Structure of aggregations and principal populational characteristics of redfish <Emphasis Type="Italic">Sebastes mentella</Emphasis> (Scorpaeniformes: Scorpaenidae) in the pelagic zone of the Irminger Sea and adjacent waters

The spatial distribution of redfish Sebastes mentella in the pelagic zone of the northern part of the Atlantic Ocean (the Irminger Sea and the Labrador Sea) is investigated. Analysis of the data on size-age composition, sex ratio, ratio of mature and immature specimens, rate of maturation, composition of the parasite fauna, infestation level, infestation with the copepod Sphyrion lumpi, and occurrence of pigment formations on the body of redfish from the investigated areas indicate the absence of stable isolated aggregations of this species in the oceanic pelagial of the North Atlantic. Pelagic aggregations are formed of rapidly maturating specimens migrated from the slopes of Greenland. The spatial variation of the size-age composition of redfish depends on the life cycle and regional hydrological conditions.     

Allozyme variability in populations of trout (<Emphasis Type="Italic">Salmo trutta</Emphasis>) from the rivers of Iran

For the first time, an analysis was carried out of allozyme variability in trout (Salmo trutta) from three rivers of Iran. We studied 23 gene loci coding enzymes: glycerol-3-phosphate dehydrogenase (G3PDH), aspartate aminotransferase (AAT), malate dehydrogenase (MDH), lactate dehydrogenase (LDH), creatine kinase (CK), malic enzyme [NADP-dependent MDH] (MEP), superoxide dismutase (SOD), esterase (EST), and esterase D (EST-D). The obtained data demonstrate the similarity between the trout samples from different rivers of Iran according to genetic characteristics. Taking into account the differences by allozyme markers of allele frequencies and allele composition of some loci, we should expect that Iranian trout diverges significantly in genetics from the other trout populations of the Caspian Sea.     

Mitochondrial DNA polymorphism of atlantic cod of the Barents and White seas

High level of intraspecific polymorphism of the mtDNA cytochrome b gene in the Atlantic cod Gadus morhua L. from the northeastern part of the species range (Barents and White seas) is detected. The absence of genetic differentiation between the samples from different areas of the Norwegian and Barents seas is shown, and the fact that these samples belong to the same population of Northeast Arctic cod is confirmed. Significant differences in the frequences of mitochondrial DNA haplotypes between the cod from the Barents and White seas, as well as from the northwestern part of the range, are found. The cod Gadus morhua kildinensis Derjugin, 1920 from Mogilnoye Lake and Gadus morhua marisalbi Derjugin, 1920 from the White Sea were revealed to have common haplotypes with the cod from the Barents Sea, confirming the recent origin of these forms from the Atlantic cod G. morhua.     

Intraspecies structure of beaked redfish <Emphasis Type="Italic">Sebastes mentella</Emphasis> of the Atlantic and Arctic oceans

On the basis of the results of complex interdisciplinary investigations of the population composition and structure of the beaked redfish Sebastes mentella of the Atlantic and Arctic oceans, its three populations are discerned relatively isolated from each other by the system of permanent marine currents—North Atlantic, Flemish-Cape, and Norway-Barents Sea. The population structure of the species in the southern part of its area corresponds to the model of a local stock. Interaction of the North Atlantic and the Norway-Barents Sea populations well correspond to the model of fluctuating stocks. Redfish aggregations in different biotopes (mesobenthal and mesopelagial) are intrapopulational epigenetic groups. In the period of warm and anomalously warm years, a part of mature specimens from the pelagial of the North Irminger Sea make an irreversible migration to the southern part of the Norwegian Sea and form there mixed aggregations of fish from the North Atlantic and Norway-Barents Sea populations. With consideration of the effect of climatic–oceanological processes, a principally new scheme is elaborated describing the process of seasonal migrations of redfish in the mesobenthal and mesopelagial. The previous views on direction of return migrations of redfish of the Norway-Barents Sea population are reconsidered. Juveniles from the western part of the Barents Sea and Spitsbergen not only supplement the demersal aggregations but also migrate to the pelagial of the Norwegian Sea.     

