辽东湾水域小黄鱼的生长特征

根据2012-2013年在辽东湾水域进行的6个航次的底拖网调查资料,采用体长频率分析法研究了该水域小黄鱼(Larimichtlys polyactis)的生长特征。结果表明,2012-2013年间共采集小黄鱼样本2 593尾,体长范围为40~210 mm,平均体长为115 mm,优势体长组为90~130 mm,占59.3%。体长与体质量的关系式为W=3×10~(-5)×L~(2.8424)。采用ELEFAN技术计算了小黄鱼的Von-Bertalanffy生长方程,其极限体长L_∞、生长系数K分别为260 mm和0.47。种群总死亡系数Z、自然死亡系数M和捕捞死亡系数F分别为2.31、0.41、1.90。与辽东湾及其邻近水域的历史数据相比,辽东湾水域小黄鱼的生物学特征与2000年前发生了较大变化,极限体长减小,生长速度加快,群体小型化和低龄化严重。2012-2013年辽东湾水域小黄鱼的资源开发率为0.823,其资源处于过度开发状态。     

长江干流圆口铜鱼的年龄与生长研究

采用鳞片材料对采自长江干流宜昌和重庆江段圆口铜鱼（Coreius guichenoti）的年龄进行鉴定,并对其生长方程、生长拐点等生物学特征进行了研究。结果表明,调查江段圆口铜鱼的年龄组成以1、2龄个体为主;体长（L）和鳞径（R）呈线性关系,L=15.327R＋71.349;体重（W）与体长（L）呈幂指数关系,W=0.00002L2.9942;体长von Bertalanfy生长方程为Lt=730.15[1-e-0.12（t＋1.01）];体重生长方程为Wt=7493.05[1-e-0.12（t＋1.01）]2.9942;其生长拐点年龄为8.13龄。圆口铜鱼体长生长3龄前为快速期,之后生长减缓。为了保护长江干流圆口铜鱼资源,建议以278mm为最小捕捞个体的体长。     

北部湾二长棘鲷生长和死亡参数估计

根据上世纪90年代及60年代的生物学资料，运用体长频率分析法估算二长棘鲷的生长和死亡参数。vonBertlanffy生长方程的主要参数L∞=27．3cm，K=0．45，t0=-O．34；体重的生长拐点为2．12龄；瞬时总死亡率(Z)、瞬时自然死亡率(M)和瞬时捕捞死亡率(F)分别为2.825，1．045和1．78。当前开发率为0．63，资源处于过度利用状态。根据等渔量曲线图分析，当前的捕捞强度过高，而开捕年龄和开捕体长过低，资源出现衰竭现象。综合考虑当前的捕捞强度和社会经济效益，建议北部湾二长棘鲷的最适开捕年龄大于1龄，开捕体长大于120mm。     

东海北部哈氏仿对虾的种群动态及其最高持续渔获量

哈氏仿对虾是东海北部主要的拖虾渔业对象。在雌性的体长组成中，70－90mm的个体占优势，占总数的63％。应用ELEFANⅠ和ELEFANⅡ技术对哈氏仿对虾每月的体长资料进行分析，结果表明：生长参数K＝1.7，极限体长L∞＝128mm，自然死亡系数M＝2.7427，总死亡系数Z＝8.323，利用率E＝67.06%，极限年龄为1.3234岁，选择体长为59.67mm，补充类型为二季补充型。通过单位补充量产量Y／R和单位补充量产值Yv/R分析表明，该群体的利用已到了相当充分的水平，若保持现有的捕捞水平，把开捕体长增大至70mm时，单位补充量产量可增加1.77%，产值可增加10.78%。但若捕捞死亡水平继续增加，产量几乎不再增加，而产值却明显下降。     

北部湾口海域深水金线鱼生长和死亡研究

2007年1-12月在北部湾口采集477尾深水金线鱼标本,使用FiSATⅡ软件中的ELEFANⅠ程序包对其生长参数进行了估算.一维方差分析结果表明,北部湾口海域深水金线鱼体长和体质量相关性无显著性性别差异（P>0.05）,雌、雄混合后的体长和体质量关系方程为mt=5.4604×10-5L2.875t;Von Bertalanffy生长方程为Lt=244.7×{1-exp[-0.42×(t+0.37)]},mt=402.3×{1-exp[-0.42×(t+0.37)]}2.875;体质量生长拐点2.3龄,对应体长163.1 mm;逻辑斯蒂方程求解的50％性成熟体长为121.5 mm;体长组成资料的累计渔获量曲线估算的总死亡系数为2.28,Pauly经验公式计算自然死亡系数为0.49,北部湾口海域2007年深水金线鱼的开发率达到0.79,资源处于过度开发状态.Beverton & Holt模型研究表明,当前北部湾口海域深水金线鱼的开捕年龄偏小.建议在当前捕捞力量下,增大tc至2龄,此时深水金线鱼体长为152.3 mm,单位补充量渔获量可达到68.5 g/尾.     

