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Improvement of knowledge of fishing boat operations. -Influences of ship bottom attachment of barnacles and seaweeds
Get PDFOn board research were carried out for investigate the quality of fishing boat under the circumstances, which are observed experimentally in ordinary use on the seas. The present research was prepared in the ordinary operation of maintenances in dock. As the results, it was revealed that fuel consumption was reduced remarkably by cleaning bottom of ship hull, propeller and rudder. And in the condition of foul of ship bottom before cleaning, reducing the rotation speed of the main engine capable of largely improving a fuel efficiency, in comparison to the rate of decrease in ship speed.編集：水産大学校departmental bulletin pape
フリー配偶体培養による温帯性多年生コンブ目褐藻アラメの種苗生産方法
Get PDFIn recent years, the demand for macroalgae seedling production has increased worldwide due to a considerable decline of seaweed beds and increasing anticipation for advantaging “Blue Carbon” as a solution for climate change.
Utilizing free-living gametophyte culture for seedling production for Laminariales kelps (e.g., Saccharina and Undaria) is an efficient and robust technology to address climate change. However, no detailed technical reports of seedling production by free-living gametophyte culture exist today for perennial species, the main component of kelp beds in temperate coastal regions of Japan (e.g., Eisenia bicyclis and Ecklonia cava). In fact, there is a technical bottleneck in their seedling production due to the difficulty in suppressing the maturity of gametophytes to synchronize fertilization. This report describes the method for free-living gametophyte culture of these species by demonstrating a case example of E. bicyclis seedling production, which includes applying Fe-free medium to suppress the maturity of gametophytes.近年，藻場の大幅な減少や気候変動の解決策としてのブルーカーボンへの期待から，大型海藻類の種苗生産の需要が世界的に高まっている。コンブ類やワカメの種苗生産で用いられるフリー配偶体培養は効率的で気候変動に対して頑健な技術である。しかし，我が国温帯域の主要な藻場構成種である多年生褐藻類（アラメ，カジメ等）ではフリー配偶体培養による種苗生産に関する詳細な技術報告はなく，配偶体の受精を同期させるための成熟抑制方法に技術的隘路が存在している。本報告ではアラメ種苗生産の事例を示し，これらの種を対象としたフリー配偶体培養技術，特に鉄成分を含まない培養液による配偶体の成熟抑制方法の適用について記載した。ファイル名末尾に”_abs_j”のファイルは和文要旨journal articl
ホタテガイ中の麻痺性貝毒およびテトロドトキシンを対象とした液体クロマトグラフィータンデム型質量分析法の妥当性評価
No full textホタテガイ中の麻痺性貝毒11成分の妥当性評価試験を実施し，Codexの定める検査法の性能規準を満たしているかを確認した．加えて，近年国内外の二枚貝中よりフグ毒テトロドトキシン（TTX）の含有が報告されていることから，本試験の対象成分とした．Turnerらの方法に従って試験を実施し，溶媒検量線およびマトリックス検量線（ホタテガイ）で定量を行った．妥当性評価の結果は，麻痺性貝毒11成分で目標値（真度，併行精度，室内精度）を満たしたが，TTXを溶媒検量線で定量した場合に低回収率となった．一方で，TTXをマトリックス検量線（ホタテガイ）で定量した場合に，回収率が改善した．以上の結果から，本法はLC-MS/MSを用いた麻痺性貝毒およびTTXの分析について有用な分析法であると考えられるが，適切な検量線の選択が必要であることが示唆された．journal articl
Nocturnal substrate association of four coral reef fish groups (parrotfishes, surgeonfishes, groupers and butterflyfishes) in relation to substrate architectural characteristics
Get PDFAlthough numerous coral reef fish species utilize substrates with high structural complexities as habitats and refuge spaces, quantitative analysis of nocturnal fish substrate associations has not been sufficiently examined yet. The aims of the present study were to clarify the nocturnal substrate associations of 17 coral reef fish species (nine parrotfish, two surgeonfish, two grouper and four butterflyfish) in relation to substrate architectural characteristics. Substrate architectural characteristics were categorized into seven types: (1) eave-like space, (2) large inter-branch space, (3) overhang by protrusion of fine branching structure, (4) overhang by coarse structure, (5) uneven structure without large space or overhang, (6) flat and (7) macroalgae. Overall, fishes were primarily associated with three architectural characteristics (eave-like space, large inter-branch space and overhang by coarse structure). The main providers of these three architectural characteristics were tabular and corymbose Acropora, staghorn Acropora, and rock. Species-specific significant positive associations with particular architectural characteristics were found as follows. For the nine parrotfish species, Chlorurus microrhinos with large inter-branch space and overhang by coarse structure; Ch. spilurus with eave-like space and large inter-branch space; Hipposcarus longiceps with large inter-branch space; Scarus ghobban with overhang by coarse structure; five species (Scarus forsteni, S. niger, S. oviceps, S. rivulatus and S. schlegeli) with eave-like space. For the two surgeonfish species, Naso unicornis with overhang by coarse structure; N. lituratus with eave-like space. For the two grouper species, Plectropomus leopardus with eave-like space; Epinephelus ongus with overhang by coarse structure. For the four butterflyfish species, Chaetodon trifascialis with eave-like space and large inter-branch space; C. lunulatus and C. ephippium with large inter-branch space; C. auriga showed no significant associations with any architectural characteristics. Four species (Ch. microrhinos, H. longiceps, S. niger and N. unicornis) also showed clear variations in substrate associations among the different fish size classes. Since parrotfishes, surgeonfishes and groupers are main fisheries targets in coral reefs, conservation and restoration of coral species that provide eave-like space (tabular and corymbose Acropora) and large inter-branch space (staghorn Acropora) as well as hard substrates with coarse structure that provide overhang (rock) should be considered for effective fisheries management in coral reefs. For butterflyfishes, coral species that provide eave-like space (tabular Acropora) and large inter-branch space (staghorn Acropora) should also be conserved and restored for provision of sleeping sites.journal articl
Literature review on the “neutrophilic” of neutrophilic granules: What is “neutrophilic”?