Microsatellite Variability of Pacific Herring <Emphasis Type="Italic">Clupea pallasii</Emphasis> Valenciennes, 1847 from the Sea of Okhotsk and Bering Sea

The genetic variability of ten microsatellite loci was examined in samples of the herring from the Sea of Okhotsk and the Bering Sea. All loci were polymorphic; the expected heterozygosity estimates varied in the range of 0.3–94.3% (mean 66.7%). The degree of genetic differentiation of the herring was statistically significant (θ = 1.38%). The level of pairwise genetic differentiation F_ST was–0.002–0.046; R_ST was–0.003–0.166. Genetic differentiation of the herring from the Sea of Okhotsk and the Bering Sea correlated with the spatial-geographic structure of the species in the studied range on the basis of F_ST (P = 0.001).     

The distribution and specific features of the biology of deepwater redfish <Emphasis Type="Italic">Sebastes mentella</Emphasis> (Scorpaenidae) during mating in the pelagial of the northern Atlantic

Data on the spatial-bathymetric distribution, size and age composition, sex ratio, and feeding of deepwater redfish Sebastes mentella in the pelagial of the northern Atlantic (Irminger and Labrador seas) during mating are provided. From 1982 to 1999, the mating of S. mentella took place in the central and southern parts of the Irminger Sea (56°–62° N, 30°–43° W); since 2000 it took place in two geographically isolated areas: in the water area of the open part of the Labrador Sea, at sites of the south of the Irminger Sea adjacent to it (54°–58° N, 38°–50° W), and above the western slopes of the Reykjanes Ridge (62°–65° N, 25°–34° W). It is assumed that during mating in the northern area mixed aggregations of two ecological groups of S. mentella—an oceanic group that distributes in the pelagial and a bottom group that inhabits the slopes of Iceland—are formed. The formation of isolated areas of mating of the species is determined by the orientation of feeding migrations that are simultaneously migrations to spawning grounds. Fish of medium sizes migrate to spawning grounds in the southwestern direction, while large fish migrate in the northern direction; the fertilization of females in these areas occurs at the end of summer. In S. mentella, the seasonal and age differences in food composition are clearly pronounced. With the onset of mating, the males’ intensity of feeding in both regions decreases by a factor of 1.5–2.0, while females continue to feed actively.     

A new species of the conodont genus <Emphasis Type="Italic">Polygnathus</Emphasis> from the Tournaisian of the northern Urals,Chernyshev Ridge and Pai-Khoi

A new conodont species, Polygnathus postvogesi sp. nov., from the Tournaisian deepwater deposits of the northern Urals, southeastern part of the Chernyshev Ridge, and central Pai-Khoi is described. The new species continue the phylogenetic lineage of the Late Devonian polygnathid P. marginvolutus Gedik, P. vogesi Ziegler.     

First record of blurred smooth lanternshark, <Emphasis Type="Italic">Etmopterus bigelowi</Emphasis> from Indonesia

The blurred smooth lanternshark, Etmopterus bigelowi Shirai and Tachikawa, 1993 was recorded for the first time from Indonesian waters based on two specimens collected from a deepwater shark fishery operated in the Flores Sea, eastern Indonesia. This is also the second confirmed record of Etmopterus species from this country.     

Identification of a New 1,4-beta-D-xylosidase <Emphasis Type="Italic">Pae</Emphasis>1263 from the Whole Genome Sequence of <Emphasis Type="Italic">Paenibacillus terrae</Emphasis> HPL-003

The gene of Pae1263 (2,196 bp, 732 aa) was found from the full-length sequence analysis of bacterium Paenibacillus terrae HPL-003 isolated from soil on Gara Mountain in Korea (CP003107, our previous study). Among the 20 open reading frames (ORFs) related with the xylose substrate, only the recombinant enzyme of ORF Pae1263 showed a 1,4-beta-D-xylosidase activity when all of the ORFs were transformed into E. coli. This gene is considered to be a new 1,4-beta-D-xylosidase because it has up to 93% similarity with other genes of ZP_10240221.1 from Lactococcus raffinolactis 4877 and ZP_11237858.1 from Paenibacillus peoriae in the GenBank blast search. The enzyme activity was confirmed by HPLC in which xylose was produced from xylobiose as a substrate by this recombinant enzyme. Mass production of the recombinant enzyme was done with the construction of the pET22(+)- Pae1263-6H expression vector system from E. coli. This new 1,4-beta-D-xylosidase was highly active at 50°C in a pH range between 6.0 and 8.0 and had thermo-stability for at least 24 h at 50°C and a K _m and V _max of 6.42 mg/mL and 75.76 U/mg on a xylobiose substrate, respectively.     

