海蜇增殖放流大规格苗种培育

在十几年的海蜇放流增殖中,一般都采用伞径规格为15～20 mm的幼蜇。根据几年来海蜇池塘养殖经验,培养大规格苗种养成,可提高50%～60%的成活率。特别是2007年莱州湾海蜇增殖放流大为减产,除自然因素严     

海洋生物资源增殖放流回顾与展望

目前中国的放流苗种遗传质量监测方法尚未建立,导致放流项目在苗种筛选过程中普遍未考查苗种的遗传质量。随着放流规模和范围的扩大,这一盲点将对放流海域的自然种群产生日益严重的遗传威胁。为逐步建立放流苗种遗传质量监测方法,该研究从遗传分歧度、遗传多样性水平、近交程度、遗传信息保持能力4个方面对比了红鳍笛鲷（Lutjanus erythopterus）放流苗种群体与自然群体,对其遗传质量进行了分析。结果表明,两群体间存在微弱遗传分歧（F_ST=0.016 1）;放流苗种群体的遗传多样性水平和有效种群大小低于自然群体,而其近交系数均值与F_IS大于自然群体。上述比较证明,该苗种的遗传多样性素质低于自然群体,在遗传质量方面不能满足增殖放流要求,如果将此苗种进行放流可能产生多种负面遗传影响。从各指标偏差率看,有效种群大小的偏差率最高（-35.34%）是该苗种最突出的遗传质量缺陷。

     

中国对虾放流增殖苗种中间培育技术

自1984年山东省实施中国对虾放流增殖工作以来,中国对虾放流增殖取得了巨大成功。但在几年的放流增殖验收工作中,我们发现有些地区中国对虾放流增殖苗种中间培育的好,有的中间培育差一些,其原因是还没     

斑节对虾增殖放流大规格苗种培育技术研究

为了促进与稳定海南省海洋生态平衡及海洋渔业的健康持续发展,开展了斑节对虾增殖放流苗种培育技术研究,获得平均规格4.0cm以上的虾苗1 600万尾。该文详细介绍了斑节对虾的大规格苗种培育技术,以期为斑节对虾高效健康养殖提供理论依据及科学参考。     

日本的鲍类增殖研究

近十几年，在日本，有关鲍类增殖的研究，广泛普及，进展迅速，卓有成效。所谓鲍类增殖，就是向开放海区，放流鲍类苗种，充实资源，发展生产。     

改善渔业资源环境 长岛实施黑裙鱼增殖放流

近日，烟台市长岛县成功放流了人工培育的65万尾黑裙鱼鱼苗，这是长岛县连续两年实施黑裙鱼人工育苗放流增殖计划。     

放流增殖中的政策问题

放流增殖中的政策问题刘锡山，孟庆祥（辽宁省海洋渔业开发中心，大连１１６０１５）关键词：放流，增殖，政策理论上认为，渔业资源增殖能恢复已衰败的种群，增加种群数量和重建渔业，国内外已报导过少量实例。一个成功的渔业资源增殖，并能长期运行，需要有相应的科学研...     

大连市开展对虾海蜇资源增殖放流

从2005年5月底开始，在辽宁省水产种苗管理局组织下，大连市开展了对虾和海蜇的人工增殖放流。在海洋岛渔场放流人工对虾苗4．5亿尾，占全省放流量的80．4％，其中广鹿岛和王家岛附近海域放流1．1亿尾，这是第一次大规模在海岛放流对虾；放流海蜇苗种为2500万头，其中庄河尖山海域10130万头，瓦房店西杨乡海域1500万头。     

Persistence of external signs in Pacific herring Clupea pallasii Valenciennes with ichthyophoniasis

The progression of external signs of Ichthyophonus infection in Pacific herring Clupea pallasii Valenciennes was highly variable and asynchronous after intraperitoneal injection with pure parasite preparations; however, external signs generally persisted through the end of the study (429 days post‐exposure). Observed signs included papules, erosions and ulcers. The prevalence of external signs plateaued 35 days post‐exposure and persisted in 73–79% of exposed individuals through the end of the first experiment (147 days post‐exposure). Among a second group of infected herring, external signs completely resolved in only 10% of the fish after 429 days. The onset of mortality preceded the appearance of external signs. Histological examination of infected skin and skeletal muscle tissues indicated an apparent affinity of the parasite for host red muscle. Host responses consisted primarily of granulomatous inflammation, fibrosis and necrosis in the skeletal muscle and other tissues. The persistence and asynchrony of external signs and host response indicated that they were neither a precursor to host mortality nor did they provide reliable metrics for hindcasting on the date of exposure. However, the long‐term persistence of clinical signs in Pacific herring may be useful in ascertaining the population‐level impacts of ichthyophoniasis in regularly observed populations.     

