Spatio-temporal variability in life cycle strategy of four pelagic Antarctic copepods: Rhincalanus gigas, Calanoides acutus, Calanus propinquus and Metridia gerlachei

Spatio-temporal variability in life cycle strategy of four pelagic Antarctic copepods, Rhincalanus gigas, Calanoides acutus, Calanus propinquus and Metridia gerlachei was studied, including their copepodite stage composition, using the multiyear samples taken off east Antarctica (90-160°E) in March 1988-1996. Except for R. gigas, the rare occurrence of adults indicated that the spawning activities ceased by mid-March in this research area. Younger copepodite stages appeared for C. propinquus compared to C. acutus, suggesting the late reproduction or slow growth in the former. Multiple regression analysis on the relationship between environmental variables and the copepodite stage composition showed that the population matured earlier in the warmer area for C. acutus, C. propinquus and M. gerlachei. The study demonstrated that the three species flexibly changed timing of the reproduction and development, and shifted their life cycle from one year to two years in the southern Antarctic Circumpolar Current (ACC) area, responding to spatio-temporal environmental change caused by meandering of the ACC

Report on the Southern Ocean Continuous Plankton Recorder (SO-CPR) Standards Workshop 2016: SCAR SO-CPR Database Expert Group

2016年12月12−16日にオーストラリア南極局にて「南極研究科学委員会（以下SCAR）連続プランクトン採集器（以下CPR）データベース専門家グループワークショップ2016」を開催した．南大洋CPR観測プロジェクトを主導する日本，オーストラリア，ニュージーランドの実務担当者の間で，観測データの品質管理，種同定やデータ分析手法の再確認，および今後の活動についての詳細な討議を行った．前半はこれまでのプロジェクト活動を総括し，各国のマネージメントの状況を確認し，さらには将来的な観測計画を議論した．後半は動物プランクトンの種同定リストの更新のため，具体的な分類カテゴリーの種同定を実施した．特に有孔虫とオキアミ類の幼生期について，確認を行った．まとめられた種同定基準を用いて新たなマニュアル作成を開始することになった．今後，2年に一度を目途にプロジェクト参加国の技術者を集めたワークショップを開催し，各国間で統一された試料処理およびデータ管理を維持していくことを目指すこととなった．The“Southern Ocean Continuous Plankton Recorder (SO-CPR) Survey Standards Workshop”was held at the Australian Antarctic Division on 12−16December 2016. The purposes of the workshop were to confirm that consistent and high standards of species identification, methodology, and data quality were being maintained amongst the main analysts in the SO-CPR Survey, and to discuss future training methods, including a SO-CPR manual that will include a counting rule book, and a future road map for the SO-CPR program. During the workshop we discussed a range of topics including: taxonomic resolution issues (particularly for Foraminifera and euphausiid larval identification and staging); laboratory methods (preservation and storage, with emphasis on maintaining correct pH); shipboard techniques; training methods; data handling (metadata, database, data sharing); gap analysis (spatial, temporal, data, quantitative); and future workshops/conferences, including comprehensive training workshops for emerging SO-CPR survey partners (India). We agreed that there should be a larger workshop every two years to ensure that the high standards of the SO-CPR program are maintained

Report on the Southern Ocean Continuous Plankton Recorder (SO-CPR) Standards Workshop 2018: SCAR SO-CPR Database Expert Group

2018年11月20−23日にオーストラリア南極局にて「南極研究科学委員会，連続プランクトン採集器（以下CPR）データベース専門家グループワークショップ2018」を開催した．本ワークショップは2年に一度を目途に，南大洋CPR観測プロジェクト参加国の技術者を集め，各国間で統一された試料処理およびデータ管理を維持する目的で実施しており，今回は2016年に次ぐ開催であった．プロジェクトを主導する日本，オーストラリア，ニュージーランドの実務担当者の間で，動物プランクトンの種同定リストの更新，それに伴う具体的な分類カテゴリーの同定方法の確認を行った．特に亜南極域に出現するオキアミ類やカイアシ類について情報共有した．後半は観測データの品質管理，データ分析手法の再確認，また各国のマネージメントの状況を確認するとともに，今後の活動についての詳細な討議を行った．特に新規参入国へ向けた技術者育成ワークショップのための，分析手法マニュアル，および動物プランクトン種同定マニュアルの作成へ向けたロードマップを作製し，作業を開始することになった．The “Southern Ocean Continuous Plankton Recorder (SO-CPR) Survey Standards Workshop” was held at the Australian Antarctic Division on 20−23 November 2018. This biennial workshop was last held in 2016. The participants were technicians from the three nations (Japan, Australia, and New Zealand) leading the project. The purpose of the workshop was to ensure that high standards of data quality were being maintained, in terms of species identification and methodology, among the main analysts of the SO-CPR survey, and to discuss future training methods and a future roadmap for the SO-CPR program. A range of topics was discussed including: taxonomic resolution issues (particularly for northern species of copepods and euphausiids), laboratory methods (setting of the CPR cassette, microplastic counting rules), training methods (SO-CPR processing manual and zooplankton counting rule book), data handling for database input, and future standards workshops, including comprehensive training workshops for emerging SO-CPR survey partners. We discussed and agreed on a future roadmap for making a SO-CPR processing manual and zooplankton counting rule book, for the purposes of current and new technician training

Zooplankton distribution patterns in relation to the Antarctic Polar Front Zones Recorded by Continuous Plankton Recorder (CPR) during 1999/2000 Kaiyo Maru cruise

