中西太平洋镰状真鲨的生物学信息初步研究

镰状真鲨(Carcharhinus falciformis)是金枪鱼(Thunnus)延绳钓渔业中常见的兼捕鱼种之一,位于海洋食物链的顶端,对海洋物种多样性和生态系统的稳定性有重要意义,2017年10月1日作为濒危物种被正式列入濒危野生动植物种国际贸易公约附录Ⅱ中。作者根据中国金枪鱼渔业科学观察员在中西太平洋海域(7°S~9°N,149°E~150°W)采集的1 150尾镰状真鲨样本,对其叉长、体质量、繁殖和摄食等生物学信息进行初步研究与分析。结果表明:雌、雄镰状真鲨的优势叉长范围分别为80~180 cm和60~150 cm,雌性叉长均值显著大于雄性;雌、雄的叉长和体质量关系无显著性差异(ANCOVA,P0.05),叉长和体质量的幂函数关系为:W_R=9×10–6×L_F~(2.9712);雌、雄性比符合1︰1比例;镰状真鲨的鳍脚长度与叉长呈显著正相关性,其线性关系为L_C=0.1492×L_F–6.5;镰状真鲨的怀仔数为4~15尾,平均怀仔数为8尾,子宫内雌雄胚胎长度范围为24~56 cm;摄食等级以空胃率为主,其次为1级,分别为51.77%、35.07%。     

南太平洋所罗门群岛海域黄鳍金枪鱼繁殖生物学研究

根据2012年9~12月所罗门群岛海域采集的353尾黄鳍金枪鱼Thunnus albacares样本,分析渔获物个体组成、性别比例、性成熟率和性腺指数等繁殖生物学参数。结果表明,捕获个体中包含大小两个群体;雌性群体个体规格明显小于雄性(p0.001)。春夏季9~12月雌、雄总体性别比为0.67︰1,显著偏离1︰1(p0.01);但性别比例与调查月份和个体大小密切相关,从9月到12月逐渐接近,至12月达到1︰1(p0.05)。性别比例随叉长增长逐步降低,叉长大于110cm个体中以雄性为主(p0.05),雌性比例与叉长呈现线性负相关关系,相关系数为-0.90,(p0.01)。雌、雄个体性成熟率和性腺指数在春末夏初间逐步增长,至11~12月达到最高;Ⅴ~Ⅵ期产卵个体比例增加,这表明所罗门群岛海域黄鳍金枪鱼春夏季存在产卵群体,从10月开始出现产卵个体,调查期间12月产卵个体比例达到相对最高,并且性腺指数与叉长呈现正相关关系;更一步的分析表明,雌、雄个体初次性成熟叉长分别为97.4cm和103.7cm。对该海域黄鳍金枪鱼繁殖生物学的研究有助于了解该种群资源状况,对渔业资源评估具有重要意义。     

热带中东大西洋海域大青鲨繁殖生物学研究

大青鲨在海洋生态系统中处于重要的地位,研究其繁殖生物学有助于人们更好地理解大青鲨的资源状况。本文根据2007年12月-2008年3月采集的热带中东大西洋海域金枪鱼延绳钓兼捕大青鲨样本,对大青鲨的繁殖生物学特征进行了研究。雌雄大青鲨平均全长分别为248cm和260cm,雄性大青鲨全长分布显著大于雌性大青鲨(P<0.01);获得的雌雄大青鲨都处于性成熟状态,大青鲨成体及胎儿雌雄性比都符合1∶1,雄性大青鲨精巢和总性腺重量均随鱼体全长的增加而增加(P<0.01),而雌性大青鲨卵巢重随鱼体全长变化不大(P>0.05),总性腺重量随鱼体全长的增加而增加(P<0.05);鳍脚长度和雄性大青鲨全长关系线性显著(P<0.01),卵壳腺宽度随雌性大青鲨全长而增加(P<0.05);雌性大青鲨怀胎儿数3～50尾,平均33尾,怀胎儿数随雌性大青鲨全长的略有增加趋势(P=0.39),大青鲨胎儿的平均全长为22.3cm,胎儿的平均体重为61.9g,胎儿全长(TL)与胎儿体重(RW)关系呈对数线性显著(P<0.01),其关系方程为:RW=0.051×TL2.180。结果可为我国参与国际鲨鱼养护与管理,评价热带大西洋公海海域大青鲨种群数量变动提供基础生物学数据。     

