南黄海春季鳀和赤鼻棱鳀的食物竞争

根据南黄海鳀(Engraulis japonicus)和赤鼻棱鳀(Thrissa kammalensis)及其饵料的碳氮稳定同位素比值,采用IsoSource软件计算了两者饵料的质量贡献比。发现二者食物来源较为一致,其中仔稚鱼对鳀和赤鼻棱鳀的质量贡献率分别为42%~50%和53%~70%,是两者的首要能量与营养源。在获得食物贡献比的基础上,分别采用食物重叠指数法、聚类分析法和稳定同位素法3种方法,针对5种不同的摄食条件,依次对鳀与赤鼻棱鳀的食物重叠度进行计算。其中在饵料平均贡献比条件下,3种方法的计算结果相差不大,都在70%左右,计算偏差≤5%。研究结果表明,两者的食物竞争主要是针对仔稚鱼展开的,两者间存在显著的食物竞争关系。     

基于贝叶斯方法的黄海北部鳀鱼体长与体重关系式参数估计

根据2011年12月,2012年1月、5月、9–11月,2013年5月、9–12月和2014年5月在山东威海市中心渔港、石岛渔港拖网、双岛湾定置网渔获物中采集的鳀鱼(Engraulis japonicus)样本,分别采用相加的误差结构和相乘的误差结构,利用贝叶斯方法估计了黄海北部鳀鱼体长与体重关系式参数a和b,结合以往研究计算鳀鱼体型因子的分布范围。结果表明,贝叶斯方法能够很好地计算参数a和b的估计值及不确定性;偏差信息准则可以从备选模型中选择出合适的模型,将具有相乘误差结构的体长与体重关系式选为最佳模型。春季、秋季和冬季鳀鱼样本的体长(L,cm)与体重(W,g)关系分别为W=6.186×10–3L3.1360,W=4.892×10–3L3.1774,W=4.479×10–3L3.2206。3个季节样本的体长与体重关系曲线差异显著,春季样本的体长与体重关系曲线明显高于秋季和冬季样本的曲线,秋季与冬季样本的体长与体重关系曲线较为接近。全年数据的体长与体重关系曲线会低估春季鳀鱼的体重,高估秋冬季鳀鱼的体重。从1964年至今,鳀鱼参数a没有太明显的变化规律;从2004年起参数b有变大趋势,2004–2014年估计的参数b明显大于以往估计值。20世纪90年代末至今估计的鳀鱼体长与体重关系曲线明显高于20世纪60~80年代估计的曲线,显示着同体长鳀鱼的平均体重较以往变大了。黄海北部鳀鱼全长与叉长的关系为TL=0.0615+1.0908FL,鳀鱼体型因子的分布范围为0.004 73~0.006 60,中位数为0.006 03,鳀鱼体型因子可作为定量描述其体型特征的一个指标。研究结果为探讨鳀鱼对捕捞压力和环境变化的响应机制及鳀鱼资源评估积累了基础参数。     

变水层双拖网瞄准捕捞黄海南部越冬鳀

鳀(Engraulie japonieus)广泛分布于黄、东海,从五十年代起在我国进行过灯光围网、舷提网、中层拖网等的捕捞试验。由于对资源数量、洄游分布缺乏系统调查和鱼群探测手段落后等原因,都未获成功。1984年10月挪威王国政府赠给我国的“北斗”号渔业资源调查船到达后,对黄、东海中上层鱼类资源进行了调查。评估结果认为鳀资源最高达300万吨,年可捕量约50万吨。越冬期间鱼群相对集中,渔场稳定。因此开展鳀变水层拖网试验研究,促进商业性开发具有重要的现实意义。黄海水产研究所从1986年开始承担这一课题,在变水层拖网设计、作业网位控制、渔场探测和瞄准捕捞技术等方面,研究解决了一些技木难点,为采用变水层双拖网捕捞鳀提供了技术保证。     

黄海中南部鳀鱼的生殖力及其变化

根据2002～2004年在山东半岛南部鳀鱼(Engraulis japonicus)产卵场的调查资料和1985～1986年相关历史资料,分析鳀鱼在经过近20年的高强度捕捞过程中,资源衰退导致个体绝对生殖力与叉长、纯重和年龄之间关系的变化,并对两个时期相同个体鳀鱼的生殖力进行比较.结果表明,2002～2004年鳀鱼的个体绝对生殖力为(14 850±579)粒,个体绝对生殖力随叉长、纯重和年龄的变化显著;与1985～1986年同海区、相同叉长范围和纯重范围的鳀鱼相比,2002～2004年鳀鱼生殖力的增大显著.生殖力增加可能是鳀鱼对长期捕捞压力及外部环境变化的适应性的反应.     

