丹江口水库太湖新银鱼不同繁殖群体的繁殖特征比较

2010年6月—2011年6月,对丹江口水库太湖新银鱼(Neosalanx taihuensis)不同繁殖群体的繁殖生物学特征进行了比较研究。结果表明:太湖新银鱼在该水库产卵时间为1—5月(春群)和9—10月(秋群);其中春季群体的体长(65.79 mm±6.05 mm)、性腺成熟指数(17.26±6.42)、繁殖力(1851粒±342粒)和成熟卵径(0.62 mm±0.05mm)均显著高于秋季群体(体长(55.04 mm±3.18 mm)、性腺成熟指数(11.72±5.01)、繁殖力(1 067粒±190粒)和成熟卵径(0.53 mm±0.04 mm))(P<0.05);但是两个群体的丰满度指数(101.43±19.71,101.87±11.85)差异并不显著(P>0.05)。春群是丹江口水库太湖新银鱼种群的主要补充者,春群管理与控制应是银鱼种群管理的重点。     

基于Ｂｅｖｅｒｔｏｎ－Ｈｏｌ鲇鱼山水库翘嘴鲌种群管理研究

作者于2007年4月至2008年4月间,在鲇鱼山水库采集翘嘴鲌（Culter alburnus Basilewsky）样本885尾。对鲇鱼山水库翘嘴鲌的种群管理进行了研究,建立了翘嘴鲌的种群管理模型。建立了Beverton-Holt种群管理模型。在目前开捕年龄tc=2龄,自然死亡系数M=0.4654,捕捞死亡系数F=0.5485,生长系数k=0.2331的情况下,鲇鱼山水库翘嘴鲌渔获物的平均体长为29.91cm,平均体重为278.76g,平均年龄为2.05龄;单位补充量渔获量（Yw/R）为467.2851g/尾。建议将鲇鱼山水库翘嘴鲌的捕捞年龄提高到3龄,有效的保护性成熟个体,提高种群补充数量,并目前捕捞强度下渔获量达到最大值,以达到最大经济效益。     

6个竹品种在贵阳市两湖一库区域的引种试验

为丰富贵阳市两湖一库区的竹种多样性,从多个地方引进6个竹品种进行了3年的栽培试验.结果表明:桂竹的多项指标表现均好,是选定的、可以推广发展的竹种.结论:斑苦竹、大明竹和实肚竹可作为备选竹种,合江方竹和金佛山方竹目前还不能进行大量的引种栽培.     

投饵网箱养鱼促进温杖子水库渔业高速增产的生态经济效益分析

温杖子水库按养鱼水面单位面积承受２２００ｋｇ／ｈａ网箱鱼的负载量设置网箱，建立以网箱养鱼为重要环节的水库新型渔业生产结构体系。三年中，水库水面鱼产量（含网箱鱼产量）由１４５．５ｋｇ／ｈａ上升到２６６．７１ｋｇ／ｈａ，年总产量增长１８．３倍；渔业投入资金年利润率达７１．９％；网箱养鱼的投入总能量转换效率提高了６．０３－６．３６％。合理开发和保护了水库渔业资源，促进了温杖子水库渔业的高速增产。     

山东省大中型水库鱼产力的综合评估

1989、1990 两年调查了山东全省有代表性的36座大中型水库的鱼产力性状。根据调查结果用系统聚类法,等级法和回归分析法进行了鱼产力评估。用等级法将这些水库根据鱼产力的高低分成了五级,并以二座经营较好、放养充分的典型水库的多年连续平均鱼产量为基准,根据浮游生物的平均丰度,估计了各级水库的鱼产力依次为 440、370、290、220 和150kg·ha~(-1)。回归分析法的评价结果表明影响这些水库鱼产力相对高低的主要因素是集雨区的土壤肥力、人口密度和植被覆盖率;以及库水的总磷、总氮、电导率、化学耗氧量和浮游生物的丰度,其中又以土壤肥力影响力最强。     

High prevalence of betanodavirus barfin flounder nervous necrosis virus as well as red‐spotted grouper nervous necrosis virus genotype in shellfish

Using two serially executed PCRs, the discriminative multiplex two‐step RT‐PCR (DMT‐2 RT‐PCR) following the detection seminested two‐step RT‐PCR (DSN‐2 RT‐PCR), we found a high frequency presence of BFNNV genotype as well as RGNNV in various domestic and imported shellfish. This was definitely different from the previous reports of outbreaks and asymptomatic infection only by the RGNNV genotype in cultured finfish in Korea. Cultivation of NNV entrapped in shellfish was performed successfully by a blind passage. Thus, in an attempt to elucidate the epidemiology of betanodavirus, experiments conducted on 969 shellfish samples concluded that (i) distribution of NNV genotype, especially BFNNV, in shellfish is clearly different from that found in finfish of the world; (ii) unlike RGNNV, which showed a high rate in summer, BFNNV showed no seasonal variation and this result suggests BFNNVs in the marine environment remain fairly constant throughout the year; and (iii) the entrapped virus in shellfish was alive and culturable in vitro. These results are the first report of high level prevalence of in vitro culturable NNV in shellfish, for both BFNNV and RGNNV, which may present a potential risk in transmitting nodaviruses to host species in a marine environment.     

