Effects of temperature and lipid droplet adherence on mortality of hatchery-reared southern hake Merluccius australis larvae     

Claudia A. Bustos  Mauricio F. Landaeta  Enrique Bay-Schmith  Rodrigo Lewis  Ximena Moraga 《Aquaculture (Amsterdam, Netherlands)》2007,270(1-4):535-540

Effects of exogenous (water temperature) and endogenous (lipid droplet adherence) factors were experimentally tested on early survival of southern hake Merluccius australis reared under controlled conditions. Experiments to determine the effect of temperature (10, 12 and 14 °C) on larval growth rates and yolk-sac absorption rates of unfed southern hake were carried out under laboratory conditions. There was no significant differences in growth rates at the temperature range tested (ANCOVA, F = 0.164, p > 0.25), but yolk-sac absorption rates and mortality increased with temperature (ANCOVA, F = 53.84, p < 0.001). A high percentage (between 31 and 81%) of hake eggs showed a lipid droplet not adhered (i.e., freely moving in the yolk, and not located in the posteriormost portion of the yolk-sac). In a second experiment, fed southern hake larvae with the lipid droplet not adhered during embryonic development did not survive after yolk-sac absorption. This study provides the first data on the influence of the lipid droplet absorption on larval survival of cultured hake, and can be used as an early indication of the quality of the batch.  相似文献   

应用栖息地指数对印度洋大眼金枪鱼分布模式研究   总被引：10，自引：0，他引：10  

冯波  陈新军  许柳雄 《水产学报》2007,31(6):805-812

运用分位数回归方法对温度、温差、氧差与印度洋大眼金枪鱼延绳钓钓获率进行二次回归分析,找出最佳上界方程,以最佳上界方程拟合的数值来建立栖息地指数(HSI)模型,从而揭示印度洋大眼金枪鱼栖息地的分布模式。研究表明,温度、温差、氧差与印度洋大眼金枪鱼延绳钓钓获率的最佳上界分位数回归方程分别为HR_(T0.9)=-44.803 7.685T_(0.9)-0.255T_(0.9)~2,HR_(dT_(0.9))=6.234 0.953dT_(0.9)-0.026dT_(0.9)~2和HR_(dO_(0.88))=7.422 4.25dO_(0.88)-0.727dO_(0.88)~2。10°N～10°S间印度洋海域大眼金抢鱼HSI指数达到0.9以上;10°N以北的波斯湾及10°S～15°S海域的HSI指数为0.8～0.9;15°S～40°S之间海域HSI指数介于0.7～0.8,其中50°E～90°E、15°S～25°S间存在一片季节性HSI指数<0.7的区域;40°S以南的海域HSI指数<0.6。  相似文献   

Copepod species diversity and climate variability in the tropical Atlantic Ocean   总被引：4，自引：0，他引：4  

Sergey A. Piontkovski  Michael R. Landry 《Fisheries Oceanography》2003,12(4-5):352-359

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主捕长鳍金枪鱼延绳钓钓具的最适浸泡时间     

宋利明  李冬静  刘海阳  陈平  李杰 《上海海洋大学学报》2014,23(2):290-296

根据2012年9月21日-11月15日库克群岛海域金枪鱼延绳钓海上调查数据,建立了钓钩深度计算模型,分两种起绳方式建立了作业中每一根支绳的浸泡时间计算模型。将钓钩深度以40 m为一层,共分为6个水层(40~80 m、80~120 m、120~160 m、160~200 m、200~240 m和240~280 m),统计每个水层和整个水体内的钓钩数量和长鳍金枪鱼(Thunnus alalunga)的渔获尾数。计算每个水层和整个水体内的钓具浸泡时间,并以1 h为间隔分别统计每个区间的支绳数量及渔获尾数,计算其渔获率。结果表明:(1)二次曲线可拟合浸泡时间与长鳍金枪鱼渔获率的关系,其渔获率随浸泡时间的增加呈现先增后减的趋势;(2)长鳍金枪鱼在40~280 m整个水体、6个水层中渔获率最高的浸泡时间为11.0~11.4 h。建议:(1)主捕长鳍金枪鱼时,尽可能把支绳的浸泡时间设定在10.0~12.0 h左右,以提高捕捞效率;(2)对于漂流延绳钓,整个水体的最佳浸泡时间可代表各个水层的最佳浸泡时间;(3)目标鱼种不同,钓具的最佳浸泡时间也不同;(4)浸泡时间可作为延绳钓钓具有效捕捞努力量。研究结果可用于提高长鳍金枪鱼捕捞效率,为渔业生产和CPUE的标准化提供参考。  相似文献   