黄海鳀鱼限额捕捞的研究

根据10多年在黄海中南部鳀鱼（Engraulis japonicus）越冬场进行的声学／拖网调查生物量评估结果，利用调谐有效种群分析方法（VPA）对黄海鳀鱼资源种群动态进行了分析。研究结果：提出了鳀鱼限额捕捞工作内容和程序框架。并根据2001年鳀鱼生物量情况推荐，F↓（0．1）为0．7时     

黄海海州湾小黄鱼幼鱼的食性及其随体长的变化

根据2008年7月和8月在黄海海州湾海域进行的定点底拖网调查,应用K-W非参数秩检验、卡平方检验和聚类分析等方法,对小黄鱼(Pseudosciaena polyactis)幼鱼(体长20～110mm)的食物组成及其与体长之间的关系进行研究。结果表明,小黄鱼幼鱼摄食的饵料种类有30余种,甲壳类(桡足类、糠虾类和虾类)是主要的饵料类群,在食物中所占的个数百分比为99.50%。优势饵料有真刺唇角水蚤(Labidocera euchaeta)、长额刺糠虾(Acanthomysis longirostris)和细螯虾(Leptochela gracilis)。小黄鱼幼鱼的摄食强度和食物组成随体长的增长都有明显的变化,随着体长的增加,食物中虾类和鱼类的比例有所增加,而桡足类和糠虾类的比例则减少。饵料生境宽度在体长大于80mm后有明显的增加。聚类分析的结果表明,小黄鱼幼鱼在体长达到80mm时,出现了明显的食物转换现象。可以认为,小黄鱼幼鱼食性的转变与其体长密切相关。     

冬、春季黄海不同粒级浮游生物的脂肪酸组成

比较分析了2015年冬季1月和春末5月黄海不同粒级浮游生物的脂肪酸组成,旨在对不同粒级网采浮游生物营养价值进行评价,为海洋鱼类营养补充研究提供基础资料。结果显示,冬、春两季,ω3多不饱合脂肪酸(ω3PUFA)、二十碳五稀酸(EPA)、二十二碳六稀酸(DHA)、20:1+22:1的相对含量以较大粒级浮游生物(500~2000μm)较高;而16:0、18:0不饱和脂肪酸的相对含量以500μm粒级浮游生物较高。冬季各粒级浮游生物的总饱和脂肪酸(SFA)相对含量均高于春季相应值,但MUFA、PUFA、16:1ω7、EPA、DHA、20:1+22:1的相对含量却低于春季。多元对应分析显示,环境因子中海水温度与100~1000μm粒级浮游生物的不饱和脂肪酸MUFA和PUFA含量呈显著的正相关关系(P0.05)。对比冬、春季浮游生物脂肪酸组成与黄海主要经济鱼类的脂肪酸营养组成,初步认为,在冬季,可为鱼类生长提供足够营养的浮游生物的粒级范围相对较窄,主要是500μm粒级的较大型的浮游生物,而在春季,该类浮游生物的粒级范围较广,100~2000μm的浮游动物都可作为鱼类早期生长的有效饵料来源。由此初步推论,浮游生物食性仔稚鱼食物来源的粒级范围在春季比冬季更为广泛。     

黄海区玉筋鱼体长和体重的关系

利用2001年春汛期间黄海区拖网和沿岸定置网玉筋鱼体长和体重资料用三种方法进行拟合,结果表明:预报性回归法所换算的体重值最接近实测值,玉筋鱼体长和体重的关系为Wt=0 7×10-5×L2 9244t(r=0 9673)。     