Get PDFThe term “neutrophilic” and “neutrophilic granule” was first introduced by Paul Ehrlich to identify
specific granules of major polymorphonuclear leukocytes (neutrophils). He used an original staining method, triacid stain, for this purpose. The staining solution, called “neutral mixture”, which was mixture of acidic dye solution and basic dye solution, with soluble form in water (not neutral dye). In this paper, we speculate the structure and characteristics of the dye complex in the neutral mixture. The dye complex has free acidic groups and is expected to behave as an acidic dye. The dye complex bound to the neutrophilic granules stains the granules with the color tone of the dye complex (purple) because the acid and basic dyes do not dissociate. On the other hand, in the vicinity of the eosinophilic granules and nucleus, the dye complex dissociates into acid and basic dyes, and the former bind to the acid dye and the latter to the basic dye. It was inferred that this dye complex is not formed during staining with stains containing neutral dyes, such as May-Grünwald (methylene blue eosinate), Wright (polychromtic methylene blue eosinate), and Giemsa (containing azure II eosinate).編集：水産大学校departmental bulletin pape
石垣島潮間帯域におけるコアマモZostera japonica群落の分布特性と季節的消長
Get PDF石垣島名蔵湾北部では，閉鎖的なラグーン状窪地のコアマモは，分布縁辺域（上限付近および下限付近）と比べて，株長が長く，地上部バイオマス・地下部バイオマスが高かったが，株密度は低かった。6月と2月とで比較すると，株密度は2月の方が高かったが，他のパラメータは6月に高かった。分布縁辺域では，株密度以外のパラメータの月間の違いが小さかった。分布中心域付近での周年調査では，夏季に最大となる株長の消長とほぼ同期して，地上部バイオマスが季節的に変化した。有性生殖は，水温が最も低い2月頃の短期間に行われた。journal articl
Transcriptome analysis of the Japanese eel (Anguilla japonica) during larval metamorphosis
Get PDFBackground: Anguillid eels spend their larval period as leptocephalus larvae that have a unique and specialized body form with leaf-like and transparent features, and they undergo drastic metamorphosis to juvenile glass eels. Less is known about the transition of leptocephali to the glass eel stage, because it is difficult to catch the metamorphosing larvae in the open ocean. However, recent advances in rearing techniques for the Japanese eel have made it possible to study the larval metamorphosis of anguillid eels. In the present study, we investigated the dynamics of gene expression during the metamorphosis of Japanese eel leptocephali using RNA sequencing.
Results: During metamorphosis, Japanese eels were classified into 7 developmental stages according to their morphological characteristics, and RNA sequencing was used to collect gene expression data from each stage. A total of 354.8 million clean reads were generated from the body and 365.5 million from the head, after the processing of raw reads. For filtering of genes that characterize developmental stages, a classification model created by a Random Forest algorithm was built. Using the importance of explanatory variables feature obtained from the created model, we identified 46 genes selected in the body and 169 genes selected in the head that were defined as the "most characteristic genes" during eel metamorphosis. Next, network analysis and subsequently gene clustering were conducted using the most characteristic genes and their correlated genes, and then 6 clusters in the body and 5 clusters in the head were constructed. Then, the characteristics of the clusters were revealed by Gene Ontology (GO) enrichment analysis. The expression patterns and GO terms of each stage were consistent with previous observations and experiments during the larval metamorphosis of the Japanese eel.
Conclusion: Genome and transcriptome resources have been generated for metamorphosing Japanese eels. Genes that characterized metamorphosis of the Japanese eel were identified through statistical modeling by a Random Forest algorithm. The functions of these genes were consistent with previous observations and experiments during the metamorphosis of anguillid eels.journal articl
飼育下における植食性魚類ブダイの摂餌日周性，摂餌量の季節変化および摂餌選択性
Get PDF海藻を餌とした延縄によるブダイの除去の効率化を検討するため，摂餌生態に関する飼育試験を行った。朝（5:00～10:00），昼（10:00～15:00），夕方（15:00～20:00），夜間（20:00～5:00）の本種のヒジキの摂餌量を調べた結果，朝は8.6 ± 4.7 g/kg-fish/h，昼は8.8 ± 3.4 g/kg-fish/h と多く，夕方は5.5 ± 2.5 g/kg-fish/h に減少した。なお，夜間は0.1 ± 0.1 g/kg-fish/h であり，摂餌していないと考えられた。また，ブダイを1年間飼育し，2ヶ月に1回クロメの摂餌量を把握した結果，6～8月の摂餌量は76.9～224.9 g/kg-fish/day であり，他の月（8.4～37.6 g/kg-fish/day）と比較して多かった。さらに，ヒジキ，ウミウチワ，シワヤハズ，パピラソゾ，マクサ，ミルの6種の海藻をブダイに給餌した結果，24時間後の被食率はヒジキが87.2 ± 19.7%となり，他の海藻（2.4～72.8 %）と比較して高い値であった。以上の結果から，延縄でブダイの除去を行う場合，春から初夏の午前中にヒジキを餌として実施すれば効率が良いと考えられた。journal articl