in some macrozoobenthos groups that are considered as potential indicators of vulnerable marine ecosystems (VME), in the Anadyr Bay area, Bering Sea have been determined based on the results of four benthic surveys using a benthic grab sampler (1985, 2005) and a bottom trawl (2008, 2012). These are soft corals (Gersemia rubiformis), sponges (Myxilla incrustans, Halichondria panicea, and Semisuberites cribrosa), ascidians (Halocynthia aurantium and Boltenia ovifera), bryozoans (Cystisella saccata and Flustra foliacea), barnacles (Chirona evermanni), and the brittle star (Gorgonocephalus eucnemis). The distribution of these animals has been mapped. Aggregations of immobile sestonophages (the former five groups) are formed on hard coarse-grained and mixed sediments in waters with higher hydrodynamic activity (along the southwestern and northeastern coasts of the Anadyr Bay, mainly at depths of 80–90 m). In some cases, sponges and bryozoans in the southern part of the area can descend to a depth of 250 m (in the Navarin Canyon). The mobile filterer G. eucnemis forms aggregations mainly on soft sediments in the central part of Anadyr Bay, at depths of 50–270 m, in the area of a localized spot of near-bottom cold water. According to the results of trawl surveys conducted in 2008 and 2012, the mean biomass of the sponges, the brittle star G. eucnemis, and the sea squirt B. ovifera did not change, whereas the mean biomass of the barnacle Ch. evermanni and sea peach H. aurantium decreased by 6.5 and 3.7 times, respectively. Since the level of trawl fishing activity in the region is not high, the hypothesis has been proposed that the decrease in the abundance of the latter two species is presumably caused by the natural dynamics of their population or can be related to the factor of randomness, as these species are caught in their mosaically distributed local aggregations.     

An Analysis of Microsatellite Polymorphism in the Population of the Arctic Rainbow Smelt Osmerus dentex from Eastern and Western Kamchatka

Russian Journal of Genetics - The genetic diversity of ten microsatellite loci is examined in samples of Arctic rainbow smelt. The expected heterozygosity estimates vary in the range of...     

抗白粉病小麦染色体组型的分子标记与生化标记分析

应用与小麦第六同源群有关的分子和生化标记,包括ＤＮＡ探针ｐＳｃ５·３Ｈ３和ｐＳＲ１６７以及同工酶Ｅｓｔ－５和ａ－Ａｍｙ－１,对来自六倍体小黑麦Ｂｅａｇｌｅ与普通小麦科冬５８杂交后代Ｆ１花粉植株的抗白粉病株系Ｍ２４．Ｍ０９及Ｍ１７进行了分析。结果表明,Ｍ２４、Ｍ０９及Ｍ１７不同程度地含有黑麦染色体成分,而且电泳谱带差别较大,据此推断,Ｍ０９为６ＲＬ的易位系。因此,生化和分子标记不仅可以用于确定外源片段的存在,而且可以帮助确定染色体组型和外源片段的位置     

Prochloron (Prochlorophyta): Biochemical Contributions to the Chlorophyll and RNA Composition

The prochlorophyte Prochloron, a symbiont of the colonial ascidianDidemnum molle, was collected in the Indian Ocean around Giravaru(Maldives) in depths between 1 and 40 m. The chlorophyll a tob ratio of the algal symbionts was higher in colonies livingbetween 1–6 m, compared to that determined for Prochloronfrom a depth of 30 m. This property for chromatic adaptationin correlation with changes in the total content of chlorophyllis dependent upon environmental factors. The association betweenDidemnum and Prochloron is only a facultative symbiosis. Thesize of the colonies, growing near the water surface is large(up to 3 cm), and it gradually decreases to 0.2 cm in a depthof 30 m dim locations. At a depth of 40 m the tunicates do notcontain the algal symbionts. Applying quantitative preparative isolation and sensitive immunologicalas well as biochemical detection techniques we have no evidencefor the existence of poly(A) stretches in RNA species from Prochloron.Moreover, we failed to detect both sn/scRNAs and their proteins,typically associated with them in RNP complexes from eukaryotes.From the data we suggest that mRNA synthesis proceeds in Prochloronin a way similar to prokaryotes. ¹ This contribution is dedicated to Prof. Dr. Dr. B. Schmidton the occasion of his 50th birthday.