Japanese Scallop Mizuhopecten Yessoensis Research Articles

Experiment on growing of japanese scallop <i>Mizuhopecten yessoensis</i> in cages in the Aniva Bay

Results of experimental growing of japanese scallop Mizuhopecten yessoensis in the first three years of life in cages mounted in the Aniva Bay (southern Okhotsk Sea) are presented. Mean size and weight of the mollusks are determined and their growth rate and survival are compared with these indices for juvenile scallops from natural settlements in the Aniva Bay and other habitats located in the Far East region. Feasibility of the cage method for commercial cultivation of the scallop in conditions of the Aniva Bay is concluded.

Hemolytic compound 3,7,11,15-tetramethyl-hexadecan-1,19-disulfate found in the invasive European sea squirt Ascidiella aspersa

The solitary European sea squirt Ascidiella aspersa was introduced to northern Japan, causing dense coverage of the aquacultured Japanese scallop Mizuhopecten yessoensis. There are concerns that allelopathy by the sea squirt will suppress the growth of the scallop. Herein, we studied the allelopathic and defensive potential of A. aspersa using hemolytic assay. An alkyl sulfate, viz. 3,7,11,15-tetramethyl-hexadecan-1,19-disulfate (1), was isolated as a hemolytic compound, and 1 showed mild toxicity against the Japanese scallop and brine shrimp.

Verification of authenticity: A rapid identification method for commercial scallop species through multiplex real-time PCR

Seafood products are particularly vulnerable to food fraud and mislabelling, which may have negative implications on fisheries resources, economy, consumer health and trust. This is a considered problem for scallops, since these high-valued seafood products are usually sold without their morphologically characteristic shells. Scallop products differ in taste and value and usually species of the genus Pecten spp. are especially expensive in many European countries. The aim of the present study was the development of a multiplex TaqMan real-time PCR assay that allows a rapid and reliable authentication of the three commercially important species/genera Pecten spp. (usually King scallop P. maximus), Atlantic sea scallop Placopecten magellanicus, and Japanese scallop Mizuhopecten yessoensis. The design of primers and probes was based on mitochondrial 16S rRNA gene amplifying fragments of 138–198 bp. Following the optimization of the multiplex real-time PCR assay, analyses on efficiency, limit of detection, specificity, robustness, and crosstalk were conducted for validation purpose. Average Cq values of 20 ng DNA obtained for Pecten spp. were 17.64 ± 0.89, for P. magellanicus 18.42 ± 0.83, and for M. yessoensis 17.08 ± 0.79. Non-target species produced either no fluorescence signal or the Cq differed significantly from those of target species (p < 0.01). Finally, the newly developed real-time PCR assay was tested on commercial samples from German supermarkets and fishmongers accompanied by simultaneous verification through Sanger sequencing, which revealed a high mislabelling rate of 48%, especially for products purchased at fishmongers. The results emphasize the need of a control method that allows the rapid analysis of sufficient sample quantities. The study is one of the first which presents a multiplex TaqMan real-time PCR approach for the authentication of commercially important seafood species.

Prospects for using the Busse Lagoon as a natural source for producing the spat of japanese scallop Mizuhopecten yessoensis

Reproduction of japanese scallop Mizuhopecten yessoensis in the Busse Lagoon (Sakhalin Island) is investigated. Abiotic environments influence on duration of early stages in its life cycle is determined. Interannual variability of the scallop larvae abundance and timing of its settling on substrata is traced. The Busse Lagoon is recommended for using as a natural source of seeding material (spat) of japanese scallop.

Characteristics of valve movement pattern of the Japanese scallop Mizuhopecten yessoensis related to environmental changes

Characteristics of valve movement pattern of the Japanese scallop Mizuhopecten yessoensis related to environmental changes

The antioxidant system of the Gray’s mussel Crenomytilus grayanus (Dunker, 1853) and the Japanese scallop Mizuhopecten yessoensis (Jay, 1857) (Mollusca: Bivalvia)

This study examines the parameters of the antioxidant system (the activities of antioxidant enzymes: superoxide dismutase, catalase, glutathione peroxidase, glutathione reductase, as well as the levels of reduced glutathione and integral antioxidant activity) in the digestive gland, gills, gonads, and adductor muscles of two bivalve species: the mussel Crenomytilus grayanus (Dunker, 1853), which lives attached to the substrate, and the Japanese scallop Mizuhopecten yessoensis (Jay, 1857), which is capable of free movement. Species- and tissue-specific differences of the antioxidant system of the investigated mollusks are discussed in connection with their physiological and biochemical peculiarities.

