烟台第一海水浴场沙源匮乏型海滩地貌和表层沉积物粒度特征     

解燕  ;王张华  ;金秉福 《山东地质》2008,(5):37-40

在烟台第一海水浴场,利用经纬仪进行2条海滩横剖面形态测量,并在不同地貌单元采集沉积物样品进行粒度分析。测量显示,该海滩仅有小规模沙坝和沟槽体系。后滨上有风成沉积,但滩肩和海岸沙丘发育均不明显。粒度分析结果表明,海滩沉积物以中砂、粗砂为主,杂以砾或细砂,比山东半岛其他海滩沉积物明显要粗。由陆向海沉积物呈带状分布,平均高潮线附近和沙坝迎水坡侵蚀作用均显著。因此认为缺乏沙源供应的基岩岬湾式海岸是导致沙滩地貌发育不典型、海滩侵蚀作用显著的主要原因。  相似文献   

Influence of tidal regime,diurnal phase,habitat and season on feeding of an intertidal crab     

Claudia Bas  Juan P. Lancia  Tomás Luppi  Agustina Méndez‐Casariego  Marcelo Kittlein  Eduardo Spivak 《Marine Ecology》2014,35(3):319-331

The relationship between diet and feeding activity of intertidal crabs, and environmental cycles (tidal, daily and seasonal), habitat and level of the intertidal zone (high/low) was studied using Neohelice granulata (Brachyura, Varunidae) as a model. This is a semi‐terrestrial burrowing crab occupying different habitats in the Southwestern Atlantic coasts and estuaries from bare low intertidal mudflats to high intertidal salt marshes, and from fine, organic matter rich sediment to very coarse sediment with low content of organic matter. The study was carried out in two contrasting habitats of three sites with diverse sets of physical and biological conditions. Diet and feeding of adult N. granulata were indirectly studied through the proportion of food items and the presence/absence of food in crab stomachs, respectively. This species has a dual mode of feeding: predominantly herbivorous (live plants or plant litter in salt marshes) or deposit feeder (superficial sediment and detritus in mudflats), but the quantity and quality of ingested food varies among habitats and sites. A trend to omnivory (including algae and conspecifics) was detected in relation to low quality of resources. Feeding activity modulated by a complex interaction of factors varied according to spatial and/or temporal changes in some natural cycles. Males and non‐ovigerous females fed preferably after dark and during submersion periods, but also after emersion periods if mudflat sediment remained wet; salt marsh crab feeding is somewhat independent of light and tidal cycles. Ovigerous females almost never fed. Both diet and feeding activity of this crab seem to be flexible traits adapted to different combinations of physical and biological factors.  相似文献   

三疣梭子蟹(Portunus trituberculatus)的保活参数优化及其代谢响应     

曾廷兰  陈燕  母昌考  王春琳  史策  叶央芳 《海洋与湖沼》2022,53(5):1197-1207

为延长三疣梭子蟹(Portunus trituberculatus)在捕捞后的存活时间,在优化保活温度和充氧量的基础上,再采用基于核磁共振(NMR)的代谢组学技术,比较分析了三疣梭子蟹前鳃代谢谱在充氧和不充氧保活过程中的变化。结果发现, 12 ℃下的三疣梭子蟹存活率最高, 80%的三疣梭子蟹能存活3.5 d。加大充氧量能提高三疣梭子蟹的存活率, 3.6 L氧气可满足一只三疣梭子蟹成蟹存活到3 d以上。因此,保活三疣梭子蟹的适宜温度和充氧量分别是12 ℃和3.6 L。不充氧保活会导致三疣梭子蟹前鳃中乳酸、丙氨酸和葡萄糖等代谢物的快速积累,但充氧保活可抑制这些代谢物的变化,表明氧气通过缓解三疣梭子蟹前鳃的缺氧和渗透压失衡,从而有效延长三疣梭子蟹的存活时间。研究结果为三疣梭子蟹的保活运输提供可借鉴的方法和理论参考。  相似文献   