Preliminary data on the variability of three microsatellite loci in Pacific <Emphasis Type="Italic">Gadus macrocephalus</Emphasis> and Atlantic <Emphasis Type="Italic">G. morhua</Emphasis> cod (Gadidae)

Variability of microsatellite DNA loci Gmo3, Gmo34, and Gmo35 is studied in samples of Pacific cod Gadus macrocephalus and Atlantic cod G. morhua. The results show high values of identity of the samples within the North Pacific basin (0.9766–0.9924) and within the Northeast Atlantic basin (0.9580). Based on the pairwise assessment of genetic differentiation, the F _ST values are significantly different in all variants between the samples of Pacific and Atlantic cod (F _ST = 0.5235–0.6719, p < 0.001). Within the basins, the significant differences in the frequencies of main alleles are revealed in the loci Gmo3 and Gmo34 for the samples from the Pacific and Atlantic oceans, respectively.     

The Spatial Variability of the Fluorescent Characteristics of Phytoplankton in the Black Sea

The spatial variability of the photochemical efficiency of phytoplankton photosystem II was analyzed in two contrasting regions of the Black Sea: the western part of the deepwater region and a region influenced by the Danube River discharge. The fluorescence values for open (F₀) and closed (F_m) photosystem II reaction centers in the investigated areas varied by an order of magnitude and correlated closely. The potential photochemical efficiency of phytoplankton photosystem II (F_m ? F₀)/F_m varied from 0.16 to 0.70. Three types of the vertical distribution of this index were found. In the first type, the values increased from the surface to the top of the thermocline and then remained stable down to the bottom of the euphotic zone; in the second type, they increased from the surface to the bottom of the euphotic zone; in shallow areas, they were stable within the euphotic zone. With an increase in light intensity, the phytoplankton photochemical efficiency decreased. The light inhibition of the photosystem II efficiency was more intense in the deeper than in the upper layers of the euphotic zone.     

The ecological and parasitological characteristics of the golden redfish, <Emphasis Type="Italic">Sebastes norvegicus</Emphasis> (Ascanius, 1772) (Teleostei: Scorpaenidae) that inhabit the Arctic Ocean Seas

An ecological, faunistic, and zoogeographical analysis of the parasite fauna of the golden redfish Sebastes norvegicus (Ascanius, 1772) that inhabit the Barents, Norwegian, and Greenland seas, has been performed. The specifics of formation of the parasite fauna in this species have been studied.     

New Occurrences of Flying Fishes <Emphasis Type="Italic">Cheilopogon melanurus</Emphasis> and <Emphasis Type="Italic">C. heterurus</Emphasis> (Exocoetidae) in the North Central Atlantic and Eastern Part of the Mediterranean Sea

Cheilopogon melanurus, found for the first time in the central part of the North Atlantic (26°34′6 N 33°55′2 W), and C. heterurus from the eastern part of the Mediterranean Sea (Mahmutlar, Alanya, Turkey) are described. C. heterurus is widely distributed in the eastern part of the Mediterranean Sea occurring here in all seasons.     

Population structure and variability of Pacific herring (<Emphasis Type="Italic">Clupea pallasii</Emphasis>) in the White Sea,Barents and Kara Seas revealed by microsatellite DNA analyses

Pacific herring, Clupea pallasii, have recently colonised the northeast Atlantic and Arctic Oceans in the early Holocene. In a relatively short evolutionary time, the herring formed a community with a complex population structure. Previous genetic studies based on morphological, allozyme and mitochondrial DNA data have supported the existence of two herring subspecies from the White Sea and eastern Barents and Kara Seas (C. p. marisalbi and C. p. suworowi, respectively). However, the population structure of the White Sea herring has long been debated and remains controversial. The analyses of morphological and allozyme data have previously identified local spawning groups of herring in the White Sea, whereas mtDNA markers have not revealed any differentiation. We conducted one of the first studies of microsatellite variation for the purpose of investigating the genetic structure and relationship of Pacific herring among ten localities in the White Sea, the Barents Sea and the Kara Sea. Using classical genetic variance-based methods (hierarchical AMOVA, overall and pairwise F _ST comparisons), as well as the Bayesian clustering, we infer considerable genetic diversity and population structure in herring at ten microsatellite loci. Genetic differentiation was the most pronounced between the White Sea (C. p. marisalbi) versus the Barents and Kara seas (Chesha–Pechora herring, C. p. suworowi). While microsatellite variation in all C. pallasii was considerable, genetic diversity was significantly lower in C. p. suworowi, than in C. p. marisalbi. Also, tests of genetic differentiation were indicating significant differentiation within the White Sea herring between sympatric summer- and spring-spawning groups, in comparison with genetic homogeneity of the Chesha–Pechora herring.     