Molecular Cloning, Characterization, and Expression of a Catalase Gene in the Japanese Scallop Mizuhopecten yessoensis Induced in the Presence of Cadmium

Cadmium (Cd) is known to influence the oxidative status of marine organisms and can induce the formation of reactive oxygen species (ROS). Catalase (CAT) is one of the important enzymes involved in scavenging high levels of ROS. In present study, we cloned CAT cDNA and investigated the response of this enzyme at the transcriptional level in the Japanese scallop Mizuhopecten yessoensis exposed to Cd. The full-length CAT cDNA (MyCAT) of 1,870 nucleotides including a 57 bp 5’-UTR, a coding sequence of 1,500 bp and a 313 bp 3’-UTR were identified from the scallop. The deduced amino acid sequence of MyCAT corresponds to 499 amino acids with predicted molecular weight of 56.48 kDa and contains highly conserved motifs of the proximal heme-binding site RLFSYSTH, proximal active signature FNRERIPERVVHAKGGG and three catalytic amino acid residues His72, Asn145, and Tyr355. Its significant homology to CATs from multiple alignments revealed that MyCAT had a high identity with CATs from other mollusks. CAT mRNA expression analysis revealed that expression level was highest in the digestive gland (p < 0.01) but weak in muscle. Following exposure to 200 and 400 µg/l of Cd, a high amount of Cd was found to have accumulated in the digestive gland and CAT mRNA expression had significantly increased in this organ among 7-day exposed scallops (p < 0.001). The result demonstrated that antioxidant enzymes such as CAT play important roles in counteracting Cd stress in M. yessoensis.

Nitrogen stable isotopes reveal age-dependent dietary shift in the Japanese scallop Mizuhopecten yessoensis

ABSTRACTOntogenetic niche shifts in diet are a consequence of changes in body size or resource partitioning between age classes. To better resolve the feeding patterns of the Japanese scallop Mizuhopecten yessoensis, we examined the relative importance of age and size in the diet of this species using stable isotope ratios of carbon (δ13C) and nitrogen (δ15N) from 2006 to 2009. Contribution of food sources was quantified using an isotope mixing model by comparing the muscle tissue isotope ratios to those of suspended particulate organic matter (SPOM) and their zooplankton prey (e.g. micro- and meso-zooplankton). Unlike the δ13C values, which remained constant with age and size, muscle δ15N values were more positively correlated with age accounting for 69 % of variations than size with only 46 %. Increasing 15N values with age suggested that shifts in diet from SPOM to micro- and meso-zooplankton occurred during ontogeny in M. yessoensis. Results of the isotope mixing model indicated that SPOM contribution to scallop’s diet decreased from 68 to 8 % while those of zooplankton increased from 15 to 50 % with increasing age. This study concludes that age-related dietary shift explains the enrichment of 15N, as a result of predation on zooplankton by M. yessoensis.

The distribution of macrobenthic epifauna in the Far Eastern Marine Reserve based on remote underwater video data

The spatial distribution of epifauna in the Far Eastern Marine Reserve was examined using a remotely operated vehicle. The abundance and distribution patterns of the sea stars Patiria pectinifera, Distolasterias nipon, and Asterias amurensis, as well as those of brittle stars, the black sea cucumber Cucumaria japonica, the sea urchin Strongylocentrotus intermedius, the ascidian Halocynthia aurantium, hermit crabs, and the Japanese scallop Mizuhopecten yessoensis were determined in the South Section of the Reserve. The average biomass of five dominant epifaunal species ranged from 51.0 to 87.4% of the average biomass of the softbottom communities.