食物资源不足条件下螯足数量对三疣梭子蟹(Portunus trituberculatus)摄食行为和种内竞食能力的影响   总被引：1，自引：1，他引：0  

何杰  王绪杰  余方平  许文军  谢建军  王庚申  汪玮  施慧 《海洋与湖沼》2017,48(3):609-616

鉴于池塘养殖条件下三疣梭子蟹(Portunus trituberculatus)种内相残现象严重,螯足缺失率较高之实际。本研究对三疣梭子蟹的螯足进行了缺失处理,设置了无螯组(C0)、1螯足组(C1)和2螯足组(C2),在实验室内食物资源不足条件下,探讨了螯足数量(螯足缺失)对三疣梭子蟹摄食行为和竞食能力的影响。结果表明:(1)螯足数量对三疣梭子蟹的索食时间无显著影响(P0.05);(2)缺失螯足(C1,C2组)的三疣梭子蟹均可正常摄食,其中C0组蟹可用第一步足代替螯足抱持食物,将食物送入口中,表现出明显的行为补偿策略,但其啃食速度较慢,啃食耗时是C2组蟹的2倍;(3)C0、C1、C2组三疣梭子蟹均有部分个体同时抢占2份食物,其比率与个体具有的螯足数量有关,螯足越多,同时抢占2份食物的比率越高,其中C2组中有20%个体同时抢占了2份食物,而C0组仅有3%个体同时抢占了2份食物;(4)从螯足数量不同的三疣梭子蟹遭同类抢食的次数、比率来看,螯足数量越多的三疣梭子蟹,抢食欲望、抢食能力越强,而且更趋向向双螯均缺失个体发起抢夺性攻击,表现出明显的"强欺弱"现象;(5)螯足缺失直接影响了三疣梭子蟹对食物的保护,其中C0组中50%个体持有的食物可被同类抢走。整体上,缺失单个螯足对三疣梭子蟹摄食和竞食行为的影响不大,而缺失双螯将严重影响了三疣梭子蟹的摄食和竞食能力。  相似文献   

Spatio‐temporal variation in biomass of the deep‐sea red crab Chaceon affinis in Gran Canaria Island (Canary Islands,Eastern‐Central Atlantic)          下载免费PDF全文

Raül Triay‐Portella  José G. Pajuelo  José A. González 《Marine Ecology》2017,38(5)

The spatial and temporal biomass distribution of Chaceon affinis and its vulnerability to fishing activity in Gran Canaria (Canary Islands) were investigated. The first goal was to assess the influence of the slope steepness and substrate on the size of crab patches, size of the crabs, and crab biomass. The second goal was to evaluate spatial and temporal variation in the biomass over a 15‐month period. The last goal was to assess the influence of fishing activity upon the reduction in the biomass over the same 15‐month period. Only two or three locations in the sampling area generated high‐biomass contour patches. When these patches were superimposed on the isobath lines, they were coincident with the main depth range described for the species in the area. The map of the biomass values clearly showed three structures with cores of the highest biomass in both muddy and rocky‐muddy areas. The biomass was higher on muddy than on rocky‐muddy bottoms. Biomass was twice as high when steepness was reduced to one third between isobaths of 500 and 900 m. The size of crab patches increases linearly with the decrease in slope steepness. The spatial structure of crabs remained fairly stable over time, showing that biomass changes with depth over time. Maps of the estimated biomass values over the 15‐month period showed the same two main patches over time with the cores of highest biomass separated by a distance of between 4.2 and 4.5 km. Although the bathymetric distribution by sexes showed temporal changes, with a displacement to deeper areas made by both sexes over the studied period, only a partial temporal segregation between males and females was observed. During the study period, crabs underwent a significant decline in biomass and this was consistent with the combined catches of both commercial and experimental fishing in the area. Due to its low mobility, C. affinis is highly vulnerable to local depletion by intensive fishing efforts.  相似文献   

