太湖椭圆萝卜螺的食物来源分析   总被引：3，自引：1，他引：2  

李宽意  刘正文  李传红  李艳敏  文明章 《湖泊科学》2008,20(3):339-343

椭圆萝卜螺（Radix swinhoei）是太湖常见螺类,能牧食附着生物与多种水生植物。对植食性螺类而言,食物的主要来源究竟是水生植物还是附着生物尚存在争议。以来自太湖的苦草、轮叶黑藻、附着生物及混合食物（苦草＋轮叶黑藻＋附着生物）作为椭圆萝卜螺的四组食物,通过两个月的室内养殖实验,根据椭圆萝卜螺的生长指标来分析其主要食物来源。结果表明：以苦草、轮叶黑藻为食物时,椭圆萝卜螺的成活率（成螺）、特定生长率（幼螺与成螺）均显著低于附着生物、混合食物,食物种类对幼螺成活率的影响则不显著。另外,食物种类对幼螺壳长的增长有显著影响,在牧食两种水生植物后,幼螺平均每天壳长增长在0.01-0.02mm之间,而牧食附着生物与混合食物后每天增长0.05mm以上。分析认为,椭圆萝卜螺尽管牧食水生植物,但附着生物仍是其主要的食物来源,并对其原因进行了初步探讨。  相似文献   

太湖不同生态型湖区湖鲚(Coilia ectenes taihuensis)食物组成及其季节变化     

王银平  谷孝鸿  曾庆飞  毛志刚  王文侠  谷先坤  李旭光 《湖泊科学》2016,28(5):1078-1085

利用单船表层单囊拖网于2013年2 12月分别在太湖不同生态型湖区(敞水湖区和草型湖区)采集湖鲚(Coilia ectenes taihuensis)样品,同时用刺网补充大个体样品.通过胃含物鉴定,分析湖鲚饵料生物的种类及数量季节和湖区间差异,同时测定湖鲚摄食率、肥满度和食物选择系数等.结果显示,湖鲚主要食物为浮游枝角类和桡足类,此外,水生昆虫、轮虫和小型鱼虾也是湖鲚的重要食物来源.湖鲚食物组成季节变化明显,冬季以桡足类的哲水蚤(Calanus spp.)、剑水蚤(Cyclops spp.)为主,夏、秋季则以枝角类的象鼻溞(Bosmina spp.)、裸腹溞(Moina spp.)和盘肠溞(Chydorus spp.)为主.不同湖区湖鲚食物种类差异明显,草型湖区水生昆虫、鱼虾较敞水湖区多,桡足类较敞水湖区少.不同湖区间湖鲚食物数量差异明显,敞水湖区湖鲚平均食物数量为788.98±262.4 ind./尾,而草型湖区仅为298.85±71.1 ind./尾.湖鲚主动摄食大型枝角类,如僧帽溞(Daphnia cucullata)、低额溞(Simocephalus spp.)和大型溞(Daphnia magna),选择指数(Ii)介于0.59~1.00之间.小型裸腹溞(Moina spp.)也是湖鲚主动选择的食物(0.62Ii0.95),但湖鲚对桡足类选择性较低,这可能与桡足类较强的逃避能力有关.湖鲚对食物选择性的季节变化明显,如冬季回避透明薄皮溞(Leptodora kindti),而夏季则主动选择,但不同湖区湖鲚对食物的选择差别较小.本研究结果有利于从食物网层面剖析湖鲚种群增长原因,进而通过生物操纵理论对湖鲚种群进行控制,最终为形成合理的湖泊渔业结构和湖泊环境修复提供科学依据.  相似文献   

食物与桡足类营养级对亚热带分层水库浮游动物群落结构的影响     

陈辉煌  王文平  薛媛媛  高肖飞  金磊  杨军 《湖泊科学》2022,34(1):174-183

于2014年10-12月,采集厦门溪东水库浮游动物、浮游植物、浮游细菌与悬浮物样品,分析浮游动物群落与食物质量和食物浓度的关系,探讨桡足类营养级变化对浮游动物的影响.结果 表明,空间上后生浮游动物群落结构在水库不同水层间的差异不显著;时间上桡足类在水华期和非水华期的差异不显著,枝角类和轮虫在水华期和非水华期的差异显著....  相似文献   

