Properties of Edible Films Made From Anchovy By-Product Proteins and Determination of Optimum Protein and Glycerol Concentration by the TOPSIS Method

In the present study, the physicochemical and mechanical properties of films made from anchovy (Engraulis encrasicholus) by-product proteins (ABPs) were characterized as a function of protein (3, 4, and 5%) and glycerol (30, 40, 50, and 60%) concentration. In particular, the thickness, color, transparency, water vapor permeability (WVP), solubility, oxygen permeability (OP), and mechanical properties of the films were measured, and generally, these properties were affected by both protein and glycerol concentration. The thickness, redness, WVP and solubility values of films increased, while their lightness and yellowness values decreased as protein concentration increased. Furthermore, lightness, yellowness, and elongation at break (EAB) values were found to increase at higher glycerol concentrations within ABP films, whereas tensile strength (TS) and elastic modulus (EM) values decreased. ABP films became more transparent with increase of glycerol concentration and decrease of protein concentration. The OP values of all films decreased depending on protein and glycerol concentration. The techniques for order performance by similarity to ideal solution (TOPSIS) method was used to determine optimum protein and glycerol concentrations. According to this method, an edible film containing 4% protein and 40% glycerol was the best film with a C value of 0.6665.     

赤潮异弯藻对鳀鱼早期发育的影响

就赤潮异弯藻(Heterosigma akashiwo)藻液及各组分对鳀鱼(Engraulis ja ponicus)早期发育阶段的影响进行了研究。并就鳃鱼早期发育过程中对赤潮异弯藻的敏感性时期作了探讨。实验结果表明，原肠期前的发育卵和初孵仔鱼对赤潮异弯藻较其他发育阶段更为敏感。在同等条件下藻细胞内容物对鳃鱼早期发育各阶段的毒性最大，其次是藻细胞碎片和藻液，去藻过滤液的毒性最小。暴露在高浓度90000c／ml藻细胞内容物中，96h后仔鱼的存活率为4％；而在同浓度的去藻过滤液中，96h后仔鱼的存活率为75％。藻细胞内容物和藻细胞碎片对鳃鱼仔鱼96hI。C∞分别为2818、6760c／mL．     

秋冬季黄东海区影响鳀鱼行动分布的三大水系变化特征

依据中国和挪威联合进行的黄东海渔业资源声学评估调查资料，并结合历史研究成果，分析了对鱼行动分布有着显著影响的三大水系（黄海冷水团、黄海暖流和苏北沿岸冷水）的变化特征。结果表明，三大水系均具有明显的年际变化。（1）黄海冷水团的温盐性质比较稳定，但其相对体积强年（1986年11月）约为弱年（985年11月）的144倍；（2）黄海暖流的流速强年（1986年1月）约为弱年（1992年正月）的1．21倍；（3）苏北沿岸冷水以3月份势力最强，其强度1985年1月大于1986年1月。     

鳀鱼的生物量、渔业及其生物学特征

IntroductionThe Yellow Sea is characterized by a shallow continental shelf. High tides and seasonally varying mon-soons,freshwater discharge from surrounding landmasses and large amounts of sediments transported intothe sea as well as the effect of the Kuroshio current have strong effects on the environment in these areas.Productivity of an ecosystem may be measured in terms of abundance of the adult population and recruitmentof new year classes.Japanese anchovy(Engraulis jap onicus) is cons…     

黄海鳀鱼鱼体能值的季节变化

根据2002年6月～2003年9月黄海中南部水域鳀鱼的调查资料，分析了产卵、索饵和越冬期鱼体能值的季节变化以及精巢和卵巢能值的变化情况。产卵期(5～7月)、索饵期(8～10月)和越冬期(11～1月)鳀鱼能值的变动情况反应了性腺发育状况。卵巢能值和精巢能值的季节变化趋势相似。幼鱼和成年鳀鱼能值的季节变化趋势相似，但各个月份幼鱼能值均比成鱼低。鱼体能值从越冬期到产卵前期变化很大，达40％～50％，这主要由脂肪含量变化引起。湿重丰满度系数比干重丰满度系数估算鱼体能值准确度差。     

Interannual differences in growth and hatch‐date distributions of early juvenile European anchovy in the Bay of Biscay: implications for recruitment

In order to understand better the recruitment variability in European anchovy in the Bay of Biscay, it is important to investigate the processes that affect survival during the early life stages. Anchovy juvenile growth trajectories and hatch‐date distributions were inferred over a 3‐year period based on otolith microstructure analysis. Otolith growth trajectories showed a characteristic shape depending on their hatch‐date timing. Earlier‐born juveniles had notably broader maximum increments than later born conspecifics, resulting in higher growth rates. This observation suggests that early hatching would be beneficial for larval and juvenile growth, and, therefore, survival. The estimated juvenile hatch‐date distributions were relatively narrow compared with the extended anchovy spawning season (March–August) in the Bay of Biscay and indicated that only individuals originated mainly from the summer months (June–August) survived until autumn. Hatch‐date distributions were markedly different among years and seemed to influence the interannual recruitment strength of anchovy. We conclude that years characterized by juvenile survivors originating from the peak spawning period (May and June) would lead to considerable recruitment success. Downwelling events during the peak spawning period seem to affect larval survival. Furthermore, size‐dependent overwinter mortality would be an additional process that regulates recruitment strength in the anchovy population in the Bay of Biscay.     