闽东北外海渔场银方头鱼Branchiostegus argentatus(Cuvier)渔业生物学初步研究

闽东北外海底层流刺网作业渔获的银方头鱼群体由Ⅰ-Ⅺ龄11个世代构成，以Ⅱ、Ⅲ和Ⅳ龄占优势；体长优势组为210-270mm，体重优势组为200-400克，体长与体重的关系W=2.1120×10-5×L2.9964，r=0.9970。初次性成熟年龄为Ⅱ-Ⅲ龄，最小性成熟个体体长为190mm，在4-8月均有产卵活动；按VonBantanffy方程拟合生长参数L∞=436.21mm，W∞=1715.05g，K=0.2357，t0=-0.9542，体重生长拐点年龄为3.702龄。     

东海中华管鞭虾种群动态及持续渔获量分析

中华管鞭虾为东海区桁杆拖虾和沿岸定置张网作业重要的渔获对象。本文根据2006-2008年桁杆拖虾监测调查数据整理的各月体长频率数据,应用FiSATⅡ软件分析结果表明：Von Bertalanff生长方程的参数K=1.2,极限体长L∞=112.88mm,t0=0.267;根据Pauly经验公式估算的自然死亡系数M=2.03606;由变换体长渔获曲线法估算的总死亡系数Z=4.71,利用率E=56.77%,开捕体长Lc=65.32mm;应用体长VPA方法估算的年平均资源量为47.74×10^9ind、2.58×10^4t。通过单位补充量产量、产值分析表明,该群体利用合理,开捕体长亦处最佳位置,若降低10%左右的捕捞努力量水平,既能使产值最大化（4.92亿元）,又能实现中华管鞭虾的可持续利用。     

洞庭湖花■的年龄、生长和资源评估

根据2017-2019年在洞庭湖采集的228尾花[鱼骨](Hemibarbus maculatus)样本,使用耳石和鳞片研究其年龄、生长和资源现状。结果显示:耳石和鳞片是良好的年龄鉴定材料,鳞片上年轮特征以普通切割型为主,耳石重量可用于粗略、快速年龄鉴定。样本体长90~262 mm,优势体长组120~180 mm;体重11.0~399.0 g,优势体重组为20.0~80.0 g;年龄组成1~4龄,1龄为优势年龄组。体长体重关系:W=7.434×10^-6 L s 3.165,b值显著大于3,为异速生长鱼类。Von Bertalanffy生长方程:L t=301.4[1-e-0.471(t+0.341)],W t=522.0[1-e-0.471(t+0.341)]3.165,拐点年龄2.11龄(体长206.2 mm,体重156.9 g)。花[鱼骨]为典型的r-选择鱼类,总死亡系数3.321,自然死亡系数0.823,开发率为0.752,种群处于过度开发状态。建议起捕体长为172.2 mm,开发率降至0.601,同时在繁殖季节设置人工鱼巢,以恢复洞庭湖花[鱼骨]种群资源。     

东海北部、黄海南部黄鮟鱇的年龄和生长

利用黄鮟鱇Lophius litulon耳石对2007年3月~2009年5月取自东海北部、黄海南部黄鮟鱇的年龄和生长特征进行了分析。结果显示,黄鱼安鱼康群体由1~5龄组成,以1~2龄鱼为主,捕捞群体呈低龄化;生长特点属均匀生长型,体重与体长关系为W=1.55897×10-5L3.10865,体长与耳石半径关系为L=244.11R-210.6,体长生长方程为Lt=749.9[1-e-0.349(t+0.256)],体重生长方程为Wt=13496.4[1-e-0.349(t+0.256)]3.10865,极限年龄Tmax为8.337龄,生长拐点年龄ti为2.994龄,此时对应的体长和体重分别为508.8mm和4038.7g。为保护黄鮟鱇资源,应限捕体长在500mm以下的个体。     