Pelagic larval dispersal habits influence the population genetic structure of clam <Emphasis Type="Italic">Gomphina aequilatera</Emphasis> in China

Pelagic larval dispersal habits influence the population genetic structure of marine mollusk organisms via gene flow. The genetic information of the clam Gomphina aequilatera (short larval stage, 10 days) which is ecologically and economically important in the China coast is unknown. To determine the influence of planktonic larval duration on the genetic structure of G. aequilatera. Mitochondrial markers, cytochrome oxidase subunit i (COI) and 12S ribosomal RNA (12S rRNA), were used to investigate the population structure of wild G. aequilatera specimens from four China Sea coastal locations (Zhoushan, Nanji Island, Zhangpu and Beihai). Partial COI (685 bp) and 12S rRNA (350 bp) sequences were determined. High level and significant F_ST values were obtained among the different localities, based on either COI (F_ST?=?0.100–0.444, P?<?0.05) or 12S rRNA (F_ST?=?0.193–0.742, P?<?0.05), indicating a high degree of genetic differentiation among the populations. The pairwise N_m between Beihai and Zhoushan for COI was 0.626 and the other four pairwise N_m values were >?1, indicating extensive gene flow among them. The 12S rRNA showed the same pattern. AMOVA test results for COI and 12S rRNA indicated major genetic variation within the populations: 77.96% within and 22.04% among the populations for COI, 55.73% within and 44.27% among the populations for 12S rRNA. A median-joining network suggested obvious genetic differentiation between the Zhoushan and Beihai populations. This study revealed the extant population genetic structure of G. aequilatera and showed a strong population structure in a species with a short planktonic larval stage.     

Another look at the interaction between mitochondrial cytochrome <Emphasis Type="Italic">c</Emphasis> and flavocytochrome <Emphasis Type="Italic">b</Emphasis><Subscript>2</Subscript>

Yeast flavocytochrome b ₂ tranfers reducing equivalents from lactate to oxygen via cytochrome c and cytochrome c oxidase. The enzyme catalytic cycle includes FMN reduction by lactate and reoxidation by intramolecular electron transfer to heme b ₂. Each subunit of the soluble tetrameric enzyme consists of an N terminal b ₅-like heme-binding domain and a C terminal flavodehydrogenase. In the crystal structure, FMN and heme are face to face, and appear to be in a suitable orientation and at a suitable distance for exchanging electrons. But in one subunit out of two, the heme domain is disordered and invisible. This raises a central question: is this mobility required for interaction with the physiological acceptor cytochrome c, which only receives electrons from the heme and not from the FMN? The present review summarizes the results of the variety of methods used over the years that shed light on the interactions between the flavin and heme domains and between the enzyme and cytochrome c. The conclusion is that one should consider the interaction between the flavin and heme domains as a transient one, and that the cytochrome c and the flavin domain docking areas on the heme b ₂ domain must overlap at least in part. The heme domain mobility is an essential component of the flavocytochrome b ₂ functioning. In this respect, the enzyme bears similarity to a variety of redox enzyme systems, in particular those in which a cytochrome b ₅-like domain is fused to proteins carrying other redox functions.     

