三峡库区澎溪河鱼类时空分布特征的水声学研究

为了解三峡库区支流澎溪河鱼类时空分布变化,2009—2010年的秋季、冬季和春季,使用Simrad EY60鱼探仪对澎溪河的鱼类资源量及其时空分布特征进行3次声学调查。结果表明:3个季节鱼类水平分布不均匀,鱼类最大密度分别为67.07尾/1000 m3,19.66尾/1000m3,17.25尾/1000m3且不同季节上层、中层鱼类密度水平分布有显著性差异(P≤0.01,P=0.03);各季节鱼类密度垂直分布也有一定差异,冬季上层鱼类密度和下层鱼类密度差异较为显著(P=0.05);另外鱼类密度昼夜分布有显著性差异(P<0.05),造成该现象的原因主要是由于鱼类的昼夜垂直节律(Diel Vertical Migration,DVM)引起;3个季节的鱼类目标强度(TS值)的差异极其显著(P<0.01),其中秋季鱼类TS最高((-57.0±5.6)dB),春季TS值最低((-58.6±4.9)dB),造成该差异的原因是4—6月是长江上游鱼类繁殖季节,仔稚鱼居多。鱼类空间分布及其位点的水深关系分析显示,鱼类密度水平分布秋季、冬季与水深不相关(︱r︱<0.2),春季与水深中度负相关(r=-0.5,P≤0.05)。     

长山列岛邻近海域鱼类群落种类组成和多样性时空变化

为了解黄、渤海生态系统交错带长山列岛邻近水域鱼类群落种类组成和多样性,根据2016年10月,2017年1月、5月及8月进行的鱼类资源底拖网调查数据,应用相对重要性指数、物种多样性指数、k优势度曲线等方法,研究了长山列岛邻近海域鱼类群落种类组成、物种多样性时空变化及其与环境因子的关系。结果表明: 该海域共计捕获鱼类77种,以温水性、底层、洄游性鱼类为主,优势种组成季节变化明显,春季、冬季主要优势种为黄鮟鱇,夏季以日本鲭、鳀等中上层鱼类为主。全年共计出现洄游性鱼类46种,季节间物种迁移指数均在100以上,其中秋季物种迁移指数最大。鱼类群落物种丰富度指数在春季最高、Shannon多样性指数和均匀度指数在秋季最高。夏季物种丰富度指数与表层水温呈显著负相关;冬季物种丰富度指数与水深、底层水温呈极显著正相关,Shannon多样性指数与底层水温呈极显著正相关。长山列岛邻近海域作为黄、渤海两大生态系统的交错带,鱼类群落表现出高物种多样性、洄游种多以及明显的时空异质性。     

Differential amplification of antifreeze protein genes in the pleuronectinae

Summary The organization of antifreeze protein (AFP) genes in the yellowtail flounder was investigated by Southern blotting and the characterization of clones from a genomic library. This flounder, like the closely related winter flounder, has a set of 10–12 linked but irregularly spaced AFP genes. However, it lacks the tandemly amplified set of 20 such genes that are present in the winter flounder. DNA sequence analysis of a tandemly repeated gene from winter flounder showed that it can code for one of the two most abundant AFP components in the serum. Consistent with this higher AFP gene dosage, the peak serum AFP level in midwinter was 9 mg/ml in the winter flounder and only 4 mg/ml in the yellowtail flounder. A recent amplification of the AFP gene in the winter flounder lineage might be responsible for the higher serum AFP levels in this fish. This increase in gene dosage might have helped the winter flounder colonize the ice-laden, shallow-water niche that it currently occupies along the east coast of North America. Genomic Southern blotting of two other righteye flounders, the smooth flounder and the American plaice, illustrates another example of a differential amplification of AFP genes that correlates with a species' exposure to ice.     