衡水湖红鳍原鲌的年龄、生长和繁殖特性研究

为研究衡水湖红鳍原鲌(Cultrichthys erythropterus)的年龄、生长和繁殖特性，在衡水湖采集261尾红鳍原鲌，测定其年龄、体长、体重、性腺发育时期、性腺重等。结果表明，衡水湖红鳍原鲌的2～3龄为优势龄组，从4月份开始，随着气温的逐渐回升，平均年龄呈现出缓慢上升的趋势，到6月份达到了最高，为1.95,之后从7月份开始又逐渐降低。红鳍原鲌的体长范围为76～238 mm,均值为119 mm;体重范围为5.5～113.1 g,均值为24.6 g。红鳍原鲌的雌性个体为正异速生长，雄性个体为负异速生长。红鳍原鲌的雌雄种群性比为0.903∶1,体长150 mm以下种群，雄性个体占据优势(雌雄比0.87∶1);体长150 mm以上的种群，雌性个体占据优势(雌雄比1.36∶1)。衡水湖红鳍原鲌的繁殖期为4—9月，主要集中在6—7月。卵径范围为0.30～1.20 mm,主要集中在0.60～1.00 mm,根据卵径的变化趋势推测其产卵类型为分批产卵。     

RNA–DNA ratio of herring and sand lance larvae from Port Moller, Alaska: Comparison with prey concentration and temperature

A key assumption of hypotheses that link the production of prey for larval fish with year-class strength of fish is that larval growth and condition is food-limited. We tested this assumption by comparing whole-body RNA-DNA ratios of individual Pacific herring, Clupea pallasi , larvae and Pacific sand lance, Ammodytes hex-apterus , larvae from Port Moller, a subarctic Alaskan estuary, with prey concentration and temperature. RNA-DNA ratios were correlated with larval length, but not with prey concentration or temperature. Ratios were not significantly different between a warm, well-mixed station with low prey concentrations and a colder, stratified station with higher prey concentrations. Using RNA-DNA ratios, we classified as starving 11 to 23% of first-feeding (< 13 mm long) herring larvae and 45% of first-feeding (< 7 mm long) sand lance larvae. However, starvation could not have been caused by low concentrations of prey because micro-zooplankton prey concentrations were high enough (16 to 84 prey L^_l) to support relatively high rates of growth. Therefore, starving larvae were either abnormal or they were stIII learning to forage. We conclude that the magnitude of starvation among first-feeding herring and sand lance larvae, and, therefore, the total contribution of starvation to year-class strength, is dependent not only on prey concentration, but on the proportion of a population of larvae that can feed effectively.     

Interannual decrease in condition factor of the western sand lance Ammodytes japonicus in Japan in the last decade: Evidence for food‐limited decline of the catch

Annual catch of the western sand lance Ammodytes japonicus in the eastern Seto Inland Sea, Japan, has shown a decreasing trend since the 1990s. To examine whether food shortage was the main cause for the catch decrease, we investigated the condition factor of the age‐0 fish at the beginning of the estivation period (late July) in Harima‐Nada, eastern Seto Inland Sea, for 10 years from 2008 to 2017. The mean abundance of copepods as food for the age‐0 fish during the fish growth period (from February to June) around the estivation area was also determined. The condition factor showed a significant decrease, and values for 2011 and later years were mostly lower than the known minimum threshold (4.2) for maturation. In the recent 4 years from 2013 to 2016, the mean copepod abundance was much lower than values for the other years. The condition factor showed a significant positive correlation with the copepod abundance. These results indicate that decline of western sand lance catch after 1990 was caused mainly by food shortage.     

A numerical analysis of population dynamics of the sand lance (Ammodytes personatus) in the eastern Seto Inland Sea, Japan

The Japanese sand lance (Ammodytes personatus) population in the Seto Inland Sea shows large fluctuations every few years. Its recruitment to the fishery resources is much more dependent on the survival rate of 0-age fish than is the case for other fish species because 0-age fish directly recruit to next-year spawning adults. Since the 0-age fish population depends on its larval population, which is easily influenced by natural and human impacts, high larval mortality due to predation by adults and high dispersion of larvae by wind-driven currents from spawning grounds to other locations can have very important effects on stock fluctuations. A numerical model of population dynamics of the sand lance in the eastern Seto Inland Sea was developed that focuses on wind-induced transport and adult predation of the larvae. The model successfully simulated the two-year periodic fluctuation and was consistent with actual fluctuations in fishery catches. It suggests that the various coefficients given in the model are appropriate to explain the actual population dynamics of the sand lance. The model shows that adult predation on the larvae plays a very important role in the two-year periodic fluctuation, and the maximum predation rate is estimated to be ten individuals per day. Wind-induced transport modifies the impact of this predation. Variances in the two-year periodic fluctuation become smaller with weaker westerly wind velocity. The appropriate transport rates from Bisan Strait and the Harima-nada Sea are estimated to be 0.04 d^-1 and 0.01 d^-1, respectively.     

