The effect of environmental conditions on distribution,growth and life span of <Emphasis Type="Italic">Protothaca euglypta</Emphasis> (Mollusca: Bivalvia)

The distribution and growth of the bivalve mollusk Protothaca euglypta in Peter the Great Bay and at the northern boundary of its area were investigated. It is shown that in some biotopes P. euglypta biomass reaches 1–2 kg/m², which exceeds the estimated values of abundance obtained for most associated species of mollusks. It has been established that local variability of P. euglypta growth rates can be compared with latitudinal variability, and the life span increases from the southern part of the area towards its northern boundary. It has been concluded that P. euglypta occupies a more prominent position in the malacofauna of shallow waters in its abundance, than it was considered earlier.     

Morphofunctional characterization of the reproductive system of the gastropods <Emphasis Type="Italic">Littorina brevicula,L. mandshurica</Emphasis>, and <Emphasis Type="Italic">Nucella heyseana</Emphasis> from uncontaminated and contaminated areas of Peter the Great Bay,Sea of Japan

The structure and state of the reproductive system were studied in the periwinkles Littorina brevicula and L. mandshurica from the coastal area of Vladivostok and in the dogwhelk Nucella heyseana from the protected area of Vostok Bay and from contaminated sites in Amursky Bay. These species were investigated for the presence of imposex and intersex (pathological changes caused by endocrine disruption under the influence of toxic substances). The pathological changes revealed in the gonads of Littorina were oocyte resorption and lipofuscin accumulation; an intersex condition was not found. Imposex specimens (with penis formation) were found among Nucella females from Amursky Bay. The relative penis length in females was 25% of the penis length in males. This kind of pathology was not found in Nucella from clean waters of Vostok Bay.     

Responses of <Emphasis Type="Italic">Venerupis philippinarum</Emphasis> (Mollusca: Bivalvia) to Predators and Changes in Hydrodynamics

The rate of burrowing into sand by the bivalve mollusk Venerupis philippinarum was studied under laboratory conditions. It is found that an increase in the intensity of water flow to an average of 1000 ml/min stimulates the burrowing of the mollusk, while higher values suppress burrowing; the threshold values are somewhat different for the young and adult specimens. It is shown that the presence of the starfish Asterias amurensis in the experimental environment decreases the rate of burrowing of V. philippinarum by 10–20% depending upon the sizes of the predator and the potential victim, but the depth of penetration of the mollusks into the sediment increases. It is supposed that in V. philippinarum and other species of bivalve mollusks related to the same life form and characterized by a moderate capability to burrow into the ground, the adaptive strategy of threat avoiding (great wave activity, an approach of a predator) is expressed as burrowing into a depth uncommon for usual situations and waiting. This behavior, to a significant degree, provides the capability of some species to inhabit shallow water areas with poor hydrodynamics inhabited by numerous predators.     

Delineating species for conservation using mitochondrial sequence data: the taxonomic status of two problematic <Emphasis Type="Italic">Bombus</Emphasis> species (Hymenoptera: Apidae)

Across Western Europe and North America, many bumblebee species are currently undergoing drastic declines in their abundance and ranges, primarily as a result of habitat fragmentation. In contrast, a smaller number of species are seemingly unaffected by this and remain common. The UK Biodiversity Action Plan-designated Bombus ruderatus belongs to the former group while B. hortorum belongs to the latter. These two species are sympatric and remarkably similar in morphology. There are no diagnostic characters for workers and male genitalia are illustrated with the same diagram in standard keys. Isolated records of putative B. ruderatus occur amongst a mass of records for B. hortorum. This raises two important issues: first, are B. ruderatus and B. hortorum ‘good’ species? Second, if they are, can the uncertainty over their identification be resolved? We present COII and cytochrome b mtDNA sequence data from these and other Bombus species. Molecular data and coat colour characters are in concordance and confirm that B. ruderatus and B. hortorum should be regarded as separate species (although coat colour alone is an unreliable diagnostic character for many individuals). Confirmation of the specific status of B. ruderatus allows the work on the conservation of this species to continue.     