<Emphasis Type="Italic">Paralepidapedon variabile</Emphasis> sp. n. (Trematoda,Lepocreadioidea, Lepidapedidae) and other representatives of the genus <Emphasis Type="Italic">Paralepidapedon</Emphasis> from Antarctic fish

In the Ross Sea and Amundsen Sea, four representatives of the genus Paralepidapedon—Paralepidapedon cf. dubium Prudhoe et Bray 1973 sensu Sokolov et Gordeev 2013, P. lepidum (Gaevskaya et Rodyuk 1988), Paralepidapedon sp., and P. variabile sp. n.—were found in demersal fishes Muraenolepis marmorata and Macrourus whitsoni. Paralepidapedon variabile sp. n. is described from Muraenolepis marmorata in the Amundsen Sea. Paralepidapedon variabile sp. n. differs from other species of the genus Paralepidapedon by the position of the anterior border of the vitellarium at the level of the anterior edge of the ventral sucker or genital pore and by the highly variable shape of the testes: from roundish with a smooth edge to sinuate–lobate. Paralepidapedon lepidum was found for the first time in the Antarctic.     

Construction of flavocytochrome <Emphasis Type="Italic">b</Emphasis><Subscript>2</Subscript>-overproducing strains of the thermotolerant methylotrophic yeast <Emphasis Type="Italic">Hansenula polymorpha</Emphasis> (<Emphasis Type="Italic">Pichia angusta</Emphasis>)

L-Lactate cytochrome c oxidoreductase (flavocytochrome b ₂, FC b ₂) from the thermotolerant methylotrophic yeast Hansenula polymorpha (Pichia angusta) is, unlike the enzyme form baker’s yeast, a thermostable enzyme potentially important for bioanalytical technologies for highly selective assays of L-lactate in biological fluids and foods. This paper describes the construction of flavocytochrome b ₂ producers with over-expression of the H. polymorpha CYB2 gene, encoding FC b ₂. The HpCYB2 gene under the control of the strong H. polymorpha alcohol oxidase promoter in a plasmid for multicopy integration was transformed into the recipient strain H. polymorpha C-105 (grc1 catX), impaired in glucose repression and devoid of catalase activity. A method was developed for preliminary screening of the transformants with increased FC b ₂ activity in permeabilized yeast cells. The optimal cultivation conditions providing for the maximal yield of the target enzyme were found. The constructed strain is a promising FC b ₂ producer characterized by a sixfold increased (to 3 μmol min^?1 mg^?1 protein in cell-free extract) activity of the enzyme.     

Phylogenetic Diversity of the Sulfur Cycle Bacteria in the Bottom Sediments of the Chersonesus Bay

The Black Sea is the largest meromictic basin, in the bottom sediments of which a powerful biogenic process of sulfide production occurs. The goal of the present work was to obtain data on phylogenetic diversity of the sulfur cycle microorganisms (sulfate-reducing and sulfur-oxidizing bacteria) in the Black Sea coastal gas-saturated bottom sediments. The samples were collected in the Chersonesus (Blue) Bay near Sevastopol from whitish bacterial mats of sulfurettes, and from the upper layer of the nearby seabed. Using DNA isolated from the native samples and obtained enrichment cultures, PCR analysis was performed with oligonucleotide primers specific to the fragments of the 16S rRNA genes of the main subgroups of sulfatereducing bacteria (SRB) and to the fragments of the dsrB gene (both reductive and oxidative types), encoding the β-subunit of dissimilatory (bi)sulfite reductase, the key enzyme in the sulfur cycle, inherent in both sulfate- reducing and sulfur-oxidizing microorganisms. The presence of 16S rRNA gene fragments specific to the genera Desulfobacterium, Desulfobacter, Desulfococcus–Desulfonema–Desulfosarcina, and Desulfovibrio–Desulfomicrobium was detected in the DNA samples isolated from coastal bottom bacterial mats. Usage of denaturing gradient gel electrophoresis (DGGE) with subsequent sequencing of reamplified dsrB gene fragments revealed that according to deduced amino acid sequences encoded by the dsrB gene (reductive type), SRB from the coastal gas-saturated bottom sediments of the Black Sea had the highest homology (92?99%) with the dsrB gene of cultured SRB belonging to the genera Desulfovibrio, Desulfatitalea, Desulfobacter, and Desulfobacterium, as well as with uncultured SRB strains from various marine habitats, such as bottom sediments of the Northern and Japanese seas. Deduced amino acid sequences encoded by the oxidative dsrB gene had the highest homology (90?99%) with the relevant sequences of the genera Thiocapsa, Thiobaca, Thioflavicoccus, and Thiorhodococcus.