Growth and survival response of the Catarina scallop Argopecten circularis (Sowerby) to stocking density and length of culture period

Growth and survival of the Catarina scallop, Argopecten circularis (Sowerby), were determined in relation to stocking density and length of culture period. Data were analysed by means of the von Bertalanffy growth equation and the weight-length allometric relationship. A mortality equation was empirically derived from the experimental data. Stocking density significantly affected both growth (P<0.05) and mortality parameters (P<0.01). The coefficients for the weight-length relationship. however, were not affected by stocking density. Mortality was highly variable, both during the culture period and between the different stocking densities. Two mortality patterns were identified. One was associated with post-spawning mortality and lower stocking rates. The other occurred at high densities where increased temperatures and overstocking provoked high mortalities and extremely divergent survival responses. The results showed that mortality, rather than growth, reflects more accurately the effects of density, and that better survival is not necessarily produced by stocking at the lowest rate.     

Population ecological parameters and biomass of anchovy kilka <Emphasis Type="Italic">Clupeonella engrauliformis</Emphasis> in the Caspian Sea

ABSTRACT:   Through most of the last century, three endemic kilka species supported major commercial species in the Caspian Sea. It is clear that catches and abundance of all species have changed, but catch and sampling data are limited and stock assessments are inadequate. Recent changes in the Caspian Sea ecosystem have occurred as a consequence of climatic environmental change (sea level change) and ecologic change caused by the invasive ctenophore Mnemiopsis leidyi . This paper examines the effects of these changes on the population biology and biomass of anchovy kilka Clupeonella engrauliformis in Iranian waters of the Caspian Sea from 1995 to 2004. For most years during this 10-year period, we estimated the age structure of catch, length–weight relationship, von Bertalanffy growth parameters, condition factors, sex ratios, maturity stages determined from ovarian analysis, natural and fishing mortality, age at first capture, and spawning biomass. The instantaneous coefficient of natural mortality was estimated as 0.473/year and the instantaneous coefficient of fishing mortality varied during the 10-year period between 0.541 and 2.690/year. Biomass of anchovy kilka declined from about 186 000 t in 1996 to less than 12 000 t in 2004. Recent high fishing rates were not sustainable after the introduction of Mnemiopsis , so overfishing is part of the explanation for the collapse of anchovy kilka in the Caspian Sea.     

底质对小褐虾生长和存活率影响的实验研究

本研究的目的在于通过小褐虾(Crangon uritai)的人工饲养,以观察栖息底质对其存活率和生长的影响。实验小褐虾样本来自韩国釜山Dadaepo(35°02′N,128°57′E)附近4 m水深海域的桁杆拖网渔获,共选取80尾样本进行实验,其中雌性40尾、雄性40尾,并分别被独立饲养在40个有沙和40个无沙的2 L容器中。为便于分析,将实验样本设为每组20尾,分别为无沙饲养的雌性组NSF和雄性组NSM,以及有沙饲养的雌性组SAF和雄性组SAM。实验环境条件为水温14℃、盐度32.5、光周期L∶D为12∶12。饲养期间,每天投喂新鲜的冷冻虾肉,投喂24 h后将残饵虹吸排除,海水每3天更换1次,整个实验持续100 d。实验前测定每尾实验小褐虾样本的体长和性别。实验中每天检查每个容器中的小褐虾蜕皮、死亡和残饵情况,并记录蜕皮时间以便计算其蜕皮间隔。结果表明,在各组最初样本的甲长分布之间没有显著性差异(P>0.05)的情况下,经过整个实验周期,小褐虾NSF和NSM的存活率分别为28%和10%,而SAF和SAM分别为38%和25%。各对照组个体平均甲长的增长量NSF为1.22 mm、SAF为1.43 mm、NSM为0.6 mm、SAM为0.9 mm。有沙饲养条件下,雌性和雄性的蜕皮间隔分别为15.0 d和15.3 d,而无沙饲养的雌雄的蜕皮间隔分别为16.0 d和16.0 d。无论雌性还是雄性在有沙饲养条件的蜕皮间隔均比无沙饲养的短。有沙饲养的雌、雄个体蜕皮增长率分别为5.2%和4.8%,无沙饲养的蜕皮增长率分别为3.7%和3.2%,在有沙饲养条件下雌、雄的蜕皮增长率均较无沙饲养的要大。有沙饲养的雌雄个体生长速度均较无沙饲养的要快,有沙饲养的雌性个体绝对增长率相对于雄性个体要更高。在提供沙质底质的条件下,小褐虾的存活率提高,蜕皮间隔明显缩短,蜕皮增长率增大,更有利于小褐虾的生长。[中国水产科学,2007,14(1):90-98]     