Large numbers of marine mammals winter in the North Water polynya

The importance of the North Water polynya in Smith Sound as an overwintering area for marine mammals has been questioned. One way to address the issue is to assess the abundance of selected marine mammals that are present during winter in the North Water. Visual aerial surveys involving double observer platforms were conducted over the eastern part of the North Water polynya in April 2014. Four species of marine mammals were included in strip-census estimation of abundance. Perception bias was addressed using a double-platform survey protocol, a Chapman mark–recapture estimator for whales, seals and walruses (Odobenus rosmarus) on ice and a mark–recapture distance sampling estimation technique for walruses in water. Availability bias was addressed by correcting abundance estimates by the percentage of time animals detected in water that were available for detection at the surface. The resulting estimates suggested that 2544 walruses (95 % CI 1513–4279), 6005 bearded seals (Erignathus barbatus, 95 % CI 4070–8858), 2324 belugas (Delphinapterus leucas, 95 % CI 968–5575) and 3059 narwhals (Monodon monoceros, 95 % CI 1760–5316) wintered in the eastern part of the North Water polynya in April 2014. The walrus estimate is larger than previous summer estimates, and it emphasizes the importance of the habitat along the Greenland coast as a walrus wintering ground. The estimate of belugas is likely negatively biased due to the partial coverage of the potential habitat. The estimate of narwhals is large compared to the few previous observations of narwhals in winter in the North Water, and it demonstrates that large numbers of narwhals winter there. The overall conclusion is that the North Water is indeed an important wintering area for at least walruses, belugas, narwhals and bearded seals.     

Trojan Horse Strategy for Non-invasive Interference of <Emphasis Type="Italic">Clock</Emphasis> Gene in the Oyster <Emphasis Type="Italic">Crassostrea gigas</Emphasis>

RNA interference is a powerful method to inhibit specific gene expression. Recently, silencing target genes by feeding has been successfully carried out in nematodes, insects, and small aquatic organisms. A non-invasive feeding-based RNA interference is reported here for the first time in a mollusk bivalve, the pacific oyster Crassostrea gigas. In this Trojan horse strategy, the unicellular alga Heterocapsa triquetra is the food supply used as a vector to feed oysters with Escherichia coli strain HT115 engineered to express the double-stranded RNA targeting gene. To test the efficacy of the method, the Clock gene, a central gene of the circadian clock, was targeted for knockout. Results demonstrated specific and systemic efficiency of the Trojan horse strategy in reducing Clock mRNA abundance. Consequences of Clock disruption were observed in Clock-related genes (Bmal, Tim1, Per, Cry1, Cry2, Rev.-erb, and Ror) and triploid oysters were more sensitive than diploid to the interference. This non-invasive approach shows an involvement of the circadian clock in oyster bioaccumulation of toxins produced by the harmful alga Alexandrium minutum.     

Demographics and spatial ecology in a population of cryptic wood white butterfly <Emphasis Type="Italic">Leptidea juvernica</Emphasis> in Northern Ireland

The cryptic wood white Leptidea juvernica is one of a newly-discovered species complex comprising three morphologically similar species in Europe. In the British Isles, L. juvernica is absent from Great Britain, but is widespread in Ireland, where it has experienced recent declines; it is classed as a priority species in Northern Ireland. Using a mark–recapture approach, this study aims to elucidate the population and spatial ecology of L. juvernica based on a population resident on a small, suburban site and to propose conservation measures. The results demonstrated that populations of L. juvernica, even on small sites, can reach high numbers during the peak flight season. Unusually for European Pieridae, there was only weak evidence of protandry in this population, possibly reflecting weather conditions prior to the flight season. The spatial distribution and abundance of L. juvernica was associated with the distribution of its larval host-plants, as well as maintaining close proximity to south-facing habitat edges for shelter. Males had a closer association to sheltered habitat edges, whilst females were found more commonly on open ground with a shorter sward which was the preferred egg-laying habitat. Long vegetation in sheltered areas was important for roosting during periods of non-activity. These results inform conservation measures which will benefit L. juvernica; appropriate measures focus on habitat management providing a mosaic of open, semi-natural grassland interspersed with tall vegetation, scrub, and trees.     

Interactions of Algae within the Community of <Emphasis Type="Italic">Gracilaria gracilis</Emphasis> (Rhodophyta)

Interactions among the unattached red alga Gracilaria gracilis, the dominant species of an algal community, and associated algal species Chaetomorpha linum, Enteromorpha prolifera f. prolifera, and Polysiphonia sp. were studied during and after an algal bloom. It was shown that during their bloom the associated algae Enteromorpha and Polysiphonia sp. significantly decreased the photosynthetic rate of G. gracilis but did not affect its growth rate. It is suggested that the inhibition of Gracilaria gracilis photosynthesis is connected to the impact of extracellular metabolites excreted by Chaetomorpha linum, Enteromorpha prolifera f. prolifera, and Polysiphonia sp. In laboratory experiments, the photosynthetic rate of the associated species was enhanced in the presence of Gracilaria. However, no significant alterations were observed in the content of chlorophyll a, growth, and the dark respiration rates of associated algae when they were kept together with Gracilaria. It was suggested that allelopathic interactions observed among algal species during the formation of the monospecific Gracilaria community, as well as during algal blooms, are not determinative.     