A Comparative Study of Survival, Metabolism, Immune Indicators, and Proteomics, in Five Batches of Japanese Scallop Mizuhopecten yessoensis under Short-Term High Temperature Stress

Five batches of the Japanese scallop Mizuhopecten pyessoensis were tested for survival rate, oxygen consumption, catalase (CAT) and superoxide dismutase (SOD) activities, total antioxidant capacities (T-AOC) contents, and proteomics under short-term high temperature conditions. The five batches, (W1, W2, W3, W4, W5) selected from the established 21 ‘ivory white’ M. yessoensis batches, had higher survival rates than the other batches after one year of culture. Initial rearing water temperature of 15°C was increased by 1°C per day with a cooling and heating system. The temperature was raised until over 50% of the scallops from 3 batches died. This occurred at 30°C. The higher than normal culture temperature conditions showed significant or highly significant differences in the responses of some of the batches. Some showed significantly higher survival rates and significantly different rates of oxygen consumption. CAT activity, SOD activity and T-AOC content was similar in the five batches, and all three indices were significantly lower in W3 and W5 than in the other batches (P&lt;0.01). Expression patterns of MDA content were opposite to those of CAT activity, SOD activity and T-AOC content. Protein profiles of all five batches were similar; the sizes of the predominant bands ranged from 20-110 kDa. We identified twenty-eight proteins with high scores in the database. These included heat shock proteins (HSPs), glucose-regulated protein 94, and arginine kinase.

Purification and characterization of metal-binding proteins from the digestive gland of the Japanese scallop Mizuhopecten yessoensis

Marine bivalves accumulate high concentrations of potentially toxic heavy metals in their tissues. We report here our investigation of the accumulation patterns of cadmium (Cd), copper (Cu), and lead (Pb) in tissues of the Japanese scallop Mizuhopecten yessoensis after exposure to artificial seawater containing Cd, Cu, or Pb. Our results revealed that accumulation of these heavy metals by this scallop was associated with certain intracellular metal-binding proteins (MBPs). Cd was accumulated at higher concentrations than Cu and Pb, and most of the accumulated metals were detected in the digestive gland. MBPs from the digestive gland were purified and subjected to a preliminary characterization. Three proteins with molecular masses of approximately 28, 37, and 42 kDa, respectively, were isolated by gel-filtration and anion-exchange column chromatography. Characterization of the partial amino acid sequences of these proteins show high sequence similarity to MBPs and ion-transporters. Metalloprotein profiles in the digestive gland indicated that some proteins were upregulated after metal exposure, suggesting that these proteins are involved in mechanisms of metal accumulation and detoxification in M. yessoensis.

A C-type lectin fold gene from Japanese scallop Mizuhopecten yessoensis, involved with immunity and metamorphosis.

C-type lectins are a superfamily of Ca(2+)-dependent carbohydrate-recognition proteins that are well known for their participation in pathogen recognition and clearance. In this study, a putative C-type lectin fold (MyCLF) gene was identified from the Japanese scallop Mizuhopecten yessoensis. The full-length of MyCLF was 645 bp, encoding a polypeptide of 167 amino acids. MyCLF carried a signal peptide of 20 amino acid residues, and a single carbohydrate recognition domain, having relatively high amino acid sequence conservation with C-type lectins reported for other bivalves. The expression of MyCLF mRNA transcripts in adult tissues, after bacterial challenge and during different developmental stages was determined using real-time quantitative RT-PCR. MyCLF was mainly distributed in the mantle, gill, and kidney. The expression of MyCLF clearly increased 3 h after Vibrio anguillarum challenge, and dropped to a minimum level after 9 h compared to the control group. During embryonic development, the expression level increased in the gastrulae, trochophore and early D-shaped larvae, decreased in D-shaped larvae, and then increased hundreds of times in metamorphosing larvae. The results suggested that MyCLF was involved in an immune response and it may play important roles during the metamorphosis phase of M. yessoensis.

Comparison of fungal complexes of Japanese scallop Mizuhopecten yessoensis (Jay, 1856) from different areas in the Peter the Great Bay of the Sea of Japan

Mycological investigation of the Japanese scallop Mizuhopecten yessoensis (Jay) (Bivalvia) from different areas of the Peter the Great Bay (Sea of Japan) was conducted. Isolates from internal organs of M. yessoensis scallop comprise 72 species of filamentous fungi from 30 genera of ascomycetes, anamorphic fungi, and zygomycetes. Species richness of filamentous fungi—fungi of the genera Aspergillus, Penicillium, Cladosporium, and Chaetomium—in the internal organs of bivalve mollusks increases in polluted coastal waters.