三峡水库成库期间鱼类空间分布的水声学研究

２００７年４月１８日～５月１日,利用ＳＩＭＲＡＤＥＹ６０回声探测仪（又称鱼探仪）对三峡水库坝前到丰都干流以及９条主要支流进行了水声学探测。采用垂直探测结合“之”字形路线的方法对库区整个水体鱼类的分布状况进行了研究。调查水域长度约有６００ｋｍ,回波数据分成１２３２个片段进行分析。结果表明：在５ｍ以下水层,体长大于６ｃｍ的鱼类在该区域平均密度为５６７．６８尾／ｄａｍ３,且鱼类分布不均匀。在巫山至奉节江段鱼类的密度最低, 密度的平均值和标准误（ｍｅａｎ±Ｓ．Ｅ）为（８．１±０．４７）尾／ｄａｍ３;在忠县到丰都江段密度最高,平均值和标准误（ｍｅａｎ±Ｓ．Ｅ）为（２５９７．０６±１５４．０８）尾／ｄａｍ３。从坝前到丰都,干流鱼类资源量总体上呈现逐步增加的趋势。支流资源量要比干流高。目标强度在－６０～－５０ｄＢ的鱼体大小差异不显著,大于－５０ｄＢ鱼体的平均目标强度在巴东－巫山江段最高,巫山－奉节江段及抱龙河次之。小型鱼体的大小在各江段没有统计学差异,中型和大型鱼体在巴东－巫山江段鱼体个体相对最大,万州－忠县江段以及小江、长滩河等水域鱼类个体相对较小。     

三道河水库浮游甲壳动物群落结构特征的初步研究

研究了湖北省三道河水库２００７年８月至２００８年４月浮游甲壳动物的群落结构及现存量的时空变化。三道河水库６个采样点（Ⅰ ～Ⅵ）共鉴定出浮游甲壳动物８科、１３属、２１种,其中枝角类５科、９属、１４种,优势种为简弧象鼻蟤（Ｂｏｓｍｉｎａｃｏｒｅｇｏｎｉ）、短尾秀体蟤（Ｄｉａｐｈａｎｏｓｏｍａｂｒａｃｈｙｕｒｕｍ）和透明蟤（Ｄａｐｈｎｉａｈｙａｌｉｎ）;桡足类３科、４属、７种,优势种为广布中剑水蚤（Ｍｉｃｒｏｃｙｃｌｏｐｓｌｅｕｃｋａｒｔｉ）和汤匙华哲水蚤（Ｓｉｎｏｃａｌａｎｕｓｄｏｒｒｉｉ）。浮游甲壳动物年平均密度为９２．６个／Ｌ,枝角类和桡足类分别为３６．９个／Ｌ和５５．７个／Ｌ;平均生物量为１．１２６ｍｇ／Ｌ,枝角类和桡足类分别为０．７３７ｍｇ／Ｌ和０．３８９ｍｇ／Ｌ。浮游甲壳动物现存量的季节变化明显,密度和生物量由高到低依次为秋季＞夏季＞冬季＞春季。浮游甲壳动物密度的水平分布差异明显,采样点的密度和生物量由高到低为Ⅱ ＞Ⅵ ＞Ⅲ ＞Ⅰ ＞Ⅳ ＞Ⅴ。     

Activity patterns of largemouth bass in a subtropical US reservoir

Abstract  Nine largemouth bass, Micropterus salmoides Lacepède, >1.5 kg were implanted with radio tags and tracked for 1 year in an embayment of Lake Seminole, Georgia, USA. Most largemouth bass movement was <50 m h⁻¹ in all seasons and at all times of day. During the day largemouth bass were offshore in deeper water near large woody structures and moved little. Movement was lower during dusk and night periods, and a general movement towards shoreline areas was evident. Water depths where largemouth bass were located had bimodal distributions in all seasons and diel periods, with one mode typically at depths <1 m and another around 3 m. Home ranges were typically largest in the summer and smallest in the winter. Largemouth bass appeared to divide their time between an offshore resting area, primarily occupied during the day, and a near-shore area, where foraging presumably occurred, primarily used during low-light periods. The largemouth bass population in Lake Seminole consists of multiple overlapping subpopulations, offering the opportunity for embayment-specific management.     

新疆福海水库浮游植物生态初步研究

于2008年7月(平水期)、10月(枯水期)和2009年5月(丰水期)在福海水库上游、中段和坝前共设9个采样点,对水库内浮游植物群落进行了调查研究.结果:共采集浮游植物8门88种,优势种为小席藻(Phormidittmtertue tentts)、拟菱形弓形藻(Schroederia nitzschioides)、针形...