Effect of excretory-secretory products of some fouling organisms on settling and metamorphosis of the larvae of <Emphasis Type="Italic">Styela rustica</Emphasis> (Ascidiae)

The effect of the excretory-secretory products of some fouling animals on the settling and metamorphosis of larvae of the solitary ascidian Styela rustica was assessed. The substances secreted by the sponge Halichondria panicea stimulated settling of larvae, but concurrently blocked their metamorphosis. The excretory-secretory products of the mussel Mytilus edulis and the ascidian Molgula citrine did not affect settling of the S. rustica larvae but impeded their subsequent development. Water conditioned by the bivalve Hiatella arctica, stimulated settling and, apparently, metamorphosis of the larvae of S. rustica. The chemical substances produced by adult individuals of S. rustica facilitated settling of conspecific larvae but slightly delayed their metamorphosis.     

Effect of the excretory-secretory products of some marine invertebrates on byssus production of the blue mussel <Emphasis Type="Italic">Mytilus edulis</Emphasis> (Bivalvia: Mytilidae)

Under laboratory conditions, we investigated byssus production in the blue mussel Mytilus edulis, as affected by the excretory-secretory products (ESPs) of the mussel itself and some marine invertebrates: the predatory starfish Asterias rubens, and organisms competing with mussels in White Sea fouling communities—a bivalve Hiatella arctica, the solitary ascidians Styela rustica and Molgula citrine, and a sponge Halichondria panicea. The number of attachment disks produced by a mussel per day and the thickness of byssal threads were estimated. Excretory-secretory products of H. arctica and M. citrine had no effect on the number of attachment disks, while ESPs of S. rustica, H. panacea and A. rubens stimulated mussels to produce attachment plaques. The activity of the mussel was slightly increased at low levels of its own ESPs in seawater. The thickness of byssal threads decreased with an increase in the ESPs of mussels in seawater, but it increased in experiments with the ESPs of any other species tested.     

Population responses by <Emphasis Type="Italic">Orius insidiosus</Emphasis> to vegetational diversity

The abundance of different life stages of Orius insidiosus (Say) (Heteroptera: Anthocoridae) and its prey were recorded in vegetationally diverse (soybean and agronomic weeds) and monoculture (soybean only) fields. Orius insidiosus adults and nymphs were more abundant in diversified plots than in monocultures. A similar number of O. insidiosus eggs were found in the two treatments, but twice as many eggs were laid on non-crop plants than on soybeans within the vegetationally diverse plots. Prey densities were equivalent in the two treatments. In olfactometer assays, naïve O. insidiosus females were unresponsive to odors from three weed species (morning glory, redroot pigweed and velvetleaf). The current results, coupled with previous experimental observations, lead us to believe that higher abundance of O. insidiosus in vegetationally diverse habitats could be related to improved fitness of the predator, which in turn is related to certain plant qualities (e.g., nutrition, plant architecture, etc.). Proximal cues are likely more influential to oviposition decisions by O. insidiosus females than volatile signals.     

Regulatory activity of heterologous gene-activator <Emphasis Type="Italic">xlnR</Emphasis> of <Emphasis Type="Italic">Aspergillus niger</Emphasis> in <Emphasis Type="Italic">Penicillium canescens</Emphasis>

The gene encoding the xlnR xylanolytic activator of the heterologous fungus Aspergillus niger was incorporated into the Penicillium canescens genome. Integration of the xlnR gene resulted in the increase in a number of activities, i.e. endoxylanase, β-xylosidase, α-L-arabinofuranosidase, α-galactosidase, and feruloyl esterase, compared to the host P. canescens PCA 10 strain, while β-galactosidase, β-glucosidase, endoglucanase, and CMCase activities remained constant. Two different expression constructs were developed. The first consisted of the nucleotide sequence containing the mature P. canescens phytase gene under control of the axhA promoter region gene encoding A. niger (1,4)-β-D-arabinoxylan-arabinofuranohydrolase. The second construct combined the P. canescens phytase gene and the bgaS promoter region encoding homologous β-galactosidase. Both expression cassettes were transformed into P. canescens host strain containing xlnR. Phytase synthesis was observed only for strains with the bgaS promoter on arabinose-containing culture media. In conclusion, the bgaS and axhA promoters were regulated by different inducers and activators in the P. canescens strain containing a structural tandem of the axhA promoter and the gene of the xlnR xylanolytic activator.     