越冬和产卵洄游期黄海鳀鱼对能量的利用差异

根据2002年6月至2003年9月黄海中南部水域的鳀鱼(Engraulis japonicus)样品，分析越冬和产卵期间鳀鱼能量利用差异。结果显示，各个月份鳀鱼性腺指数(GSI)和腹腔含脂量等级呈负相关。越冬和产卵期间鱼体脂肪消耗速率有显著差异，纯鱼体脂肪消耗速率也有相似变化。摄食期间(3～5月)黄海鳀积累大量脂肪作为能量储备，产卵前期(5月)个别鳀鱼全鱼体脂肪含量超过40％，平均脂肪含量达15％，产卵过后平均脂肪含量水平下降了10％～11％。然而，越冬期间(11～1月)脂肪含量变化幅度很小。产卵期间(5～7月)全鱼体脂肪含最与性腺重量(性腺成熟度为Ⅳ或Ⅴ期)呈显著正相关。叉长和性腺重量(性腺成熟度为Ⅳ或Ⅴ期)也呈显著正相关。越冬期间全鱼体和纯龟体的同体物质(蛋白质)含量比产卵期间低1％-2％。各个月份全鱼体固体物质(蛋白质)含量比纯鱼体低1％左右。越冬期间各叉长组能量变化很小，而产卵期间月能量消耗则随叉长呈指数增长。能量损失主要是脂肪新陈代谢造成，而存储蛋白质主要用于性腺发育，并且在越冬和产卵期间全鱼体的蛋白质含量保持相对常量。     

黄海鳀鱼的卵巢发育

采用组织切片方法和常规目测法对黄海鯷鱼的卵巢发育特征进行了研究,描述了卵巢各发育期的特征,对不同发育期卵巢内卵母细胞的发育时相组成、卵径分布、卵巢两叶及其前、中、后部发育的差异情况进行了分析。结果表明,鯷鱼卵母细胞发育不同步;Ⅱ期卵巢由1～3时相卵母细胞组成,2时相卵母细胞在数量上占优势（66．39／6）;Ⅲ、Ⅳ和Ⅵ期卵巢均由1～4时相卵母细胞组成,其主要区别在于4时相卵母细胞所占比例不同,其中Ⅳ期卵巢中最高（34．8％）,Ⅲ期次之（28．69／6）,Ⅵ期最低（17．8％）;Ⅴ期卵巢由1～5时相卵母细胞组成,已发育成熟的5时相细胞所占比例最高（29．8％）;卵巢由Ⅲ期到Ⅴ期的发育过程中,主要是3、4时相卵母细胞向4、5时相的发育,1、2时相细胞所占比例基本不变。卵母细胞的粒径分布呈明显的峰、谷特征,这与以前对该问题的“浅锯齿状分布”认知有明显不同;Ⅲ和Ⅵ期卵巢内的卵径（长径）呈单峰分布,优势粒径组均为0．5～0．6mm;Ⅳ和Ⅴ期卵巢呈双峰分布,优势粒径组分别为0．2～0．3mm、0．7～0．8mm和0．5～0．6mm、1．1～1．2mm;V期卵巢两个优势卵母细胞群在粒径分布上彼此分离,粒径较大的群内均为水合卵母细胞,呈现出明显的分批产卵特征。鯷鱼卵巢左叶大、右叶小,右／左重量比值为0．71,95％置信区间为（0．67,0．75）;卵巢叶间和叶内部位间卵母细胞的发育状态无显著差异（P〉0．05）。     

黄海Ti鱼限额捕捞的研究

根据10多年在黄海中南部Ti鱼（Engraulis japonicus)越冬场进行的声学／拖网调查生物量评估结果，利用调谐有效种群分析方法（VPA）对黄海Ti鱼资源种群动态进行了分析。研究结果：提出了Ti鱼限额捕捞工作内容和程序框架。并根据2001年Ti鱼生物量情况推荐，F0．1为0．7时，Ti鱼总允许可捕量（TAC）不超过10万t。     

Transport and environmental temperature variability of eggs and larvae of the Japanese anchovy (Engraulis japonicus) and Japanese sardine (Sardinops melanostictus) in the western North Pacific estimated via numerical particle-tracking experiments