持久性卤代有机污染物(PHCs)在食物网中的生物放大研究进展北大核心CSCD     

郑晓波  罗孝俊  麦碧娴 《矿物岩石地球化学通报》2020,(1):30-43

持久性卤代有机污染物(PHCs)具有持久性、生物富集性和毒性,是对生态环境和人类健康有严重威胁的污染物。PHCs浓度会沿食物链在生物中逐营养级放大,对高等生物及人体产生毒性。本文综述了PHCs在食物网中生物放大的特征,总结了国内外对食物网中PHCs的营养级放大因子研究进展,探讨了生态和化学因素对PHCs沿食物链传递过程的影响。目前的研究多集中于水生生态系统中传统PHCs的生物放大,对PHCs的生物差异性代谢缺乏足够的了解,难以说明不同生态系统中复杂的气候、地理、生物种群特征对PHCs生物放大的影响,也给准确评估PHCs的生态风险带来了困难。PHCs的生物放大研究需要引入更多先进地球化学手段和准确构建不同生态系统的野生食物网,阐明PHCs的生物放大机制和影响因素。  相似文献   

哈萨克斯坦食物消费模式及影响因素分析（英文）     

梁一行  甄霖  胡云锋  闫慧敏  张昌顺 《资源与生态学报(英文版)》2020,11(1):121-127

人类对生态系统的过度利用使得维持生态系统服务功能和食物消费需求间的矛盾日益突出。哈萨克斯坦作为全球生态问题最突出的国家之一,人地、草畜矛盾非常严峻。因此,探究哈萨克斯坦食物消费模式及影响因素,进而提高食物消费可持续性、维持生态系统服务功能显得尤为重要。本文以2012年、2016年哈萨克斯坦食物消费数据为基础,通过对消费模式的划分及其变化分析,得到了以下主要结论:受消费习惯、食物供给和社会经济发展影响,哈萨克斯坦存在三种食物消费模式,分别为以奶、谷物消费为主的模式,以奶、谷物和肉类为主的模式,以奶、谷物、肉类、蔬果消费为主的模式,三种消费模式特征差异明显,分别分布在哈萨克斯坦的北、中、南地区;值得注意的是,哈萨克斯坦的食物消费有向以奶、谷物和肉类为主的模式变化的趋势。面对不同的食7品消费模式及其变化趋势,政府可通过转变食物生产观念、加大国内外区域间交流合作来增加当地居民的福祉。  相似文献   

Effects of Calanoid Copepod Schmackeriapoplesia as a Live Food on the Growth,Survival and Fatty Acid Composition of Larvae and Juveniles of Japanese Flounder,Paralichthys olivaceus     

LIU Guangxing  XU Donghui 《青岛海洋大学学报(英文版)》2009,(4):359-365

Zooplankton constitutes a major part of the diet for fish larvae in the marine food web, and it is generally believed that copepods can meet the nutritional requirements of fish larvae. In this study, calanoid copepod Schmackeria poplesia, rotifer Brachionus plicatilis and anostraca crustacean Artemia sp. were analyzed for fatty acid contents, and were used as live food for cul- turing larval Japanese flounder, Paralichthys olivaceus. The total content of three types of HUFAs （DHA, EPA and ARA） in S. po- plesia was significantly higher than that in the other two live foods （P〈O.O1）. Three live organisms were used for raising larvae and juveniles of Paralichthys olivaceus respectively for 15 and 10 d. Then the growth, survival and fatty acid composition of the larvae and juveniles were investigated. The results showed that the larvae and juveniles fed with copepods （S. poplesia） had significantly higher growth rate than those fed with the other two organisms （P〈0.01）. The survival of the flounder larvae fed with copepods was significantly higher than that of the others （P〈0.01）, and the survival of the juvenile fish fed with copepods was higher than that fed with Artemia （P〈0.05）. The contents of three types of HUFAs （DHA, EPA and ARA） and the ratio of DHA/EPA in larval and juve- nile flounder P. olivaceus were analyzed. The results showed that the contents of DHA, EPA and ARA in the larvae and juveniles fed with S. poplesia were higher than those fed with a mixed diet orArtemia only, and the ratio of EPA/ARA in larvae and juveniles of P. olivaceus fed with S. poplesia was lower than that in the case of feeding with a mixed diet or Artemia only. The present data showed that copepod is the best choice for feeding the larvae and juveniles of fish considering its effects on the survival, growth and nutrition composition of the fish.  相似文献   