热带大西洋公海锯鳞四鳍旗鱼生物学与钓捕深度研究

根据2007年—2010年间两个航次的调查采集的热带大西洋公海海域(05°37′N~14°59′N,29°00′W~40°54′W)金枪鱼延绳钓兼捕的锯鳞四鳍旗鱼(Tetrapturus pfluegeri)渔业和生物学数据,研究了锯鳞四鳍旗鱼的长度组成、各长度之间和长度重量之间关系、性比、性腺成熟度及性腺指数。研究表明,锯鳞四鳍旗鱼的兼捕率为0.06170尾/千钩,雌雄下颌叉长(LJFL)分布不存在显著差异(K-S test,P0.05)。雌雄锯鳞四鳍旗鱼下颌叉长(LJFL)与下颌体长(LJPCL)、下颌全长(LJTL)的关系呈线性显著相关(t-test,P0.01),关系方程分别为:LJPCL=0.9065LJFL+4.5299;LJTL=1.0606LJFL+10.303。锯鳞四鳍旗鱼下颌叉长(LJFL)与体重的关系呈对数线性显著(t-test,P0.01),关系方程为:RW=5.9162×10~(-6) LJFL2.9292。雌雄锯鳞四鳍旗鱼性比为1:1.33,雌性锯鳞四鳍旗鱼性腺成熟度以Ⅴ期占优势,平均性腺指数为1.11;雄性锯鳞四鳍旗鱼性腺成熟度以Ⅰ期占优势,平均性腺指数为0.16。兼捕的锯鳞四鳍旗鱼中有70%是在300m以上水层钓获的。     

北太平洋柔鱼生殖群体结构特征及繁殖生物学

根据2010年6～9月北太平洋柔鱼(Ommastrephe bartramii)渔业的现场调查资料,分析了北太平洋柔鱼胴长和体质量组成结构、性比、初次性成熟胴长、群体成熟度指数等等基础性的渔业生物学参数,阐述了该海域柔鱼的种群结构动态及繁殖生物学的特征.结果表明:各月北太平洋柔鱼生殖群体中雌性个体数量大于雄性,且雌性个体的平均胴长及体质量均显著大于雄性;生殖群体中雌、雄个体胴长与体质量关系的差异极为显著;相同胴长组下雄性个体的性成熟率要高于雌性;北太平洋柔鱼初次性成熟胴长ML0％♀为261.83 mm;Ml50％♂为255.60mm,雄性初次性成熟胴长显著小于雌性;东部海区(170°W～178°W)生殖群体比例及个体大小明显高于两部海区传统作业渔场(150°E～160°E).判断东西部海区柔鱼是否是同一群体,还需要连续性的调查,进一步分析其成熟度随时间的变化及利用耳石信息分析技术来确定,还可以用微卫星技术测定分析以及标志放流法来判定,结论更为准确.     

北太平洋柔鱼生殖群体结构特征及繁殖生物学

根据2010年6～9月北太平洋柔鱼(Ommastrephe bartramii)渔业的现场调查资料,分析了北太平洋柔鱼胴长和体质量组成结构、性比、初次性成熟胴长、群体成熟度指数等等基础性的渔业生物学参数,阐述了该海域柔鱼的种群结构动态及繁殖生物学的特征。结果表明:各月北太平洋柔鱼生殖群体中雌性个体数量大于雄性,且雌性个体的平均胴长及体质量均显著大于雄性;生殖群体中雌、雄个体胴长与体质量关系的差异极为显著;相同胴长组下雄性个体的性成熟率要高于雌性;北太平洋柔鱼初次性成熟胴长ML50%♀为261.83 mm;ML50%♂为255.60 mm,雄性初次性成熟胴长显著小于雌性;东部海区(170°W～178°W)生殖群体比例及个体大小明显高于西部海区传统作业渔场(150°E～160°E)。判断东西部海区柔鱼是否是同一群体,还需要连续性的调查,进一步分析其成熟度随时间的变化及利用耳石信息分析技术来确定,还可以用微卫星技术测定分析以及标志放流法来判定,结论更为准确。     

印度洋东部金枪鱼延绳钓渔业研究--大眼金枪鱼(Thunnus obesus)的生物学特征

根据作者在印度洋东部海域的延绳钓生产实践,对渔获的大眼金枪鱼群体的群体构成、摄食、繁殖等基本生物学特征进行了初步探讨.结果表明,渔获群体由纯重10～115kg、叉长80～195cm个体组成,纯重与叉长关系式w=2.000×10-5×L2.969;渔获物以3～5龄个体为主,雄性个体所占比例明显高于雌性个体,且随年龄增长雄性个体所占比例逐步提高.鱼群在该海域产卵期较长,不同年龄组性腺发育节律有明显差异.     

