南海大眼金枪鱼(Thunnus obesus)摄食生态研究

根据2011年12月—2013年2月于我国南海海域采用金枪鱼延绳钓以及灯光罩网调查捕获的大眼金枪鱼(Thunnusobesus)的各项基础生物学以及胃含物的数据,对其摄食生态进行了分析研究。结果表明:(1)南海海域大眼金枪鱼的食物组成包括鸢乌贼、帆蜥鱼、金色小沙丁鱼、飞鱼、竹荚鱼、鲐鱼、小公鱼属、圆鲹属以及不可辨别的鱼类与虾类,其主要饵料生物为鸢乌贼(%IRI=45.21),其次为金色小沙丁鱼(%IRI=21.36)和帆蜥鱼(%IRI=13.72);(2)空胃率与平均饱满指数随季节变化明显,空胃率在春季时会达到顶峰(37.9%),秋季时最低(16.7%),呈先下降后上升趋势,同时平均饱满指数也在春季达到最高值(0.33),随季节下降并稳定于0.1,空胃率随性腺成熟度的提高有明显上升趋势,平均饱满度指数在性成熟度Ⅰ期与Ⅵ期均呈现高值(1.18、1.04);(3) Shannon-Weiner多样性指数H′和Pielou均匀度指数J随季节变化呈现出明显的变化,Shannon-Weiner多样性指数H′随叉长组基本在1.52—1.72之间变化, Pielou均匀度指数J随性腺成熟度的提高有逐步下降的趋势;(4)营养长度(NR)较高,说明其摄食的饵料成分多、氮来源较复杂,基础食物来源(CR)和生态位总空间(TA)的冬季指标值近乎夏季指标的两倍;通过δ15N稳定同位素法计算大眼金枪鱼的平均营养级为4.73。总体上,南海海域大眼金枪鱼主要以头足类和鱼类为食,其摄食习性与季节和个体发育相关,在食物链中处于较高营养位置。     

尺度对人口地图空间分异规律认知的影响

人口地图是人们认知人口分布规律的重要工具,而不同尺度的人口地图造成了读图者对于人口空间分布规律的认知差异。本文通过眼动跟踪的省、县（市）不同尺度下人口地图认知实验,选取注视点数、注视时间、正确个数等眼动参数,进行差异性显著检验,并结合热点透视图,从空间分异规律的角度进行分析。结果表明,不同尺度的人口地图对于读图者的认知影响显著,读图者对人口空间分布特征及人口数量进行认知时,县（市）级尺度人口地图提供了更丰富、直观的空间分布信息,利于读图者对于人口空间分异规律的把握,平均注视点数更小,平均注视时间更短,每道题回答正确的被试个数更多,认知效率更高。本研究揭示了尺度对人口地图的认知影响规律,为多尺度人口地图制图设计与表达提供理论实验参考。     

两种大眼蟹线粒体16S rRNA基因序列分析

测定了宽身大眼蟹和日本大眼蟹线粒体16SrRNA基因部分片段的序列,其长度均为517bp。二者的核苷酸序列A,T,G,C的含量相似:宽身大眼蟹分别为33.3%,35.6%,19.9%,11.2%;日本大眼蟹分别为35.2%,35.4%,18.4%,11.0%。不包括6处插入/缺失位点,两序列间有63个变异位点,核苷酸差异率为12.26%,其中转换32个、颠换31个,转换与颠换比约为1.0。对国内外大眼蟹的24条长度为415bp的16SrRNA基因同源序列进行分析,A+T的平均含量为71.7%,明显高于G+C的平均含量,且存有变异位点171个,简约信息位点137个。中国和日本的日本大眼蟹之间的核苷酸差异率为4.42%,表明二者已有明显的遗传分化;中国的日本大眼蟹与日本的万岁大眼蟹之间的核苷酸差异率仅为0.21%,表明二者有可能为同一物种。上述结果得到了系统发生树拓扑结构的支持。     