Nursery habitat use for larval and juvenile Pacific herring Clupea pallasii in Miyako Bay on the Pacific coast of northern Japan

Fisheries Science - To clarify nursery habitat use for larval and juvenile Pacific herring Clupea pallasii, we collected eggs, larvae, and juveniles at several sampling sites in inner Miyako Bay...     

日本对中西部太平洋鲣鱼资源的利用和研究

鲣鱼属于金枪鱼类,在中西部太平洋热带水域其资源量丰富、产量一直稳定在百万t以上。通过日本对其资源的利用和研究,可以让我国的渔业界有关部门和渔业公司从中获取某些启迪。     

Characteristics of a Pacific herring Clupea pallasii spawning bed off Minedomari, Hokkaido, Japan

ABSTRACT:   The spawning bed selection of herring Clupea pallasii off Minedomari, Atsuta, on the west coast of Hokkaido, Japan, is discussed in relation to the topography of the rocky shore and wave conditions during the spawning season. From 1998 to 2003, herring have spawned their eggs mainly on the leaves of the seagrass Phyllospadix iwatensis Makino in almost the same site on the rocky shore off Minedomari in the Atsuta area. The site is connected to a valley-like feature offshore. Wave conditions were surveyed at Minedomari during the spawning season in 2000 and the wave height was estimated from 1998 to 2003, except for in 2000, using the correlation of wave height between Minedomari and Ishikari Bay New Port, approximately 18 km south-west of Minedomari. Herring spawned under calm conditions, during which the wave height was approximately 0.5 m off Atusta and Aoshima and was 0.18–1.28 m off Minedomari. The distribution of water particle velocity on the sea bottom surface as a result of ocean waves off the Minedomari area, which was estimated based on the wave height and the topography of the coast, suggested herring could swim easily into the shallower area along the valley-like feature off Minedomari. Therefore, topographical features are thought to be one of the reasons why herring have used Minedomari as a spawning bed. Additionally, seepage of freshwater from the bottom, which was observed in this area, could also be the reason why herring spawn in Minedomari repeatedly.     

First report of viral erythrocytic necrosis in Alaska, USA, associated with epizootic mortality in Pacific herring, Clupea harengus pallasi (Valenciennes)

Abstract. Viral erythrocytic necrosis (VEN) has been associated with large epizootics and high mortality in Pacific herring, Clupea harengus pallasi (Valenciennes), from two different locations in south-eastern Alaska, USA. Clinical signs of disease included whirling, pale gills, watery colourless blood, discoloured livers, pathog-nomonic magenta erythrocytic inclusion bodies and histopathological changes consistent with other infectious haemolytic anaemias in higher animals. Transmission electron microscopy confirmed the presence of iridovirus-type particles associated with the cytoplasmic erythrocytic inclusion bodies. Other apparently healthy herring of various age classes from four additional areas in south-east Alaska also had clinical signs of VEN suggesting a wide distribution of the virus in Alaskan Pacific herring populations. Evidence regarding the two herring epizootics indicated that osmoregulatory stress may have precipitated mortalities in fish having severe anaemia caused by the VEN virus. This is the first reported occurrence of VEN in Alaska and the first natural epizootic known to be associated with the disease.     