印度洋中西部大眼金枪鱼资源生物学的初步研究

根据2003~2004年1~6月份印度洋海域金枪鱼延绳钓生产实践及调查,对所捕获的大眼金枪鱼群体的构成、性比和胃含物等基本生物学特征进行了初步探讨及简单比较。结果表明,渔获中大眼金枪鱼体重范围为7~136kg(2003年)及14~100kg(2004年)。2003年,雌性个体所占比例基本上维持在0.45左右;2004年,雌性个体所占比例较2003年大。2003~2004年渔获中大眼金枪鱼分别由叉长69~201cm及55~190cm的个体组成。2003年及2004年各月份1级所占比较均较大,1级以后胃饱满度频次基本上呈下降趋势。3~6月为印度洋中修补大眼金枪鱼的产卵期。体长-体重关系为W=3×10-5L2.8838。     

南海大眼金枪鱼和黄鳍金枪鱼生物学特性及其分布

利用2010年3月—2013年2月南海金枪鱼延绳钓探捕与渔业生产监测取得的生物学数据和生产数据,对南海的大眼金枪鱼(Thunnus obesus)和黄鳍金枪鱼(Thunnus albacres)的生物学特性和渔场分布进行了研究。结果表明:(1)南海大眼金枪鱼叉长范围50—169cm,平均为111.8cm,体重范围2.45—87kg,平均为33.2kg,叉长(FL)体重(W)关系:W=1.74×10–5FL3.01,性腺成熟度Ⅱ期居多,占总尾数的45.27%。绝对怀卵量109.46—456.95万粒,摄食强度以0—2级为主。大眼金枪鱼延绳钓渔场春夏季分布于南沙西北部和南沙中西部海域;秋冬季分布于西、中沙和南沙西北部海域。渔获水深90%集中在150—400m。(2)南海黄鳍金枪鱼叉长范围41—180cm,平均为107.9cm,体重范围1.2—77.5kg,平均为27.9kg,叉长体重关系:W=2.19×10–5FL2.94,性腺成熟度以Ⅱ—Ⅳ期居多,占总尾数的89.01%,绝对怀卵量15—154万粒,摄食强度以1—2级为主。黄鳍金枪鱼延绳钓渔场春夏季分布于南沙西北部和南沙中西部海域;秋冬季分布于西、中沙、南沙西北部、南沙中西部海域。渔获水深93.75%集中在50—350m。西沙西部和南沙西北部海域是灯光围网和灯光罩网捕捞金枪鱼的重要渔场。研究认为:(1)在南海可发展小型冷海水延绳钓船,在每年10月末—次年5月初在西沙东北海域开展浅水延绳钓作业;(2)在南海的岛礁附近设置PAYAO群,开展金枪鱼灯光罩网或围网捕捞。(3)目前取得的资料仍然有限,未来仍需进一步调查,以掌握南海金枪鱼种群动态,为渔业开发和养护提供建议。     

热带中东大西洋海域剑鱼种群特征初步研究

根据2007年12月-2008年3月采集的热带中东大西洋海域(05°37′N~12°01′N,29°00′W~36°51′W)金枪鱼延绳钓捕捞的剑鱼生物学数据,研究了剑鱼的渔获长度组成、各长度之间和长度重量之间关系、雌雄性比、性腺成熟度及性腺指数。研究表明,雌性剑鱼下颌叉长分布显著大于雄性剑鱼(K-S test,t-test,P0.01)。雌雄剑鱼性比为1:0.4,当剑鱼下颌叉长长度大于180cm,雌性剑鱼性比为100%。剑鱼各生物学参数关系雌雄间不存在显著性差异(ANCOVA,P0.05)。剑鱼下颌叉长(LJFL)与下颌体长(LJPCL)、下颌全长(LJTL)关系分别线性显著(t-test,P0.01),方程分别为:LJTL=1.0633LJFL+5.8125;LJPCL=0.8906LJFL-0.7979。剑鱼下颌叉长与体重(RW)、加工后重量(DW)关系分别呈对数线性显著(t-test,P0.01),方程分别为:RW=1.7527×10-6LJFL3.3755;DW=5.4358×10-7LJFL3.5424。体重与加工后重量两者间也呈线性显著(t-test,P‘0.01),方程为:RW=1.3139DW。本次调查雌性剑鱼性腺成熟度以II期占优势,平均性腺指数为0.55,而雄性剑鱼性腺成熟度以I期占优势,平均性腺指数为0.20。该调查海域剑鱼在产卵和肥育之间的过渡期。     