Comparison of routine oxygen consumption rates of three species of pleuronectids at three temperatures

The oxygen consumption rates of three species of pleuronectids, the yellowtail flounder, Pleuronectes ferrugineus (Storer), the winter flounder, Pleuronectes americanus (Walbaum), and the American plaice, Hippoglossoides platessoides (Fabricius), were examined under simulated, land-based, aquaculture conditions. Routine oxygen consumption (ROC) rates for groups of each species were measured simultaneously using single-pass, flow-through respirometry. This study was conducted over three seasons at temperatures from 2°C to 14°C. An analysis of variance identified a significant interaction between temperature and species on the oxygen consumption rates of these flounder. The analysis indicated that at each temperature, ROC rates were significantly different among the three species (P < 0.05). A subsequent test of each species'ROC rate across the three temperatures indicated that both the yellowtail flounder and the winter flounder had significantly different ROC rates at each temperature experiment (P < 0.05). The ROC of yellowtail and winter flounder responded similarly to changes in experimental temperatures.     

禁渔初期鄱阳湖鱼类时空分布特征

研究于2020—2021年使用Simrad EY60鱼探仪对鄱阳湖进行了秋季、春季和冬季共3次的水声学调查,并同步开展渔获物调查作为补充,分析鄱阳湖鱼类资源时空分布变化特征。结果表明:在季节分布上,鱼类目标强度和密度值都存在显著差异(P<0.05),在目标强度上表现为冬季[(–51.0±14.13) dB]>春季[(–52.10±4.59) dB]>秋季[(–52.71±9.95) dB],在鱼类密度上表现为冬季(54.61 ind./1000 m3)>秋季(46.10 ind./1000 m3)>春季(18.54 ind./1000 m3);在水平分布上,鱼类资源空间分布不均且不同湖区间有显著差异(P<0.05),秋季鱼类主要分布在中部湖区松门山,冬季鱼类主要分布在北部湖区通江水道;在垂直分布上,秋季和冬季均表现为底层>中层>表层,春季表现为表层>中层>底层。综合来看,鄱阳湖鱼类时空分布与鱼类的生活习性如产卵、育肥和越冬等因素密切相关。研究结果为从宏观空间尺度分析区域鱼类时空变动特征提供参考,也为鄱阳湖禁捕效果评估及生物完整...     

大陈岛礁海域甲壳类群落结构时空格局及其环境驱动

为探究局地尺度下近岸岛礁海域之多变水体环境、极高空间异质性对生物群落的影响,于2020—2021年4个季度在大陈岛礁海域底拖网采样,利用等级聚类(cluster)、非度量多维标度(NMDS)等多元统计方法分析甲壳类群落结构的时空格局,并整合温度、盐度、深度等环境因子进行冗余分析(RDA)以解析影响因素,同时利用丰度生物量曲线(ABC)及W统计量评估群落稳态。结果显示：全年共采集甲壳类53种,隶属2目13科29属,虾类占总种类数的56.60%,种类数秋季(43种)>冬季(41种)>春季(31种)>夏季(26种)。优势种的季节更替明显,夏秋季以哈氏仿对虾(Parapenaeopsis hardwickii)、中华管鞭虾(Solenocera crassicornis)和三疣梭子蟹(Portunus trituberculatus)为代表的中大型经济种为主,冬春季则以双斑蟳(Charybdis bimaculata)和细巧仿对虾(Parapenaeopsis tenella)为代表的小个体饵料种为主,口虾蛄(Oratosquilla oratotria)在各个季节皆为优势种...     

Seasonal population dynamics of Neoechinorhynchus qinghaiensis in the carp, Gymnocypris przewalskii przewalskii, from Qinghai Lake, China