Shell growth and age determination of the brackish water bivalve Corbicula japonica in Lake Shinji, Japan

ABSTRACT:   Shell growth and age determination of Corbicula japonica were investigated from samples collected monthly at two sites and field growth experiments from November 1999 to November 2000 in Lake Shinji. Both specimens did not grow in winter when the water temperature was below 11°C, but grew rapidly from spring to early summer when the water temperature rose from 15°C to 30°C, before further growing slowly from summer to autumn after the main breeding period. The monthly marginal growth distribution of the samples indicated that the concentric groove on the shell surface was an annual growth ring. It is concluded that the age of C .  japonica in the i -ring group when the shell growth resumed in spring was i  + 0.5 ( i  = 1, 2, · · ·), because the first true growth ring was formed at 0–2 mm in shell length, which then faded with growth. Lee's phenomenon was observed in the age determination results, and thus the growth coefficient and the asymptotic shell length of the von Bertalanffy growth equation were not estimated from the samples. However, these parameters were estimated from the annual shell length increments of the experimental individuals, which were 0.331/year and 28.2 mm, respectively.     

基于科学调查与渔业生产数据的山东近海口虾蛄生长参数估算

渔业资源评估一般有两种数据来源,即科学调查数据和渔业生产数据;前者需要定期出海采样,耗时长且费用高,后者易于获取但样本代表性存在问题。本研究以山东近海口虾蛄为例,基于电子体长频率方法(ELEFAN)评估了口虾蛄的生长参数,采用bootstrap重抽样方法比较了基于渔业生产数据与科学调查数据分析结果的差异,旨在探讨渔业生产数据在估算生长参数上的准确性。结果表明,科学调查数据估算得到的口虾蛄von Bertalanffy季节性生长方程中的极限体长L_∞=193.16mm,K=0.62,生产数据估算得到的口虾蛄极限体长L_∞=171.70mm,K=0.67;非参数检验表明基于两种采样方法所求得的口虾蛄的极限体长L_∞呈现显著性差异, K和"夏季点"t_s均呈现不显著性差异。本研究表明,渔业生产数据在一定程度上能够反映生物的生长状况,对K和t_s的估算与科学调查数据估算的结果较为接近,但对极限体长的估算误差较大。因此口虾蛄生长研究需要依靠科学调查数据的支持,同时渔业生产数据可以作为辅助信息。     

Age‐0 blue catfish habitat use and population demographics in the middle Mississippi River

The demographics (e.g. hatch time, growth and mortality) and habitat (macrohabitat and mesohabitat) use of age‐0 blue catfish Ictalurus furcatus (Lesueur) were evaluated in the un‐impounded reach of the middle Mississippi River during 2003–2010. Each year, island complexes and adjacent main river habitats were trawled, and 7,373 age‐0 blue catfish (10–144 mm total length) were collected. Blue catfish hatch timing varied slightly across years and generally began in June and ended in August. Age‐0 blue catfish growth rates and instantaneous mortality rates differed among years. Catch rates of age‐0 blue catfish were highest in side channels and around islands, whereas main channel habitats were infrequently occupied. Regarding mesohabitat use, age‐0 blue catfish frequently occupied low velocity areas (i.e. 0.3–0.4 m/s) of shallow depth (i.e. 1–4 m) and sand substratum. This study has provided insight into age‐0 blue catfish population dynamics and has highlighted the importance of specific habitat characteristics in large rivers that may aid in recruitment of this species.