太平洋鲱和大西洋鲱间的形态变异研究

为阐明太平洋鲱和大西洋鲱种间形态上的差异,应用单因子方差分析、聚类分析和判别分析方法对两种鱼的23个形态学参数进行了研究。单因子方差分析结果表明：14个形态参数平均值存在极显著差异（P〈0．001）,且种群间差异大于种内差异。聚类分析结果显示所有82个个体明显聚成两支。所有23个形态参数的判别分析结果表明,两种间的形态差异极显著（P〈0．001）;利用挑选后的11项参数判别分析,得出判别等式,两种鱼间的形态差异仍然极显著（P〈0．001）,判别准确率100％。所有23个形态参数的差异系数全部小于Mayr的75％法则临界值,表明两个种间形态学上虽然存在一定分化,但分化程度尚未达到亚种水平。作者推测两个种间形态上低水平的分化可能由于分化的时间较短以及相似的生活环境造成的。     

Larval Pacific herring, Clupea pallasii (Valenciennes), are highly susceptible to viral haemorrhagic septicaemia and survivors are partially protected after their metamorphosis to juveniles

Pacific herring were susceptible to waterborne challenge with viral haemorrhagic septicaemia virus (VHSV) throughout their early life history stages, with significantly greater cumulative mortalities occurring among VHSV‐exposed groups of 9‐, 44‐, 54‐ and 76‐day‐old larvae than among respective control groups. Similarly, among 89‐day–1‐year‐old and 1+year old post‐metamorphosed juveniles, cumulative mortality was significantly greater in VHSV‐challenged groups than in respective control groups. Larval exposure to VHSV conferred partial protection to the survivors after their metamorphosis to juveniles as shown by significantly less cumulative mortalities among juvenile groups that survived a VHS epidemic as larvae than among groups that were previously naïve to VHSV. Magnitude of the protection, measured as relative per cent survival, was a direct function of larval age at first exposure and was probably a reflection of gradual developmental onset of immunocompetence. These results indicate the potential for easily overlooked VHS epizootics among wild larvae in regions where the virus is endemic and emphasize the importance of early life history stages of marine fish in influencing the ecological disease processes.     

Ichthyophonus hoferi Plehn & Mulsow in British Columbia stocks of Pacific herring, Clupea pallasi Valenciennes, and its infectivity to chinook salmon, Oncorhynchus tshawytscha (Walbaum)

Pacific herring, Clupea pallasi Valenciennes, collected from three areas of coastal British Columbia were screened for Ichthyophonus by histological examination. The infectivity of Ichthyophonus to juvenile chinook salmon, Oncorhynchus tshawytscha (Walbaum), was examined in laboratory studies. Ichthyophonus was detected in a total of 82 of 356 herring from all three areas. Prevalence in 2000 and 2001 ranged from 10.5 to 52.5% and was significantly lower in more northern (Hecate Strait) samples. Ichthyophonus was detected by histological examination in chinook salmon following oral or intraperitoneal (i.p.) exposure to homogenates of infected herring tissue. Infections in Yukon stock chinook salmon were occasionally associated with mortality and with inflammation in all tissues examined. Infections were detected significantly more frequently in the caecal mesenteries of i.p.-infected compared with oral-infected chinook salmon. The distribution and prevalence of Ichthyophonus isolates among diverse host species may assist in stock identification and in an improved understanding of trophic interactions.     

Viral replication in excised fin tissues (VREFT) corresponds with prior exposure of Pacific herring, Clupea pallasii (Valenciennes), to viral haemorrhagic septicaemia virus (VHSV)

Procedures for a viral replication in excised fin tissue (VREFT) assay were adapted to Pacific herring, Clupea pallasii, and optimized both to reduce processing time and to provide the greatest resolution between naïve herring and those previously exposed to viral haemorrhagic septicaemia virus (VHSV), Genogroup IVa. The optimized procedures included removal of the left pectoral fin from a euthanized fish, inoculation of the fin with >10⁵ plaque‐forming units (PFU) mL^?1 VHSV for 1 h, rinsing the fin in fresh medium six times to remove unadsorbed virions, incubation of the fin in fresh medium for 4 days and enumeration of the viral titre in a sample of the incubation medium by plaque assay. The optimized VREFT assay was effective at identifying the prior exposure history of laboratory‐reared Pacific herring to VHSV. The geometric mean VREFT value was significantly greater (P < 0.01) among naïve herring (1.2 × 10³ PFU mL^?1) than among groups that survived exposure to VHSV (1.0–2.9 × 10² PFU mL^?1); additionally, the proportion of cultures with no detectable virus was significantly greater (P = 0.0002) among fish that survived exposure to VHSV (39–47%) than among naïve fish (3.3%). The optimized VREFT assay demonstrates promise for identifying VHSV exposure history and forecasting disease potential in populations of wild Pacific herring.