Studies on the seasonal population dynamics of Neoechinorhynchus qinghaiensis (Acanthocephala: Neoechinorhynchidae) in its fish host Gymnocypris przewalskii przewalskii in the Qinghai Lake, China, were carried out with samples taken in May 1991, August 1992, November 1992 and February 1993. Prevalences were higher than 44% in all seasons. The mean intensity of infection was above 124 worms per fish. The maximum intensity of worms recovered from a single fish was 1402 in the autumn of 1992. Differences in the mean abundance, mean intensity and prevalence are not statistically significant relative to season and this is likely to be related to the stable temperatures recorded at the bottom of Qinghai Lake. Over-dispersed distributions of N. qinghaiensis in the host population, due to heterogeneity and feeding habits, were observed in all seasons. The size composition of both sexes of N. qinghaiensis showed males to be less than 3.5 mm and females between 0.5 and 4.25 mm, with the main recruitment phase in the worm populations occurring in the autumn, extending through winter and spring with the lowest recruitment occurring in the summer. The maturation and copulation of worms were mainly focused in the summer season. The sex ratio of female to male was both high in winter (1.51:1) and spring (1.48:1). The higher proportion of females and the change in the worm sex ratio in winter can be attributed to the reduced longevity of male worms. As immature male worms exhibit a higher proportion of the worm population than females in all seasons, further studies are needed to determine if such a situation compensates for the shorter life span of males.     

长江口低盐淡水区潮间带鱼类群落结构季节及半月相变化

基于2006年春（5月）、夏（7月）、秋（9月下旬）和冬季（2月）对长江口低盐淡水区水域进行的潮间带鱼类调查结果,分析了鱼类种类及丰度的半月相及其季节变化. 结果表明：长江口低盐淡水区水域潮间带鱼类共有53种;其中鲤科鱼类最多,虾虎鱼科次之,其他科较少. 2顶网具渔获物的鱼类种类和丰度均以春、夏、秋季较高,冬季最低.各个季节的平均种类数和平均丰度均为小潮期小于大潮期. Shannon-Weaver指数（H′）在一个潮周期内的波动幅度较大,且小潮期H′值略低于大潮期. 对鱼类种类丰度进行聚类分析发现,冬季鱼类聚成一组,春、夏和秋季聚成一组. 从整年的情况来看,潮间带鱼类的丰度变化与水温的相关性最高;与潮高的相关性次之;而与盐度的相关性最小.     

黄海中南部细纹狮子鱼的生物学特征及资源分布的季节变化

根据2009年7—8月、10月和2010年1月、5月黄海中南部渔业生物底拖网调查数据,对该海域细纹狮子鱼的生物学特征及其分布的季节变化作了分析。结果表明,细纹狮子鱼平均体长和平均体重从春季(4.7 cm、3.3 g)到冬季(34.2 cm、764.9 g)呈显著增加,并且雄性个体平均体长显著大于雌性个体(P<0.05,春季除外)。性比(♀∶♂)随体长组和季节变化,体长越大趋向于雄性,反之趋向于雌性;夏季雄鱼居多(0.70∶1,P<0.05),秋季则为雌鱼居多(1.35∶1,P<0.05),而冬季(产卵群体)和春季性比接近于1∶1。细纹狮子鱼各季节摄食等级均在2.5以上,冬季雄性个体摄食等级显著大于雌性个体(P<0.05),但雄性个体肥满度为全年最低(1.52)。细纹狮子鱼相对资源量和贡献率从春季(0.17 kg/h,1.54%)到秋季(15.36 kg/h,33.05%)呈上升状态,而冬季(2.37 kg/h,5.60%)有所下降。相比2000年,夏秋季相对渔获量和贡献率提高明显。全年集中分布于7.8—13.6℃,3.20%—3.38%的水域,平均体重和水深有显著的相关性(秋季除外)。另外,根据性成熟个体分布区和稚幼鱼分布的相关历史资料分析发现,除海州湾外,黄海中部深水区可能是细纹狮子鱼的产卵场。     

Context‐specific influence of water temperature on brook trout growth rates in the field