Distribution and habitats of <Emphasis Type="Italic">Phengaris</Emphasis> (<Emphasis Type="Italic">Maculinea</Emphasis>) butterflies and population ecology of <Emphasis Type="Italic">Phengaris</Emphasis><Emphasis Type="Italic">teleius</Emphasis> in China

Many species of the butterfly genus Phengaris are regarded as endangered in many parts of their distribution. Several species are also widely distributed across northern China. Due to land use change and overgrazing, their habitats are declining and many patches have been lost. This paper investigates the distribution and habitats of the Chinese Phengaris species (of the subgenus Maculinea). Shrub-grassland near forests seem the most frequent habitat for Phengaris, while flat open grasslands are mostly over-grazed and thus survival for Phengaris butterflies there seems difficult. Throughout Europe, P. teleius is an endangered species, while there is still no information on its status in China. To improve the knowledge on the population ecology of P. teleius, its population structure, adult behaviour and movement were studied through mark–release–recapture methods in the Qinling Mountains of Taibai County. Eight grassland patches which were potentially suitable were found in the area in 2013. In total, 480 individuals (274 females) were marked, resulting in an overall recapture rate of 16 %. The average daily population size was 44 butterflies (±23 SD) during the adult flight period. Sixty-seven percent of the females and 38 % of the males moved less than 50 m, and 17 % of recaptured females and 38 % of males moved more than 200 m. The mean movement distance was 107 ± 177 m for males and 182 ± 122 m for females. The majority of the recaptures (86 %) were made within the patches, only a few individuals (14 %) moved between patches. Due to human disturbance and destruction, all of the eight potentially suitable patches are becoming smaller and increasingly isolated, thus these populations of P. teleius may face an increasing risk of extinction, which may well be a tip of the iceberg of habitat loss and fragmentation of P. teleius in Taibai County and possibly beyond. Hence we hope our initial study of P. teleius could have positive impacts on the conservation of Phengaris butterflies in China.     

The Concentrations of Trace Metals in the Soft Tissues of the Mytilid Mollusk <Emphasis Type="Italic">Septifer bilocularis</Emphasis> (Linnaeus, 1758) as a Possible Indicator of Water Quality at Coastal Coral Reefs of Vietnam

The variability of Fe, Mn, Zn, Cu, Pb, Cd, and Ni concentrations was studied in soft tissues of the common mytilid mollusk Septifer bilocularis collected in May 2013 at the coral reefs along the entire Vietnamese coast from the Gulf of Siam to Ha Long Bay. The salinity, suspended solids, and nutrients were determined during the sampling; these hydrochemical characteristics of the surrounding waters were controlled by the river runoff and the content of chlorophyll a. The concentration of Mn in the mollusk S. bilocularis was elevated under the river runoff effect. However, concentrations of Cd and Zn in S. bilocularis were the lowest within the areas of river influence and increased in waters of central Vietnam and the Gulf of Siam, where upwellings are an important driving force. A comparison of our data with those obtained for Mytilidae from other regions showed that the mussel S. bilocularis can be recommended for biomonitoring of the concentrations of trace metals in the waters of coral ecosystems along the Vietnam coast.     

Molecular genetic characterization of the yeast <Emphasis Type="Italic">Lachancea kluyveri</Emphasis>

A comparative study of Lachancea kluyveri strains isolated in Europe, North America, Japan, and the Russian Far East was performed using restriction analysis, sequencing of non-coding rDNA regions, molecular karyotyping, and the phylogenetic analysis of the α-galactosidase MEL genes. This study showed a close genetic relatedness of these L. kluyveri strains. The chromosomal DNAs of the L. kluyveri strains were found to range in size from 980 to 3100 kb. The haploid number of chromosomes is equal to eight. The IGS2 restriction patterns and single nucleotide substitutions in the ITS1/ITS2 rDNA region correlate neither with geographic origin nor with the source of the strains. The L. kluyveri strains isolated from different sources have a high degree of homology (79–100%) of their MEL genes. The phylogenetic analysis of all of the known α-galactosidases in the “Saccharomyces” clade showed that the MEL genes of the yeasts L. kluyveri, L. cidri, Saccharomyces cerevisiae, S. paradoxus, S. bayanus, and S. mikatae are species specific.     