中国海域南褐虾属种类记述(甲壳动物亚门, 十足目, 褐虾科)

为了搞清中国海域存在的南褐虾(Philocheras)的生物多样性和地理分布,作者通过形态学特征系统研究了中国科学院海洋研究所海洋生物标本馆馆藏的南褐虾标本,此标本主要采自中国海域,也检查了部分采自菲律宾海域的标本。本研究和相关文献的结果表明:中国海域存在的南褐虾共计7种,包括作者描绘的4种以及在其他文献中提到的3种。作者对本次研究的4种南褐虾提供了详细的鉴别特征、地理分布、外部整体图和附肢结构图,并对中国海域存在的7种南褐虾提供了检索表。     

Two species of the genusoncaea (copepoda, poecilostomatoida, oncaeidae) from the east sea, Korea

Abstract   Oncaea venusta Philippi, 1843 has been known as having some different size groups, but recent genetic study for cyt b and ITS 1 (Elverset al. 2006) suggests that these size groups can be considered as different species. Of these size groups, the largestO. venusta Philippi and the smallestO. venella Farran, 1929 were first described in Korean waters. The latter is easily distinguishable from the former in the following characteristics in addition to its small size: (1) length to width ratio of genital double somite of two genders smaller, and (2) female second pediger bearing inconspicuous dorso-posterior swelling.Oncaea venusta andO. venella co-occur in Korean waters during spring to fall, but their occurrence patterns seasonally differ: the former shows higher density in fall while the latter does in summer.     

Transitional waters: A new approach, semantics or just muddying the waters?

Estuarine, Coastal and Shelf Science has throughout its history considered a diverse range of habitats including estuaries and fjords, brackish water and lagoons, as well as coastal marine systems. Its articles have reflected recent trends and developments within the estuarine and coastal fields and this includes the changing use of well-accepted terms. The term “transitional waters” first came to prominence in 2000 with the publication of the Water Framework Directive of the European Communities [European Communities, 2000. Directive 2000/60/EC of the European Parliament and of the Council of 23 October 2000 establishing a framework for Community action in the field of water policy. Official Journal of the European Communities 43 (L327), 75 pp.], where “transitional waters” are defined as “bodies of surface water in the vicinity of river mouths which are partially saline in character as a result of their proximity to coastal waters but which are substantially influenced by freshwater flows”. The inclusion of the term transitional waters in our own aims and scope reflects the evolution of language in this subject area, encompassing tidal estuaries and non-tidal brackish water lagoons. This article reflects on some of the difficulties posed by the use of the term and its attempts to be inclusive by incorporating fjords, fjards, river mouths, deltas, rias and lagoons as well as the more classical estuaries. It also discusses the problems of including in the term river mouths discharging either into predominantly brackish areas such as the Baltic Sea, or into freshwater-poor areas bordering the Mediterranean.     

Species composition and dietary relationships in a brackish shallow water fish assemblage in the Bothnian Sea,Sweden

A nearshore fish assemblage inhabiting a shallow bay in the southern Bothnian Sea, Sweden, with demanding environmental conditions (c. 5‰; >15°C during 4 months 1980 and 1 month 1981) was studied during a two-year period, in 1980 and 1981. Seasonal distribution patterns, dietary relationships, and growth rates were studied in Pungitius pungitius (L.), Pomatoschistus minutus (Pallas.), Gasterosteus aculeatus (L.), Phoxinus phoxinus (L.), Pomatoschistus microps (Krøyer) and Gobius niger L. The structure of the juvenile populations changed both over seasons and years but the adult populations remained constant. Lower water temperature, fewer individuals, lower and delayed fish growth, and lower interspecific food overlaps were found in 1981 compared to 1980. Few significant correlations were found in both years between the following community parameters: diversity, niche width, food overlap, and the proportion of each species in the fish assemblage.According to these results it is suggested that food competition and resource partitioning were of minor importance for the structuring of the fish community in the present area. Rather, the extreme salinity and the fluctuations in temperature regulated the fish populations. One may conclude that the populations of juveniles were more influenced by short-term changes in the environment than those of the adults.     