Numerical particle-tracking experiments were performed to investigate the transport and variability in environmental temperature experienced by eggs and larvae of Pacific stocks of the Japanese anchovy ( Engraulis japonicus ) and Japanese sardine ( Sardinops melanostictus ) using high-resolution outputs of the Ocean General Circulation Model for the Earth Simulator (OFES) and the observed distributions of eggs collected from 1978 to 2004. The modeled anchovy individuals tend to be trapped in coastal waters or transported to the Kuroshio–Oyashio transition region. In contrast, a large proportion of the sardines are transported to the Kuroshio Extension. The egg density-weighted mean environmental temperature until day 30 of the experiment was 20–24°C for the anchovy and 17–20°C for the sardine, which can be explained by spawning areas and seasons, and interannual oceanic variability. Regression analyses revealed that the contribution of environmental temperature to the logarithm of recruitment per spawning (expected to have a negative relationship with the mean mortality coefficient) was significant for both the anchovy and sardine, especially until day 30, which can be regarded as the initial stages of their life cycles. The relationship was quadratic for the anchovy, with an optimal temperature of 21–22°C, and linear for the sardine, with a negative coefficient. Differences in habitat areas and temperature responses between the sardine and anchovy are suggested to be important factors in controlling the dramatic out-of-phase fluctuations of these species.     

Complete mitochondrial DNA sequence of the Japanese anchovy Engraulis japonicus

ABSTRACT: The complete nucleotide sequence of the mitochondrial genome for the Japanese anchovy Engraulis japonicus (Teleostei: Clupeiformes) was determined. The entire genome was purified by gene amplification using the long polymerase chain reaction (PCR) technique, and products were subsequently used as templates for PCR with 56 fish-versatile primers that amplify contiguous, overlapping segments of the entire genome. Direct sequencing of the PCR products demonstrated that the genome (16 675 base pairs [bp]) contained the same 37 mitochondrial genes (two ribosomal RNA, 22 transfer RNA and 13 protein-coding genes) as those found in other vertebrates, with the gene order being identical to that in typical vertebrates. A major non-coding region between the tRNA^Pro and tRNA^Phe genes (1024 bp) was considered to be the control (D-loop) region, as it has several conservative blocks characteristic to this region.     

Importance of the Shatsky Rise Area in the Kuroshio Extension as an offshore nursery ground for Japanese anchovy (Engraulis japonicus) and sardine (Sardinops melanostictus)

Recent findings suggest that recruitment of Japanese anchovy (Engraulis japonicus) and sardine (Sardinops melanostictus) depends on survival during not only the first feeding larval stage in the Japanese coastal waters and the Kuroshio front but also during the post‐larval and juvenile stages in the Kuroshio Extension. Spatial distributions of juvenile anchovy and sardine around the Shatsky Rise area in the Kuroshio Extension region and the Kuroshio–Oyashio transition region are described, based on a field survey in the late spring using a newly developed mid‐water trawl for sampling juveniles. All stages of anchovy from post‐larvae to juveniles were obtained in the northern Shatsky Rise area. The Kuroshio Extension bifurcates west of the Shatsky Rise area and eddies are generated, leading to higher chlorophyll concentrations than in the surrounding regions in April and May. When Japanese anchovy and sardine spawn near the Kuroshio front or the coastal waters south‐east of Japan, their larvae are transported by the Kuroshio Extension and are retained in the Shatsky Rise area, which forms an important offshore nursery ground, especially during periods of high stock abundance.     

Grouped, stacked rods and tapeta lucida in the retina of Japanese anchovy Engraulis japonicus

ABSTRACT: Morphology of the photoreceptor cells and tapetum of the Japanese anchovy Engraulis japonicus was studied by histologically and by chemical analysis. The Japanese anchovy has a duplex retina. The cones form parallel rows consisting of alternately placed long cones and bifid cones. Both types of cones are intimately associated and form triple units that are regularly spaced along the row of cones. The rods are grouped and stacked. This fish has a retinal tapetum lucidum composed of guanine and hypoxanthine. Three structures of the tapetum lucidum were recognized: platelet, diamond and rod types. Photomechanical changes include movements of the photoreceptor cells and the retinal tapetum. The retina of the Japanese anchovy is thought to be highly sensitive and well adapted to a dim light environment.     