Study of enhancement and inhibition phenomena and genes relating to degradation of petroleum polycyclic aromatic hydrocarbons in isolated bacteria

Mycological investigation of the Japanese scallop Mizuhopecten yessoensis (Jay) (Bivalvia) collected in different areas of the Peter the Great Bay, Sea of Japan, was carried out. A total of 72 species of filamentous fungi belonging to 30 genera of ascomycetes, anamorphous fungi, and zygomycetes was isolated from the internal organs of the scallop. The species.diversity of mycelial fungi in the internal organs, especially of members of the generaAspergillus, Penicillium, Cladosporium, and Chaetomium, was found to increase in polluted coastal waters.

The regional impacts of climate change on coastal environments and the aquaculture of Japanese scallops in northeast Asia: case studies from Dalian, China, and Funka Bay, Japan

Climate changes affect coastal environments and aquaculture, threatening food security and economic growth. Japanese scallop (Mizuhopecten yessoensis) culture is economically important for the coastal communities of Dalian, China, and Funka Bay, Japan. In this study, we combined satellite remote-sensing data, in situ observations, and a suitable aquaculture site selection model to explore the interactions between marine environments and climate variability over a recent 10-year period (2003–2012). Our selection of appropriate zones in these two Far Eastern regions and our analyses of climatic event (Arctic Oscillation (AO), winter East Asian monsoon (EAM), and El Niño/La Niña Southern Oscillation (ENSO)) and meteorological (precipitation, temperature, and wind) data allowed us to determine the impacts of climate change on regional coastal environments and prospects for scallop aquaculture. These analyses showed that AO and EAM strongly influenced the aquaculture areas on the Dalian coast through their effects on temperature during winter. We also determined that wind was the main driving force behind regional environmental changes during spring. Conversely, ocean conditions and suitable areas in Funka Bay changed rapidly relative to oceanic and atmospheric circulation. In Funka Bay, areas appropriate for scallop aquaculture and variations in chlorophyll-a concentration (which reflect the availability of algal food for scallops) were strongly correlated with ENSO, precipitation, and air temperature. These correlations demonstrate the influence of oceanic and atmospheric parameters on the productivity of scallop aquaculture in Funka Bay. Adaptation to oceanic and atmospheric changes should be considered when developing plans and management strategies for coastal scallop aquaculture in northeast Asia.

Effect of high temperature on survival, oxygen consumption, behavior, ammonia-N excretion, and related immune indicators of the Japanese scallop Mizuhopecten yessoensis

In this study, two experiments were conducted to test the effect of high temperature on survival, behavior, oxygen consumption, ammonia-N excretion, and enzyme activities related to oxidative stress of the Japanese scallop Mizuhopecten yessoensis. In the first test, we abruptly transferred scallops from the rearing temperature (15 °C, control temperature) to 20, 22, 24, and 26 °C. Scallops exposed to 26 °C were significantly affected by temperature, with 100 % mortality after 12 h. The 8-, 12-, 24-, 48-, and 96-h lethal temperatures for 50 % mortality (LT50) were 27.5, 24.4, 24.3, 24.2, and 23.8 °C, respectively. The activities of CAT and SOD and the T-AOC in the coelomic fluid of M. yessoensis changed significantly after high-temperature stress (P < 0.05). They reached to the highest levels after 8 h of stress in the 22, 24, and 26 °C treatment groups then returned to the control group level. The content of MDA reached the highest level after 12 h in each temperature treatment. In the second test, scallops were acclimatized to the different temperature levels (20, 22, 24, and 26 °C) and then maintained for 30 days. Survival was significantly lower at 26 °C than at the other temperatures, and the highest survival occurred in the 15 °C treatment. High temperature also significantly influenced the oxygen consumption rates and ammonia-N excretion rates (P < 0.05). As the temperature increased, the CAT and SOD activities and the T-AOC in the coelomic fluid of M. yessoensis declined significantly, whereas the MDA content increased. These results illustrate that high temperature can significantly affect the survival, behavior, oxygen consumption, ammonia-N excretion, and enzyme activities related to oxidative stress of M. yessoensis.

Predation Impact of Small Drilling Gastropods on the Japanese ScallopMizuhopecten yessoensis

ABSTRACT Although the Japanese scallop Mizuhopecten yessoensis is the variety used in the largest production of scallops in the world, knowledge about its predators is very limited, and gastropods have not generally been recognized as a predator. This study demonstrates the impact of predatory gastropods on the Japanese scallop through a field survey and laboratory experiments. The 4-y field survey at a lagoon in northern Japan demonstrated that the frequency of scallops that have boreholes on their shells represented 11.3%–73.8% of dead individuals at 3 y old (shell height, >90 mm) that would have been harvested 7 mo later. By calculating the natural mortality of scallops after their release on the sowing—culture grounds in the lagoon, we estimated that 17.8% of the released scallops were attacked by drilling animals. This estimation, however, probably underestimates the impact of drilling predators, because the drilling frequency on small (young) individuals (shell height, <55 mm) was 10 times greater t...