1. Modelling the effects of climate change on freshwater fishes requires robust field‐based estimates accounting for interactions among multiple factors. 2. We used data from an 8‐year individual‐based study of a wild brook trout (Salvelinus fontinalis) population to test the influence of water temperature on season‐specific growth in the context of variation in other environmental (i.e. season, stream flow) or biotic factors (local brook trout biomass density and fish age and size) in West Brook, a third‐order stream in western Massachusetts, U.S.A. 3. Changes in ambient temperature influenced individual growth rates. In general, higher temperatures were associated with higher growth rates in winter and spring and lower growth rates in summer and autumn. However, the effect of temperature on growth was strongly context‐dependent, differing in both magnitude and direction as a function of season, stream flow and fish biomass density. 4. We found that stream flow and temperature had strong and complex interactive effects on trout growth. At the coldest temperatures (in winter), high stream flows were associated with reduced trout growth rates. During spring and autumn and in typical summers (when water temperatures were close to growth optima), higher flows were associated with increased growth rates. In addition, the effect of flow at a given temperature (the flow‐temperature interaction) differed among seasons. 5. Trout density negatively affected growth rate and had strong interactions with temperature in two of four seasons (i.e. spring and summer) with greater negative effects at high temperatures. 6. Our study provided robust, integrative field‐based estimates of the effects of temperature on growth rates for a species which serves as a model organism for cold‐water adapted ectotherms facing the consequences of environmental change. Results of the study strongly suggest that failure to derive season‐specific estimates, or to explicitly consider interactions with flow regime and fish density, will seriously compromise our ability to predict the effects of climate change on stream fish growth rates. Further, the concordance we found between empirical observations and likely energetic mechanisms suggests that our general results should be relevant at broader spatial and temporal scales.     

The diet of blue whiting, hake, horse mackerel and mackerel off Portugal

This paper deals with the diets of blue whiting Micromesistius poutassou (Risso 1810), hake Merluccius merluccius (L. 1758), horse mackerel Trachurus trachurus (L. 1758), and mackerel Scomber scombrus (L. 1758) off Portugal and explores variations in fish length, water depth, latitude and season. All four species feed on fish; however, hake and mackerel are the first and second most important predators, respectively, blue whiting being the most important fish prey for both species. The diets of blue whiting and horse mackerel are composed mainly of crustaceans. Diet variations according to predator fish size are more important than either latitude or depth. In the diets of blue whiting, hake and horse mackerel, prey importance increases with predator size. For blue whiting and horse mackerel, diet variations with fish length and water depth are correlated: small fish are closely associated with coastal areas where they feed on copepods and decapod larvae. Seasonality in the diet is apparent for blue whiting, hake and mackerel. For blue whiting, the decapod Pasiphaea sivado is the most important prey in summer and autumn, being replaced by the euphausid Meganyctiphanes norvegica in winter. In the diet of hake, seasonality was characterised by the major importance of Macroramphosus scolopax in autumn, whereas the diet of mackerel consisted of zooplankton in summer, fish and decapods in autumn and decapod larvae in winter. Seasonal changes in the diet of horse mackerel correspond to a higher diversity of prey in autumn compared to other seasons (although euphausids are the main prey in all seasons). Seasonality in feeding activity is not as marked for the other species as it is for horse mackerel; the percentage of empty stomachs of horse mackerel is greatest in winter, when spawning takes place at the Portuguese coast.     

Seasonal variation in haematological parameters in male and female Tinca tinca

This study was designed to investigate any seasonal (spring, summer, autumn and winter) changes in haematological parameters in the blood of Tinca tinca measuring the number of red blood cells (RBC), haematocrit, white blood cells, and total plasma proteins.The results show significant changes in RBC and haematocrit in males comparing spring and summer with autumn and winter, whereas in females the RBC remained constant for all 4 seasons but the haematocrit decreased in autumn and winter compared to spring and summer. The white blood cells of male and female animals were significantly lower in spring and winter compared to summer and autumn. In male fish total protein contents significantly decreased in autumn and winter compared to spring and summer, whereas in females protein output significantly decreased in winter compared to the other seasons. The results indicate marked seasonal variation in the blood of male and female Tinca tinca. This variation may play a important protective role for the survival of the animals.     

