The fishes of Saint Helena Island,South Atlantic Ocean. II. The pelagic fishes

The pelagic fishes of St Helena Island, South Atlantic Ocean (15°58′S 5°43′W) are reviewed. A checklist of 53 taxa of pelagic fishes, with notes on fisheries significance, ecology and geographical distribution, is presented. Twelve of the taxa have not before been recorded at St Helena. Of particular interest are records of three primarily Indo-Pacific species: Decapterus muroadsi (Temminck and Schlegel), Uraspis helvola (Forster) and Scomberomorus commerson (Lacepède). Apart from U. helvola, which is known also from Ascension Island, these species are not otherwise recorded in the Atlantic Ocean.

Of the 49 pelagic fishes whose identities are clear, 81·6% are wide-ranging species known from both the Atlantic and Indo-Pacific regions, 12·2% are pan-Atlantic warm-water species and 4·1% are eastern Atlantic species which reach their western limit in the central Atlantic. In addition, the subspecies Platybelone argalus trachura is found only at St Helena and Ascension.

The principal pelagic species caught by St Helena fisheries are Katsuwonus pelamis, Thunnus albacares, T. obesus, T. alalunga, Scomber japonicus, Acanthocybium solandri and Pseudocaranx dentex, which together accounted for almost 95% of fish landings in 1982–1983 fiscal year.     

Deep-sea Tanaidacea (Crustacea) of the North-east Atlantic: the tribe Agathotanaini

The tanaidacean tribe Agathotanaini, which was formerly the family Agathotanaidae, is well-represented in the Rockall Trough and Bay of Biscay areas of the North-east Atlantic. Five species have been recorded from depths of 1160–4829 m. Agathotanais ingolfi is the most numerous and one of the most widely distributed tanaidacean species in the region, and is often predominant in epibenthic sled samples from 1500–2500 m. Less numerous and frequent are three new species of Paragathotanais: P. nanus, P. robustus and P. gracilis. The first two are bathyal in distribution, and the last is abyssal. A new monospecific genus is established for Metagathotanais insulcatus, which has been recorded from the deepest part of the study region (4600–4800 m). Males of this tribe are characterized by their rigid pleopods bearing short terminal setae, and are otherwise very similar to the females. A key is provided for the identification of agathotanaids from the North-east Atlantic, including Agathotanais hanseni, and the genera Allodaposia and Paranarthrura, which should also be classified in the Agathotanaini.     

深海柔性立管弯曲加强器力学建模及参数敏感性分析

柔性立管系统在深海资源开发中使用越来越广泛。弯曲加强器作为立管系统的重要构件,其设计和研究对立管系统在复杂工况下的正常作业有着十分重要的意义。同时考虑材料的非线性力学行为、几何大变形,以及弯曲加强器与立管之间的接触摩擦,建立典型三段式弯曲加强器-立管系统的三维非线性力学模型,并与工程常用线性简化模型结果进行对比,说明非线性力学建模的必要性。在此基础上,通过非线性计算对典型三段式弯曲加强器的关键结构设计参数进行敏感性分析。结果表明,弯曲加强器的各段长度比例、厚度等结构参数对系统工作性能都有一定影响,在弯曲加强器设计时应给予充分考虑。     

水产动物细胞培养方法及前景

综述了鱼虾贝类等水产动物细胞培养的方法,分析了动物细胞大规模培养过程中的问题与对策,展望了动物细胞培养的广阔前景.     

独龙江中下游流域的鱼类区系

独龙江流域位于云南省的西北部,北与青藏高原相连,西与缅甸毗邻.中国科学院昆明动物研究所于2004年10月~11月对该水域鱼类资源进行了具体调查,共计采集到鱼类标本883号,分别属于鲤形目、鲇形目;裂腹鱼亚科、野鲮亚科、鮡科;共2目、3科(亚科)、6属、7种.对独龙江鱼类区系与其相邻水系的鱼类区系进行比较分析,认为独龙江水系的鱼类区系与怒江水系的鱼类区系有着更近的渊缘关系.     

垂直扬矿管道堵塞条件下的水力特性

基于试验研究,探讨了不同颗粒粒径( d)、堵管高度( H)、流体平均流速( V)条件下粗颗粒在垂直扬矿管道中堵管后再起动的临界条件。研究结果表明：( a) d和H是影响单位长度压差(驻P)与V关系的2个重要参数。( b)当驻P与V呈线性关系时,垂直管道堵管后颗粒将无法实现再起动;反之,如若二者呈非线性关系,则颗粒可实现再起动。( c)基于试验结果提出的颗粒再起动时的临界流速、临界单位长度压差计算公式符合精度要求。     

Deep-sea pollen research in China

This paper briefly presents the progress of deep-sea pollen research in China since the beginning of ninetieths of the last Century. All the deep-sea pollen contri-butions mainly come from the South China Sea (SCS) and the East China Sea (ECS). The German-Chinese joint cruise (Sonne 95) and ODP 184 cruise initiated by Chinese scientists in the SCS provided excellent material for the deep-sea pollen research. So far a number of pollen results of 20-30 ka and million years from the SCS have been published. A couple of deep-sea pollen records from Okinawa Through of the ECS also came out. The high resolution pollen records obtained from the continuous deposits with high sedimentation rates and reliable age control of the deep-sea sediments provided a high time resolution history (hundred to millennial scales) of vegetation, environment and monsoon evolution of the pollen source areas (southern China and Japan). Spectral analysis of deep-sea pollen records from the SCS discovered orbital (100, 41, 23, 10 ka) and suborbital cyclicities(Heinrich and Dansgaard/Oscheger-O/D events) in the vegetation changes. Moreover, cross spectral analysis showed that the trend of vegetation changes in northern SCS was regulated mainly by changes of the ice volume in the Northern Hemisphere. The pollen record of the last 20 ka from the Okinawa Through of the ECS indicates that the marine environmental change lagged that on the terrestrail by about 1000 year. The asynchronous environmental changes between land and sea were probably caused by the time difference in thermohaline circulation. This study underscored the role of the deep-sea plant fossils as a bridge across the land and sea.     

A revision of the Labiidae (Dermaptera) of the Neo-tropical and Nearctic Regions

A new genus, Helenolius (Cixiidae, Pentastirini), is described to accommodate the species H. dividens (Walker) comb. nov. and H. insulicola sp. nov. Both species are described and illustrated; they are endemic on the island St Helena.     

Pœcilostomatoid copepods parasitic on fishes off the west coast of Africa

Three species of fish-parasitizing poecilostomatoid copepods are redescribed based on material collected off the coasts of Mauritania and Senegambia. They are: Bomolochus unicirrus Richiardi from Lichia glauca Linnaeus, Taeniacanthus balistae (Claus) from Balistes capriscus Gmelin, and Chondracanthus brotulae Capart from Molva molva (Linnaeus).     

Deep-sea halacarids (Acari) and description of a new species

The number of halacarid genera and the approximate number of species in deep and shallow waters are listed, together with the halacarid species recorded from depths of over 1000 m. The vertical and horizontal distribution of genera are discussed, as well as morphological adaptions to life in the abyss. Eurybathic species are rare, and endemic deep-sea genera presumably do not exist. Algibiont and arenicolous genera have not been found in the abyss. Striking morphological features such as long legs, epimeral and anal protuberances, and dense coatings with cuticular filaments are independent of water depth and hydrostatic pressure, but correlate with life in very soft sediments. The deep-sea species, Lohmannella cygna nov. spec., is described.