南海表层水中的溶解态Cu,Pb, Zn,Cd

于1998年“南海海洋环境调查”外业工作期间在南海的各个站位,按照严格的防沾污措施采集了106个表层海水样品.采用溶剂萃取-石墨炉原子吸收法对样品中的痕量重金属Cu,Pb,Zn,Cd含量进行了分析测试.测得各重金属的平均值如下:Cu 0.100 μg/dm3,Pb 0.060μg/dm3,Zn 0.086 μg/dm3,Cd 0.007μg/dm3,接近世界大洋水的浓度水平.各重金属的空间分布呈现出海区周边含量高于中央,浓度有自近岸向远海逐渐减小的趋势.相关分析的结果表明各重金属夏季相关性优于冬季,Cu与Cd存在良好的正相关关系,并且首次在南海表层水发现Cu,Cd与营养盐的相关关系.将重金属浓度值作数理统计分析,得到它们在南海的基线值.     

基于Argo浮标和历史资料的热带西太平洋次表层与中层水年代变化分析

利用20世纪80年代和90年代WOD01(World Ocean Database2001)中的CTD温盐剖面资料和2000年以后Argo资料,对比分析了热带西太平洋次表层和中层水团分布的年代变化特征。分析结果表明,在这两个时期,起源于南北太平洋中高纬度海域的各次表层水和中层水,在热带西太平洋分布特征和交织在一起的总体态势基本一致,水团性质的年代变化不大。这与上述两个时段全球海洋-大气耦合系统趋于正常状态相吻合。通过辨识和跟踪表征次表层水性质的盐度极大值,发现南太平洋热带水沿西边界向北扩散程度有所加大,由前一时期的5°N,进一步扩散到6°~7°N;北太平洋热带水在西边界附近的向南扩散程度有所削弱,在2002-2005年间只向南扩散到4°N,而前一个时期则可向南扩散到2°N。通过辨识表征中层水性质的盐度极小值,南极中层水在西边界附近向北扩散程度有所加大,在2002-2005年到达13°N附近,而前一个时期只到达11°N;同期,北太平洋中层水在西边界附近的向南扩散程度有所削弱。上述年代变化与全球水循环强度的变化之间有何关系有待进一步研究。     

Phytoplankton production and adaptation in the vicinity of Pemba and Zanzibar islands,Tanzania

Phytoplankton production and physiology were investigated at six selected locations during a research cruise in early October 2007 in Tanzanian coastal waters. The dataset included photosynthesis– irradiance and active fluorescence parameters, phytoplankton absorption coefficients, and pigment concentrations. Primary production was estimated to vary over the range 0.79–1.89 g C m^?2 d^?1. Diagnostic pigments indicated that micro–nanophytoplankton comprised the communities at three stations and nano–picoplankton at the other three stations. At all stations, the populations maximised their photosynthesis in the upper water column under elevated irradiance and low nutrient conditions. Significant photosynthetic activity was also observed at depth under very low light where the communities increased their quantum yield of photochemistry and the proportion of accessory chlorophylls b and c and photosynthetic carotenoids.     

Dissolved Cu, Pb, Zn and Cd in the South China Sea surface waters

The understanding of the distribution of trace heavy metals in the world ocean has greatlyimProved in the past decades. But most of the data are of vertical profiles of certain stations(Bruland, l980; Paul et al., l992; RObert et al., l990) and large--scale study of temporaland spatial variability of trace heaVy metals in the ocean is rather few. In fact, affected by ver-tical mixing by upwelling or convection, biogenic removal, atmospheric fallout and continentalinput frorn rivers, the dist…     

Biomarker responses to pollution in two invertebrate species: Scrobicularia plana and Nereis diversicolor from the Cádiz bay (SW Spain)

The clam Scrobicularia plana and the polychaete worm Nereis diversicolor were collected in several sites from a littoral enclosure in SW Spain. The aim of our study was to relate various biomarker responses in these species to a pollution gradient caused by untreated domestic discharges and to verify the adequacy of the selected species as sentinels in this habitat. The biomarkers selected were the antioxidant enzymes catalase (CAT), glutathione peroxidase (GPX) and DT-diaphorase (DT-D). In addition, the activities of cytochrome P450-dependent ethoxyresorufin O-deethylase (EROD) activity, the phase II detoxifying enzyme glutathione S-transferase (GST) and the neurotoxicity marker acetylcholinesterase (AChE) were measured. Metallothionein levels were selected as biomarkers of heavy metals exposure in both species. The results suggest a different response in the water filtering organism (clam) and the sediment eater (polychaete), probably as a consequent of different pollution exposure and that samples from the “Caño Sancti-Petri” were exposed to biologically active compounds that altered some of their biochemical responses. AChE was the most sensitive biomarker in both species and N. diversicolor proved to be a more robust sentinel in this ecosystem.