The influence of upwelling,coastal currents and water temperature on the distribution of the red tide dinoflagellate, <Emphasis Type="Italic">Noctiluca scintillans</Emphasis>, along the east coast of Australia

Quasi-synoptic surveys along the east coast of Australia between 28 and 34°S show that the heterotrophic dinoflagellate, Noctiluca scintillans, occurs along this entire stretch of the coast. Areas of relatively high abundance of Noctiluca were observed downstream of regions predisposed to current-induced upwellings as a consequence of alongshore topographic variations. High-resolution temporal and spatial sampling of upwelling events showed that Noctiluca was abundant (up to 28 cells l^?1) within mature upwelled waters. A high proportion (>80%) of fed Noctiluca cells (cells with prey in their vacuoles) was observed in the mature upwelled waters indicating that the observed increase in abundance of Noctiluca was associated with increased feeding activity. The absolute abundance of Noctiluca in upwelled waters was, however, found to vary from one upwelling location to another and between seasons. In particular, highest abundances of Noctiluca were recorded south of 31.5°S, where the East Australian Current (EAC) characteristically separates from the coast. The high abundances partly arise from southward advection and retention of the Noctiluca cells, and partly from upwelling inshore of the separated EAC driven by cross-shelf boundary layer fluxes. The temperature of the EAC was also found to influence absolute abundances. Surface water temperatures during our summer cruise were anomalously high due to a strong La Niña phase, and up to 4°C warmer than during our spring cruise. We found that the warmer surface water temperatures were associated with relatively lower average abundances of Noctiluca in the near shore zone.     

On the multicomponent nature of <Emphasis Type="Italic">Halobacterium salinarum</Emphasis> flagella

Filaments of the flagellum of the halophilic archaeon Halobacterium salinarum consist of five flagellins: A1, A2, B1, B2, and B3, which are encoded by five genes localized in tandem in two flgA and flgB operons. While the role of flagellins A1 and A2 has been determined, the role of the proteins, B operon products, is still unclear. A mutant strain of H. salinarum with deleted A and B flagellin genes (ΔflgAΔflgB) has been obtained for the first time. This strain has been used to create and analyze the strains carrying only individual B1 or B3 flagellin genes. Cells of the ΔflgAΔflgB strain were shown to have short filamentous formations, 7–8 nm thick, which we have named as X-filaments. It has been shown that X-filaments consist of a protein immunologically related to flagellins A and B. Expression of the B1 and B3 genes is suppressed in the absence of A1, A2, and B2. It has been shown that flagellins B1 and B3 cannot be substituted for flagellin B2 upon the formation of a curved hook-like structure, which serves as a connecting element between the flagellar filament and the motor axis. The multicomponent nature of flagella is discussed in the light of their possible involvement in other cell processes besides providing motility.     

High level of tetracosapolyenoic fatty acids in the cold-water mollusk <Emphasis Type="Italic">Tochuina</Emphasis><Emphasis Type="Italic">tetraquetra</Emphasis> is a result of the nudibranch feeding on soft corals

Fatty acid (FA) markers are used to trace predator–prey relationships in the marine environment. Soft corals contain tetracosapolyenoic acids (TPA), namely 24:5n-6 and 24:6n-3, which are considered as octocoral FA markers. The nudibranch mollusks are known to feed on soft corals. To check whether TPA are transferred from soft corals to nudibranch mollusks during their nutrition, we determined and compared FA compositions of total lipids of Tochuina tetraquetra and soft corals (Acanella sp., Anthomastus rylovi, Gersemia fruticosa, and Paragorgia arborea) collected together near the Kuril Islands (the depths of 80–550 m). FA compositions of T. tetraquetra, Acanella sp. and A. rylovi were described for the first time. In Acanella sp., G. fruticosa, A. rylovi, and P. arborea, the average contents of TPA were 6.5, 13.4, 5.9, and 12.0 % of total FAs, whereas the 24:5n-6/24:6n-3 ratio was 1.0, 1.4, 5.4, and 2.6, respectively. The high level of TPA (21.7 %) found in T. tetraquetra indicates that 24:5n-6 and 24:6n-3 are transferred from soft corals to the mollusks during their feeding and accumulated in mollusk tissues. The most possible feed source of the mollusk is suggested to be G. fruticosa and/or Acanella sp., because the 24:5n-6/24:6n-3 ratios in T. tetraquetra and these soft corals were similar. Thus, the TPA could be used as FA markers to estimate a proportion of soft corals in feeding of cold-water nudibranch mollusks.