基于深度卷积嵌入式聚类（DCEC）的海洋环境特征提取对渔情预报模型的改进研究

In order to improve the forecasting ability of the fishery forecast model for the longline bigeye tuna (Thunnus obesus), we proposed a marine environment feature extraction method based on deep convolutional embedded clustering (DCEC), combined with generalized additive model (GAM) for forecasting the longline bigeye tuna fishing grounds in the Southwest Indian Ocean. We used the MODIS-Aqua and MODIS-Terra sea surface temperature (SST) three-level inversion image data (in days) from January to December in 2018 at 0.041 6°×0.041 6° to construct a DCEC model, determined the optimal number of clusters based on the Davies-Bouldi index (DBI), and extracted the category feature value (F_M) of each month’s sea surface temperature (SST); we used monthly 1°×1° bigeye tuna longline fishery data from January to December in 2018 generated from the Indian Ocean Tuna Commission (IOTC), and calculated the catch per unit effort (CPUE); we matched the monthly category feature value F_M and the monthly average value of Chl a concentration with the CPUE data to construct an improved GAM; we matched the monthly average SST, the monthly average Chl a concentration and CPUE data to build a basic GAM; we used the joint hypothesis test (F test) to verify the influence of model explanatory variables; we used akaike information criterion (AIC), mean square error (MSE), and draw the frequency distribution diagrams and box diagrams of measured and predicted values, etc., to analysis the improvement effect of the improved GAM compared to the basic GAM. The results showed that: (1) the category feature value (F_M) extracted based on the DCEC model could better reflect the temporal and spatial dynamic characteristics of SST in the Southwest Indian Ocean, and was related with the climatic conditions, monsoon conditions, and hydrological characteristics in the Southwest Indian Ocean; (2) the factor interpretation of F_M was higher than that of the monthly average SST in GAM, which means F_M had more significant impact on the CPUE of bigeye tuna. The high catch rate was concentrated in the areas where the F_M category was 2, 10, 24 with intersections between the warm and cold currents; (3) the AIC of the improved GAM was reduced by 9.17% than that of the basic GAM and MSE of the improved GAM was reduced by 26.7% than that of the basic GAM; the frequency distribution of the CPUE logarithmic value predicted by the improved GAM was closer to the normal distribution, and the high frequency distribution interval was closer to that of the measured value; the scatter plot showed that the CPUE predicted by the improved GAM had a significant correlation with the measured CPUE, with r equaled to 0.60. This study proves the effectiveness of the DCEC model in extracting marine environmental features, and can provide a reference for the further study on the bigeye tuna fishery forecast.     

对2005年12月4日日本海极地低压的个例分析

利用GOES(Geostationary Operational Environmental Satellite)-9红外卫星云图和NCEP(National Centers for Environmental Prediction) 发行的 FNL(Final Analyses) 客观分析资料以及潜热通量资料,对2005年12月4日发生在日本海上空的1个极地低压的时空特征进行了研究.首先根据卫星云图特征,对该极地低压的演变过程进行了分析,可以划分为初始、发展、成熟和衰亡4个阶段.极地低压发展前,大气的斜压性较强,高空伴随有很强的冷平流.在卫星云图上,成熟时的极地低压伴随有螺旋云系,并有明显的眼区,眼区为无风区,且眼区中心附近有很强的上升气流.该极地低压具有暖心结构,眼区周围的气压梯度很大,大风区位于低压中心的西侧.在极地低压发展和成熟阶段,其中心附近的潜热通量可达到220 Wm2.     

眼斑拟石首鱼的生化组成及预测模式

测定了养殖眼斑拟石首鱼肌肉及鱼体中的蛋白质、脂类、灰分和水分等生化组成。分析了肌肉蛋白质中17种常见氨基酸的含量。建立了以鱼体体重、体长、含水量与蛋白含量、脂肪含量、灰份、比能值的回归关系的预测模型。回归结果表明，眼斑拟石首鱼的鱼体组分与鱼体重、含水量间呈显著线性相关，而与全长则呈乘幂函数，基本呈立方关系，比能值与体重无相关性，其相关系数蛋白质＞水份＞灰分＞脂肪＞比能值。     

Typhoon Winnie （1997） with a Very Large Eye： High Resolution Numerical Simulation

Typhoon Winnie (1997) was one of the hurricanes that had extremely large eyewall ever recorded with a diameter of eyewall reaching 370 km. Using the Penn State University/National Center for Atmospheric Research mesoscale model MM5 with 3-km grid horizontal spacing on the finest nested mesh, Winnie was successfully simulated in terms of track, intensity, eye and concentric eyewalls. The dynamic and thermal structures of concentric eyewalls were studied based on the model output. It was found that the concentric eyewalls and their surrounding wind fields were asymmetric in observation as well as in simulation. Winnie's outer eyewall was associated with a maximum wind ring, a warm moist ring, and a high vorticity ring. The inner eyewall was associated with a secondary maximum wind ring and a warm moist ring. Upward motion dominated the whole layer of inner eyewall and the area above 2-km altitude of the outer eyewall. Downward motion was found inside the eye and the moat. Radial inflow happened in the boundary layer of the outer eyewall and the moat, but radial outflow dominated the middle and upper levels of the outer eyewall.     

基于GIS的印度洋大眼金枪鱼延绳钓钓获率与水温关系的研究

采用GIS定性分析和数值分析的方法，研究了印度洋大眼金枪鱼延绳钓钓获率与水温的关系。结果表明，大眼金枪鱼延绳钓高钓获率的出现与印度洋加权水温大面分布存在明显的相互关系，大眼金枪鱼的渔获适温在14～17℃间。建议测量200m水深处的水温作为海上生产时的参考。     

大眼鲷匹里虫病及匹里虫一新种的研究

从我国南海大眼鲷科(Prlacanthidae)的两种大眼鲷——长尾大眼鲷(Priacanthns tayenus)和短尾大眼鲷(P．macracanthus)上发现了一种匹里虫(新种)，定名为大眼鳎匹里虫(Pleistophora priacanthusis sp．nov．)。本文报道了感染鱼的征象、感染率和感染强度、感染部位和对寄主的影响、季节分布和性别差异的情况，并对大眼鲷匹里虫的孢囊、孢子、产孢体、新种的特征作了详细的描述。