东南太平洋智利竹(竹夹)鱼渔业生物学的初步调查研究     

李显森  陈聚法  周立凯  金显仕 《海洋水产研究》2002,23(2)

根据在东南太平洋的探捕调查 ,对所渔获的智利竹鱼 (Trachurus murphyi)群体的构成、叉长与体重的关系 ,年龄与生长的关系和性腺发育等基本生物学特征进行了初步探讨。结果显示 ,渔获智利竹鱼的叉长范围为 1 45～ 61 0 mm,体重范围为 42～ 1 95 0 g,年龄组成为 2～ 1 3龄 ,3～ 4龄鱼为优势群体 ,初次性成熟年龄为 3龄 ,不同年龄个体性腺成熟的节律差异明显  相似文献   

Long-term changes in copepod abundance and diversity in the north-east Atlantic in relation to fluctuations in the hydroclimatic environment   总被引：12，自引：0，他引：12  

Gregory Beaugrand 《Fisheries Oceanography》2003,12(4-5):270-283

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An intraerythrocytic parasite from the spiny dogfish, Squalus acanthias L., from the Pacific Northwest     

A Clewley  R M Kocan  A A Kocan 《Journal of fish diseases》2002,25(11):693-696

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Alternative methods for nutrition research on the southern bluefin tuna, Thunnus maccoyii (Castelnau): evaluation of Atlantic salmon, Salmo salar L., to screen experimental feeds     

M P Bransden  C G Carter  & B F Nowak 《Aquaculture Research》2001,32(S1):174-181

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Considerations of stock structure of yellowfin tuna (Thunnus albacares) in the Indian Ocean based on fishery data     

TSUTOMU NISHIDA 《Fisheries Oceanography》1992,1(2):143-152

Yellowfin stock structure in the Indian Ocean was studied by using industrial tuna longline fishery data. Three types of test variables were used to detect stock structure, i.e., CPUE, age-specific CPUE, and coefficient of variation for size. Time-series data of test variables were compiled for six sub-areas that were arranged by dividing the whole region systematically along longitude lines every 20 degrees. Then time-series data were smoothed by moving averages, and regressed by simple models. Patterns of time-series trends were graphically and statistically compared to classify homogeneous sub-area groups. Two assumptions were (a) that homogeneous stocks exist longitudinally and overlap in adjacent waters, and (b) that test variables within homogeneous sub-area groups are equally affected, and hence patterns of the time-series trends are similar. After graphical screening for significant sub-area groups, analysis of covariance was applied to test homogeneity of regression parameters representing patterns of the time-series trends. By classifying homogeneous sub-area groups, stock structures were determined at the P <0.05 and P <0.50 levels. The P<0.50 level was recognized as a useful criterion for ‘weak’ test variables since masked or vague structures at the P <0.05 level were likely cleared at this level in many cases. Results of this study and past stock structure studies were reviewed and compared. It was concluded that there are two major and two minor stocks of yellowfin tuna. The two major stocks (the western and the eastern) are located at 40^o-90^oE and 70^o-130^oE respectively. The minor stocks are the far western and the far eastern stocks (the latter possibly being a part of the Pacific stock), which are located westward of 40^oE and eastward of 110^oE respectively. Neighboring stocks are intermingled in adjacent waters.  相似文献   

南沙群岛重要珊瑚礁水域鱼类资源数量分布   总被引：6，自引：3，他引：6  

李永振 《水产学报》2004,28(6):651-656

1998年3—5月和1999年5—6月．采用手钓、延绳钓和流刺网3种作业方式在南沙群岛的渚碧、南薰、东门、美济、赤瓜、永署和华阳等7座珊瑚礁水域进行了2个航次的鱼类资源调查。结果表明,7座珊瑚礁水域不同作业方式的鱼类资源相对丰盛度差别较大,其中刺网以永暑礁最高,手钓以华阳礁最高,延绳钓以南薰礁最高;同时．刺网和手钓不同水深区域鱼类资源的相对丰盛度也不相同．其中刺网以11～30m区域最高．手钓以10m以浅和51～80m区域较高;分析认为,造成礁区之间鱼类相对丰盛度差异的主要原因不是初级生产力．而是生态环境因素,主要是礁盘形态和大型海藻的数量。另外．各礁区水域的优势类群有明显不同．这主要与洞穴的大小和数量、大型海藻及珊瑚的种类和数量等生物和非生物环境有关。  相似文献