复印综合     

《青海国土经略》2009,(6):45-45

由于复印机的静电作用、空气中产生臭氧,这种物质使人头痛、头晕、咳嗽等。预防的办法是：复印机要避免日光直射,室内空气要经常流通;经常与复印机打交道的人,要适当增加含维生素E的食物。  相似文献   

Effects of calanoid copepod Schmackeria poplesia as a live food on the growth, survival and fatty acid composition of larvae and juveniles of Japanese flounder, Paralichthys olivaceus     

Guangxing Liu  Donghui Xu 《中国海洋大学学报(英文版)》2009,8(4):359-365

Zooplankton constitutes a major part of the diet for fish larvae in the marine food web, and it is generally believed that copepods can meet the nutritional requirements of fish larvae. In this study, calanoid copepod Schmackeria poplesia, rotifer Brachionus plicatilis and anostraca crustacean Artemia sp. were analyzed for fatty acid contents, and were used as live food for culturing larval Japanese flounder, Paralichthys olivaceus. The total content of three types of HUFAs (DHA, EPA and ARA) in S. poplesia was significantly higher than that in the other two live foods (P<0.01). Three live organisms were used for raising larvae and juveniles of Paralichthys olivaceus respectively for 15 and 10 d. Then the growth, survival and fatty acid composition of the larvae and juveniles were investigated. The results showed that the larvae and juveniles fed with copepods (S. poplesia) had significantly higher growth rate than those fed with the other two organisms (P<0.01). The survival of the flounder larvae fed with copepods was significantly higher than that of the others (P<0.01), and the survival of the juvenile fish fed with copepods was higher than that fed with Artemia (P<0.05). The contents of three types of HUFAs (DHA, EPA and ARA) and the ratio of DHA/EPA in larval and juvenile flounder P. olivaceus were analyzed. The results showed that the contents of DHA, EPA and ARA in the larvae and juveniles fed with S. poplesia were higher than those fed with a mixed diet or Artemia only, and the ratio of EPA/ARA in larvae and juveniles of P. olivaceus fed with S. poplesia was lower than that in the case of feeding with a mixed diet or Artemia only. The present data showed that copepod is the best choice for feeding the larvae and juveniles of fish considering its effects on the survival, growth and nutrition composition of the fish.  相似文献   

牡蛎中诺如病毒的分子流行病学研究进展     

柳淑芳  苏来金  周德庆 《海洋科学》2008,32(8):82-86

牡蛎是重要的海产贝类,其味道鲜美,倍受人们喜爱,许多地区仍有生吃牡蛎的习惯。相关研究结果表明,牡蛎不仅是副溶血性弧菌等病原菌的携带者,也是甲型肝炎、诺如病毒（Noroviruses,NVs）等病毒的主要载体^[1]。NVs是目前习见的食物源性病毒之一^[2],近年来世界范围内相继报道多起食物因污染NVs病毒导致急性胃肠炎的暴发和散发,  相似文献   

国外耕地保护的常用手段     

陈美球 《河南国土资源》2008,(8)

保护耕地是当今世界实现可持续发展战略目标的一个共同关注的热点。纵观世界各国耕地保护的动因,可以归纳为四个方面：一是食物安全。二是耕地为社会提供的公共自然福利功能。除了生产农产品外,耕地还给人类提供各种各样的非生产性功能,如农田耕作传统文化、开放空间、农村独特景观、生物栖息、空气与地下水的净化,这些功能具有强烈的外部性,为社会公众共同享受,且不能通过市场规律调节,人们对这种公共自然福利的需求,  相似文献