黄海鳀鱼的生长特征及其年际与季节变化

利用2001年1月和2004年1月黄海鳀鱼(Engraulis japonicus)越冬群体的生物学资料和千里岩海洋环境监测站1997~2003年海表水温资料,对鳀鱼的生长特征及其年际差异进行了分析,对水温与鳀鱼生长的关系进行了初步探讨;利用2000年6、8、10月和2001年1、3、5月份的调查资料对鳀鱼生长的季节特征进行了分析。结果表明,(1)2001年和2004年鳀鱼的Von Bertanaffy体长生长方程参数L∞、k、t0分别为190.1mm、0.47、-0.06和172.7mm、0.61、-0.17;体重生长方程的参数W∞、k、t0分别为45.4g、0.46、-0.11和35.5g、0.60、-0.21;生长拐点分别为2.35龄和1.72龄。相对2001年,1~3龄鱼的体长和体重积温生长速度增大,4龄鱼的体长积温生长速度相同,体重积温生长速度减小。(2)伴随着群体的补充和个体的生长与死亡,鳀鱼的体长组成具有明显的季节特征。鳀鱼个体的肥满度也存在明显的季节变化,最高值出现在生殖盛期之前的5月,为0.82;最低值出现在越冬期之后的3月,为0.44。     

Pacific sardine (Sardinops sagax, Jenyns 1842) landings prediction. A neural network ecosystemic approach

In this study the performances of computational neural networks (CNNs), multiple linear regressions (MLRs) and generalised additive models (GAMs) to predict Pacific sardine (Sardinops sagax) landings and to analyse their relationships with environmental factors in the north area off Chile were studied. For this purpose several local and global environmental variables and indexes (sea surface temperature, sea level and Ekman transport index in the Chilean coast and, sea surface temperature in the area Niño 3 + 4 and Niño 1 + 2, and the south oscillation index) were considered as inputs or independent variables. Additionally, several CNNs were calibrated and validated adding the anchovy (Engraulis ringens) landings in the same area as model inputs. The time lags of the variables considered were selected through analysis of the non-linear cross-correlation functions and an alternative form of sensitivity analysis based on the approach of the missing value problem. The analysis of error measures with validation data set showed that the best results were obtained when local and global variables were used separately and combined with anchovy landings. Globally, the best result was given by a CNN with 18 input variables (model CNN 6(II) which only considered global variables and anchovy landings) and 10 neurons in a hidden layer. For this configuration the explained variance was slightly higher to 86% which supposed a standard error of prediction of 7.66%. These results were significantly better than those obtained with MLRs and GAMs. The strong correlation between predicted and observed sardine landings suggests that CNNs captured the trend of the historical data. Also, the generalisation capacity together the sensitivity analysis allowed us to identify the variables with a high weight in the model and partially to interpret the statistical functional relationships between these environmental variables and sardine landings.     

黄海中部夏季鳀鱼卵、仔稚鱼分布与早期生长特征

摘 要：鳀（Engraulis japonicus）是黄海重要的捕捞对象，也是蓝点马鲛等大型鱼类的主要饵料。探究鳀早期生活史阶段的生长特征，是深入了解鳀补充机制的重要基础。本研究基于2019年夏季黄海中部断面调查数据，利用Tweedie GAM模型研究了鳀鱼卵和仔稚鱼分布与环境因子的关系，并基于鳀仔稚鱼耳石微结构分析，估算了鳀仔稚鱼的日龄和体长组成，逆推孵化日期，构建幂函数早期生长方程。结果显示，2019年夏季在山东半岛南部35°N断面形成鳀鱼卵的密集分布区，仔稚鱼密集分布区在123.5°E、35.5-36.5°N纵向断面海域。盐度对鱼卵、仔稚鱼的分布都有显著影响，最适盐度范围均在30-32，温度仅对鱼卵的分布有显著影响，最适温度范围在23-26℃。本研究共鉴定和分析211尾鳀仔稚鱼的日龄，体长范围集中在10-22 mm，优势体长组是12-14mm，日龄范围集中在16-30d，优势日龄组是19-21d；耳石增长率范围为3.08-5.90μm/d，分析比较了两个航次鳀仔稚鱼耳石增长率的变化特征，发现耳石增长率的变化趋势具有显著的差异，可能与月份间的温度差异有关。本研究为鳀资源的早期生长和补充机制提供了科学依据。     

山东半岛南部癆鱼产卵场癆鱼仔、稚鱼摄食的研究

研究了山东半岛南部Ti鱼产卵场体长2．5－17．9mm的Ti鱼仔、稚鱼的摄食。Ti鱼仔、稚鱼主要饵料为原生动物的鼎形虫、单角铠甲虫、三角铠甲虫。小型桡足类的卵、桡足类的无节幼体和桡足幼体。桡足类种类为墨氏胸刺水蚤、小拟哲水蚤、克氏纺锤水蚤、双刺纺锤水蚤和拟长腹剑蚤等小型类桡足类。各种饵料所占的个数的百分比为：鼎形虫2．2％，单角铠甲虫7．6％，三角铠甲虫3．3％，桡足类的卵42．2％，无节幼体30．4％，桡足幼体14．1％，Ti鱼仔、稚鱼的摄食率为16．2％，摄食活动主要在白天，在水的中下层进行。由于摄食率低，肠道饱满度差，饥锇可能是引起Ti鱼仔、稚鱼死亡的主要原因。