During the 8th Antarctic Expedition of the R/V Kaiyo Maru of the Japan Fisheries Agency, October 1999 to March 2000,a Continuous Plankton Recorder (CPR) was used to investigate zooplankton composition and abundance in the surface of the Indian sector of Southern Ocean between South Africa and Antarctica. Total zooplankton abundance ranged from 0 to 432 individuals/segment (a 5 nautical miles of the surface towing) (Mean±SD=69.7±83.5). Zooplankton abundance tended to be higher in the high latitudes than the Sub-Antarctic Front (SAF). Opposite correlations were observed between zooplankton and seawater temperature (negative), salinity (positive) and in vivo fluorescence value (positive) reflecting the higher abundance of zooplankton found in the cooler waters south of the SAF, which also have higher salinities and phytoplankton. Among twenty-nine species/taxa identified, cyclopoid copepod Oithona spp. were found throughout the transect, and accounted for 53.3% of total zooplankton abundance. Cluster analysis based on seventeen dominant zooplankton species/taxa revealed two groups and three ungrouped individual species/taxa at the 84% dissimilarity level. On the other hand, the cluster analysis based on the samples obtained in a 5 nautical miles indicated two major distinctive zooplankton community groups at 89% dissimilarity level. The main group included most segments in the Polar Frontal Zone (PFZ : region between SAF and the Polar Front) and Antarctic Zone (AZ : south of the Polar Front) with high zooplankton abundance while the second mainly group comprised lower latitude segment with low abundance (<100 individuals/segment)

ナンキョク ケンキュウ カガク イインカイ ノ レンゾク プランクトン サイシュウキ センモンカ グループ ワークショップ ホウコク

2010年11月22-26日に国立極地研究所にて「南極研究科学委員会(以下SCAR)連続プランクトン採集器(以下CPR)専門家グループワークショップ」を開催した.4カ国から12名が参加し,南大洋CPR観測実務担当者の間で,観測データの品質管理,種同定やデータ分析手法の再確認,及び今後の活動についての詳細な討議を行った.前半は文献資料及び顕微鏡観察を通して,動物プランクトンの分類群ごとに種同定の情報交換及び具体的な分類カテゴリーの統一を図った.まとめられた種同定基準を用いて新たにマニュアルを作成することとなった.後半はデータ分析手法とデータマネージメント,さらには将来的な観測計画を確認した.今後,定期的にワークショップを開催し,各国間で統一された試料処理及びデータ管理を維持していくことで合意した."Southern Ocean Continuous Plankton Recorder (SO-CPR) Standards Workshop: SCAR Expert Group on CPR Research" was held at the National Institute of Polar Research (NIPR) on 22-26 November 2011. Twelve participants from four countries attended. The purposes of the workshop were to ensure that consistent and high standards of species identification, methodology, and data quality were being maintained amongst all participants and laboratories in the SO-CPR survey, and to discuss future contributions of the SO-CPR program to a global CPR network. The first three and a half days of the workshop were focused on assessing the accuracy and consistency of species identifications. We concluded that our species identifications and procedures are accurate and uniform, and that the SO-CPR database is of the highest possible standard. Certain taxonomic criteria developed at the workshop will be described in a new laboratory procedures manual. Four major gaps in the database (spatial, temporal, taxonomic, and data analysis gaps) were identified and discussed. Participants concurred that there should be more regular workshops to ensure that the high standards of the SO-CPR program are maintained

Identification of novel subgroup a variants with enhanced receptor binding and replicative capacity in primary isolates of anaemogenic strains of feline leukaemia virus

&lt;b&gt;BACKGROUND:&lt;/b&gt; The development of anaemia in feline leukaemia virus (FeLV)-infected cats is associated with the emergence of a novel viral subgroup, FeLV-C. FeLV-C arises from the subgroup that is transmitted, FeLV-A, through alterations in the amino acid sequence of the receptor binding domain (RBD) of the envelope glycoprotein that result in a shift in the receptor usage and the cell tropism of the virus. The factors that influence the transition from subgroup A to subgroup C remain unclear, one possibility is that a selective pressure in the host drives the acquisition of mutations in the RBD, creating A/C intermediates with enhanced abilities to interact with the FeLV-C receptor, FLVCR. In order to understand further the emergence of FeLV-C in the infected cat, we examined primary isolates of FeLV-C for evidence of FeLV-A variants that bore mutations consistent with a gradual evolution from FeLV-A to FeLV-C.&lt;p&gt;&lt;/p&gt; &lt;b&gt;RESULTS:&lt;/b&gt; Within each isolate of FeLV-C, we identified variants that were ostensibly subgroup A by nucleic acid sequence comparisons, but which bore mutations in the RBD. One such mutation, N91D, was present in multiple isolates and when engineered into a molecular clone of the prototypic FeLV-A (Glasgow-1), enhanced replication was noted in feline cells. Expression of the N91D Env on murine leukaemia virus (MLV) pseudotypes enhanced viral entry mediated by the FeLV-A receptor THTR1 while soluble FeLV-A Env bearing the N91D mutation bound more efficiently to mouse or guinea pig cells bearing the FeLV-A and -C receptors. Long-term in vitro culture of variants bearing the N91D substitution in the presence of anti-FeLV gp70 antibodies did not result in the emergence of FeLV-C variants, suggesting that additional selective pressures in the infected cat may drive the subsequent evolution from subgroup A to subgroup C.&lt;p&gt;&lt;/p&gt; &lt;b&gt;CONCLUSIONS:&lt;/b&gt; Our data support a model in which variants of FeLV-A, bearing subtle differences in the RBD of Env, may be predisposed towards enhanced replication in vivo and subsequent conversion to FeLV-C. The selection pressures in vivo that drive the emergence of FeLV-C in a proportion of infected cats remain to be established

Micro- and meso-zooplankton communities in the seasonal ice zone of the Southern Ocean

第6回極域科学シンポジウム[OB] 極域生物圏11月16日（月）　統計数理研究所 セミナー室1（D305