New size measurement for the Japanese sea cucumber Apostichopus japonicus (Stichopodidae) estimated from the body length and body breadth

ABSTRACT:   Anesthetized body length ( La ), an accurate measurement of body size of Japanese sea cucumber Apostichopus japonicus , is measured by using l -menthol anesthetizer but it is difficult to apply La in the field. An estimation method of La from only one simultaneous measurement of body length ( L ) and body breadth ( B ), regardless of the degree of contraction or extension of the body, is proposed. In simultaneous measurement of L and B for each of 150 animals of both the green and the black types of A. japonicus , there were significant negative correlations between L and B in all animals. Further, √( L  ×  B ) was approximately constant regardless of the animals' body form (coefficient of variance: 0.01–0.06). Thus, the regression equations for Le , estimated La , were calculated: the green type, Le  = 2.32 + 2.02 × √( L · B ); and the black type, Le  = 1.34 + 2.12 × √( L · B ). The error values between Le from these equations and La were small. The variances of Le were approximately one-quarter of those of L and half of B . From these, the equations can be used for body size measurements taken in the field.     

山东半岛南部产卵场鳀鱼生殖群体结构及其变化

根据2000~2004年在山东半岛南部鳀鱼(Engraulis japonicus)产卵场多学科综合调查所获得的资料及1991年等相关历史资料,从体长组成、集群特征、年龄结构、性腺成熟度、性成熟系数、性比、摄食强度等多个方面研究了鳀鱼生殖群体结构及其变化特征。结果表明:(1)鳀鱼生殖群体全长组成范围为6~16cm,优势长度9~12cm,长度组成年代际变化明显,生殖群体组成趋向小型化;(2)生殖群体由1~4龄鱼组成,与1991年相比1龄鱼比例增加,生殖群体的平均年龄减小;(3)6月上旬进入产卵盛期,鳀鱼雌性个体性腺成熟度以IV期、VA期占优势,6月下旬IV期和VA期比例减少,VB期和VI-IV期比例增加,7月上旬VI-III期和VI-II期比例占优势,盛产期结束;(4)鳀鱼生殖期间摄食强度较弱,空胃率超过60%。(5)生殖群体按个体大小集群产卵,各群聚优势长度组成存在明显差别,性腺发育程度不一致。本文还对鳀鱼资源衰退给生殖群体结构和种群补充造成的影响进行了初步讨论。     

Simulation of the impact of climate change on the egg and larval transport of Japanese anchovy (Engraulis japonicus) off Kyushu Island,the western coast of Japan

In order to investigate the impact of climate change on egg and larval transport of Japanese anchovy (Engraulis japonicus) off Kyushu Island western Japan, we conducted particle‐tracking simulations on transport success/failure to fishing grounds from 1960 to 2007. The modeled transport success since the mid‐1990s increased and decreased in the offshore and coastal zones, respectively, compared with the 1960s and 1970s. The estimated northward shift of the spawning ground and weakened Tsushima Warm Current contributed to increase in modeled transport success to the offshore zone. Conversely, the weakening trend of the modeled onshore current in the Goto‐Nada Sea combined with the northward shift of the spawning ground resulted in unsuccessful larval transport. These results suggest that fluctuations in juvenile and subadult anchovy catches in this area may be attributable to changes in the physical environment. The present study showed that changes in transport success induced by oceanographic fluctuations related to climate change, have the potential to affect anchovy recruitment off the western coast of Japan.     

Growth of larval and early juvenile Japanese anchovy, Engraulis japonicus, in the Kuroshio-Oyashio transition region

Larvae, juveniles, and adults of Japanese anchovy, Engraulis japonicus , were distributed throughout the Kuroshio-Oyashio transition region off northern Japan as far offshore as 170°E in 1996 and 1997. The growth trajectories of individual larvae and early juveniles were backcalculated using the biological intercept method based on the allometric relationship between otolith radius and somatic length. Mean larval growth rates ranged from 0.49 to 0.71 mm day^–1 in the transition region, and were comparable to those reported from the Pacific coastal waters of central Japan, which is the principal distribution range of E. japonicus . In terms of growth, the Kuroshio-Oyashio transition region seemed to be a favourable nursery area for larval E. japonicus . Larval growth tended to decline from the inshore to the offshore waters in the transition region. Thermal conditions did not show an inshore–offshore trend in the survey area and did not explain the longitudinal trend in growth rates.