东海太平洋褶柔鱼生殖群体的空间分布及其与环境因子的关系

依据1997-2000年在东海(26°00′-33°00′N、120°30′-128°00′E)进行的4个季节的底拖网调查资料,分析了该海区太平洋褶柔鱼生殖群体的时空分布特征,同时结合广义相加模型(GAM),量化分析了各环境因子对于其种群成熟度指数(PMI)空间分布的影响机制。结果表明:太平洋褶柔鱼生殖群体春、夏、秋、冬4个季节在东海均有分布;秋季PMI值最高,春季最低;4个季节太平洋褶柔鱼生殖群体的分布范围均较广,主要集中在东海外海受台湾暖流和黑潮控制的水域。太平洋褶柔鱼生殖群体的环境适应性存在明显的季节差异:其分布的底温范围为:春季14.70-18.30℃、夏季13.18-20.91℃、秋季13.96-24.67℃、冬季14.33-19.75℃。底盐范围为:春季29.52-34.63、夏季31.57-34.27、秋季32.26-34.72、冬季34.25-34.70。水深范围为:春季55-179m,夏季43-176m、秋季40-184m、冬季79-152m。综上所述,东海太平洋褶柔鱼生殖群体的时空分布具有广范围、多季度的特点,这种分布特征可有效降低其幼体间的种间竞争,为确保其种群繁衍提供有利保障。     

基于稳定同位素方法的闽江口常见鱼类群落营养结构的季节性变化

为了解闽江口常见鱼类群落的营养结构特征,于2015年冬季(1月)、春季(5月)、夏季(8月)、秋季(11月)采集闽江口底拖网渔业资源样品,利用稳定同位素分析闽江口常见鱼类群落营养结构特征及其季节性变化,并计算了基于δ¹³C-δ¹⁵N量化的7个营养结构的群落范围指标.结果表明: 闽江口常见鱼类群落除夏季和秋季的δ¹³C值之间不存在显著性差异,其余各季节之间δ¹³C值均差异显著;δ¹⁵N值春季与其余3个季节都表现出显著性差异,而其余3个季节δ¹⁵N值互相之间均无显著性差异.稳定同位素的量化指标表明: 闽江口常见鱼类群落的营养结构存在季节差异,春季的生态位总空间(TA)、核心生态位空间(SEAc)、鱼类基础食物来源(CR)、营养长度(NR)、鱼类营养多样性(CD)均为四季的最大值;从夏季至秋季再到冬季,生态位总空间(TA)、核心生态位空间(SEAc)、鱼类基础食物来源(CR)、营养长度(NR)、鱼类营养多样性(CD)和营养位置差异(MNND)均逐步上升.闽江口常见鱼类群落营养结构的季节差异可能与鱼类生殖洄游和群落内食源多样性的变化密切相关.     

大亚湾大辣甲水域溶解无机碳垂直分布特征及季节动态

于2007年10月～2008年9月进行了4个季节的垂直采样监测,对大亚湾大辣甲水域溶解无机碳(DIC)的垂向分布和季节动态特征进行了研究,分析了大亚湾溶解无机碳与各环境要素(pH、水温、溶解氧和叶绿素a等)的相关性。结果表明:在春、秋和冬季,大亚湾大辣甲水域DIC含量在垂直分布上差异较小,但夏季(2008年7月)变化较为显著,DIC含量的变化范围为16.79～26.52mg·L^-1;DIC高值基本集中在中、底层水域(8～16m),尤以底层水域(13～16m)为甚;DIC含量基本呈现出春、夏季较高,秋、冬季较低的分布趋势;DIC含量与pH值和水温含量显示出了负相关关系,而与盐度呈正相关关系。     

广西英罗港红树林潮沟鱼类多样性季节动态研究

于1999年分4个季节来采用拦网的方法对广西英罗港红树林潮沟水中鱼类的多样性进行了研究,共发现鱼类54种,隶属于29种44属,季度出现频数F=1～4的鱼类种数分别为27、8、11和8种,各季的优势种明显,但不同季节最大优势种不同,分别为：春季、斑Ji（Clupanodon punctatus);夏季,前鳞骨鲻（Osteomugil ophuyseni）;秋季,眶棘双边鱼（Ambassis gymnocephalus）;冬季,鹿斑Fu（Leiognathus ruconius）,这些鱼类以暖水性种占绝对优势,在生态类型上以底层种类较多,各季节出现鱼类种数分别为：春季30种、夏季30种,秋季26种,冬种22种,夏季与秋季共有种最多,有20个种,这两季节间的相似性指数也最大,达55.6%,多样性指数D、H′、J值均以秋季最高,相对于林外水域,红树林潮沟鱼类群落的鱼类种数及3个指数均较高,跟热带红树林区相比,广西英罗港红树林潮沟鱼类群落的多样性低。     