三疣梭子蟹CYP4C基因的cDNA克隆及表达分析     

张晓燕  李健  刘萍  陈萍  孙铭 《海洋与湖沼》2014,45(1):73-80

采用RT-PCR及Smart-TM Race技术,首次获得三疣梭子蟹CYP4C基因cDNA全长序列。该基因全长1888bp,编码一个由514个氨基酸组成的多肽,预测分子量大小为59.54kDa,理论等电点为8.08。氨基酸序列中含有CYP基因家族特有的K螺旋保守序列（ExxR）和血红素结合区（FxxGxxxCxG）。同源性及系统进化分析表明,三疣梭子蟹CYP4C基因与岸蟹、凡纳滨对虾、日本沼虾、中国对虾、沟虾、红螯螯虾的同源性分别为88%、72%、66%、59%、60%、59%。荧光定量RT-PCR结果表明,CYP4C在肝胰腺、肌肉、眼柄、鳃和心脏中均有分布,在肝胰腺中表达量最高。高盐（45）胁迫后,三疣梭子蟹CYP4C的表达量显著高于对照组,随着胁迫时间的延长出现逐渐降低的趋势,在胁迫48h后表达量达到对照组水平;低盐（11）胁迫条件下,CYP4C的表达水平随着胁迫时间的延长呈现逐渐下降的趋势,且从胁迫6h开始显著低于对照组。研究推测,CYP4C基因参与三疣梭子蟹盐度适应调节,是蜕皮机制的调控因子之一。  相似文献   

曼氏无针乌贼(Sepiella japonica)繁殖期行为谱特征的研究          下载免费PDF全文

陈佳怡  龙进霞  徐汉祥  张涛  史会来  徐开达  梁君 《海洋与湖沼》2021,52(6):1549-1556

自然海域中曼氏无针乌贼产卵亲体性成熟提前和小型化现象明显，这可能是一种适应性进化，人工干预背景下曼氏无针乌贼繁殖期行为的动态变化值得关注。2020年4-6月室内采用聚焦个体扫描法和定点连续记录法分别观察和记录了曼氏无针乌贼繁殖期的行为活动，并按其生活习性和行为的生物学功能等进行系统化分类，构建了繁殖期行为谱。结果表明，曼氏无针乌贼繁殖期行为谱主要包括三大类12种行为：（1）游泳行为主要分为前进和后退，繁殖期的雌性多处于静潜水底或静浮水中的状态；（2）捕食行为主要分为发现、定位、捕捉和咀嚼等系列动作，曼氏无针乌贼能够快速感知周围17.0-36.0 cm范围内的饵料，捕捉的有效距离为8.0-22.0 cm，能在2.0-10.0 s内完成对饵料的高效捕获；（3）繁殖行为复杂，主要分为求偶、伴游、交配、产卵等，其中求偶行为体现在雄性对雌性的自我展示、追逐配对和争斗护卫等过程，雄性在争斗护卫和伴游过程中的护雌行为尤为激烈。曼氏无针乌贼交配时采用"头对头"的方式，平均交配持续时间42.9 s。曼氏无针乌贼对产卵附着基有选择性且偏好于最初的附卵物，卵群对雌性产卵行为有诱导和刺激作用，每次产卵到附卵过程平均用时108.6 s。曼氏无针乌贼繁殖期行为谱特征的研究可为后续曼氏无针乌贼行为机制和基于全生活史的资源保护等方面提供理论依据。  相似文献   

基于沉积物eDNA评估三疣梭子蟹资源量的方法初探          下载免费PDF全文

张凡瑶  张再美  陈萌琦  韦东升  徐严欢  姚冰  孙振宁  李慧  杨艳艳  周兴  李凡  陈翠霞 《海洋科学》2023,47(5):113-120

本文旨在通过沉积物eDNA (environmental DNA)的分析,建立一种快速评估三疣梭子蟹资源量的方法。采用柱状采泥器对莱州湾同一地点(37°30″E、119°20″N)不同深度(0~24 cm,7个深度)进行样品采集,提取不同深度地层沉积物中的eDNA,并以此为模板,运用三疣梭子蟹COI基因通用型引物和特异性引物分别进行普通PCR和实时荧光定量PCR (quantitative PCR,qPCR)扩增,评估莱州湾近年来三疣梭子蟹的资源量变化。结果显示:7个样品的eDNA中均能扩增出700 bp长度的DNA产物,表明在不同深度沉积物所代表的年份均有三疣梭子蟹的存在;通过Clustal X与MEGA 7.0软件比对各序列碱基之间的差异性,发现不同柱深沉积物中的COI基因共出现11个变化位点,包括8个转换位点、2个颠换位点和1个插入位点;qPCR结果显示,8~9 cm处的三疣梭子蟹COI基因拷贝数要大于其他深度地层沉积物,说明此柱深代表的年份中三疣梭子蟹的资源量高于其他年份。利用沉积物eDNA评估莱州湾海域内的三疣梭子蟹资源量的方法,可以打破时间和空间的限制,检测不同年份三疣梭子蟹的资源量的变化。  相似文献