Identification and expression analysis of cDNA encoding chitinase-like protein (CLP) gene in Japanese scallop Mizuhopecten yessoensis.

Chitinase-like proteins (CLP) are important members of the glycoside hydrolase family 18 (GH18) and are involved in growth control and remodeling processes. In this study, a CLP transcript was isolated and sequenced from the Japanese scallop (Mizuhopecten yessoensis) after screening expressed sequence tags. The full-length complementary DNA of M. yessoensis CLP (My-Clp1) was 1555 bp in length, consisting of a 75-bp 5'-untranslated region (UTR), a 160-bp 3'-UTR, and a 1320-bp open reading frame bearing characteristics of the GH18 family. The My-Clp1 protein was well conserved, with similar domain structures and architecture across species (e.g., from mollusks to mammals). Expression analysis in healthy tissues and across developmental stages revealed a strong preference for expression; My-Clp1 was abundantly expressed in the mantle and throughout metamorphosis, which suggests the involvement of My-Clp1 in the synthesis of extracellular components, and tissue degeneration and remodeling. My-Clp1 expression was induced after infection with a bacterial pathogen, Vibrio anguillarum, suggesting its involvement in immunity against this intracellular pathogen.

Element profile and chemical environment of sulfur in a giant clam shell: Insights from μ-XRF and X-ray absorption near-edge structure

We used micro X-ray fluorescence (μ-XRF) to investigate element profiles of sulfur in the inner layer of an aragonitic clam shell (Hippopus hippopus), and we used sulfur K-edge X-ray absorption near-edge structure (XANES) to evaluate the local environment of sulfur in aragonitic (H. hippopus, freshwater pearl mussel Hyriopsis sp.) and calcitic (Japanese scallop Mizuhopecten yessoensis) bivalve shells. The spectra of S K-edge XANES collected from bivalve shells and S-bearing organic and inorganic reference materials indicated that inorganic sulfate was present in marine aragonitic and calcitic bivalve shells. However, XANES results did not permit us to discriminate between organic and inorganic sulfate in freshwater aragonitic shells. The first-order fluctuations of sulfur in the inner shell layer showed clear annual fluctuations, with sulfur concentrations being lower during periods of faster growth. Our results suggest that trace sulfur profiles in aragonitic shells could be the result of cyclic changes of shell growth related to insolation or some influencing factors of shell growth.

De Novo Characterization of Japanese Scallop Mizuhopecten yessoensis Transcriptome and Analysis of Its Gene Expression following Cadmium Exposure

BackgroundJapanese scallop has been cultured on a large-scale in China for many years. However, serious marine pollution in recent years has resulted in considerable loss to this industry. Moreover, due to the lack of genomic resources, limited research has been carried out on this species. To facilitate the understanding at molecular level immune and stress response mechanism, an extensive transcriptomic profiling and digital gene expression (DGE) database of Japanese scallop upon cadmium exposure was carried out using the Illumina sequencing platform.ResultsRNA-seq produced about 112 million sequencing reads from the tissues of adult Japanese scallops. These reads were assembled into 194,839 non-redundant sequences with open reading frame (ORF), of which 14,240 putative amino acid sequences were assigned biological function annotation and were annotated with gene ontology and eukaryotic orthologous group terms. In addition, we identified 720 genes involved in response to stimulus and 302 genes involved in immune-response pathways. Furthermore, we investigated the transcriptomic changes in the gill and digestive gland of Japanese scallops following cadmium exposure using a tag-based DGE system. A total of 7,556 and 3,002 differentially expressed genes were detected, respectively, and functionally annotated with KEGG pathway annotations.ConclusionThis study provides a comprehensive transcripts sequence resource for the Japanese scallop and presents a survey of gene expression in response to heavy metal exposure in a non-model marine invertebrate via the Illumina sequencing platform. These results may contribute to the in-depth elucidation of the molecular mechanisms involved in bivalve responses to marine pollutants.