浙江披山海域主要鱼类时空生态位

依据2015年11月(秋)、2016年2月(冬)、5月(春)、8月(夏)4个航次的渔业资源底拖网调查数据,运用相对重要性指数(IRI)、Shannon指数和Pianka指数对浙江披山海域主要鱼类的时空生态位宽度和重叠进行分析,并结合冗余分析和种间竞争系数研究了主要鱼类间的竞争共存关系及生态位分化.结果 表明:研究期间共...     

Shallow water predation risk for a juvenile flatfish (winter flounder; Pseudopleuronectes americanus, Walbaum) in a northwest Atlantic estuary

Many small fish, including several juvenile Atlantic flatfish, are most abundant in shallow areas presumable because these habitats enhance survivorship and/or growth. In this study, we investigated size-dependent depth distributions and the role of shallow habitats as predator refuges for age-0 winter flounder (Pseudopleuronectes americanus) in a northwest Atlantic estuarine nursery. Analysis of trawl surveys performed during the larval settlement period throughout the Navesink River and Sandy Hook Bay, New Jersey, showed that as fish increased in size, depth of occurrence gradually decreased, so that individuals >35 mm standard length (SL) were concentrated in habitats ∼1 m deep. Tethering in structurally simple and adjacent shallow and deep habitats showed that predation risk for flounder (30-50 mm SL) was low in shallow water (<1 m) and increased rapidly with depth. Summer flounder (Paralychthys dentatus), which were more abundant in trammel nets in deep habitats and included winter flounder in their diets, appeared to be important consumers of tethered fish. Our results indicate that following larval settlement, winter flounder emigrate from or suffer high mortality in deeper water to become concentrated in shallow habitats that can serve as predator refuges even when they lack complex physical structures. These results highlight the potential for functional habitat loss when natural and/or anthropogenic factors make shallow habitats unavailable to young fish.     

Monitoring of microbial populations and their cellulolytic activities during the composting of municipal solid wastes

Seasonal changes in microbial populations and the activities of cellulolytic enzymes were investigated during the composting of municipal solid wastes at Damietta compost plant, Egypt. The changes in temperature, pH and carbon/nitrogen (C/N) ratio were also monitored. The results obtained showed that the temperatures of the windrows in all seasons reached the maximum after 3 weeks of composting and then decreased by the end of the composting period (35 days), but did not reach ambient temperature. Marked changes in pH values of the composts in all seasons were found, but generally, the pH was near neutrality. Significant increases in the size of the microbial populations were obtained in autumn and spring seasons compared to summer and winter seasons. The activities of cellulases were also higher in the autumn and spring seasons than in the summer and winter seasons. The decrease in C/N ratio in autumn and spring was higher than in summer and winter. It was evident that the degradation of organic matter increased by an increase in the microflora and its cellulolytic activities.     

广东沿岸海域鱼类群落排序

根据广东沿岸海域春秋两季底拖网鱼类采样数据,运用多维尺度转换分别对两季的鱼类样品进行排序。排序揭示出的鱼类群落格局及其季度差异与环境变异性密切相关。同处混合水区域的站位鱼类组成较为相似;分布在珠江冲淡水和外海高盐水区域的站位,鱼类组成则与多数沿岸站位有明显差异。春季沿岸海域鱼类组成有一东北－西南向的变化趋势,这一群落格局是由于该海域东北部受低温东海沿岸流影响所致;秋季珠江河口区受冲淡水的影响,而调