绢丝丽蚌软体部形态初步观察

绢丝丽蚌Ｌａｍｐｒｏｔｕｌａｆｉｂｒｏｓａ壳厚质优,是制造珠核的极好材料。关于其贝壳形态、地理分布和经济意义,刘月英等作了简要记载［１,２］,而对其软体部形态的观察,迄今未见报道。我们对此进行了初步观察,旨在为绢丝丽蚌资源的合理开发及人工增养殖提供资...     

绢丝丽蚌的配子发生

绢丝丽蚌的配子发生ＧＡＭＥＴＯＧＥＮＥＳＩＳＯＦＬＡＭＰＲＯＴＵＬＡＦＩＢＲＯＳＡ龚世园朱子义张训蒲王明学杨学芬华中农业大学水产学院,武汉４３００７０）ＧＯＮＧＳｈｉＹｕａｎ,ＺＨＵＺｉＹｉ,ＺＨＡＮＧＸｕｎＰｕ,ＷＡＮＧＭｉｎｇＸｕｅ,ＹＡ...     

1龄绢丝丽蚌网箱培育初步试验

初步研究了网箱培育1龄绢丝丽蚌幼蚌的可行性和养殖技术,分析了不同水层、不同密度条件下绢丝丽蚌幼蚌的生长状况。结果表明,1龄绢丝丽蚌网箱培育的适宜密度为2 000 ind/m2,表层吊养优于底养,网箱培育幼蚌的水温宜在18℃以上。     

绢丝丽蚌血细胞类型的研究

依据是否有伪足、细胞质中有无颗粒和细胞大小对绢丝丽蚌血细胞进行了分类.结果表明:绢丝丽蚌血细胞分为无颗粒细胞、颗粒细胞、透明细胞和类淋巴细胞4种类型,各有不同结构,并协同行使机体的运输、防御和免疫功能.     

论丽蚌资源的保护与增殖

丽蚌壳是加工珍珠核的原材料，本文分析了丽蚌资源急剧衰退的原因，介绍了我国丽蚌资源的现状，并就丽蚌的资源保护和资源增殖进行了探讨。     

背瘤丽蚌钩介幼虫寄生变态发育和有效积温的研究

选用黄颡鱼(Pelteobagrus fulvidraco)作为寄主鱼,研究了背瘤丽蚌(Lamprotula leai)钩介幼虫寄生变态发育的过程、生物学零度和有效积温等重要生物学特征。结果显示,背瘤丽蚌钩介幼虫在黄颡鱼的鳃丝、鳍条或须上均能完成变态发育。在水温(25±1)℃时,寄生期为8 d。钩介幼虫腹缘先与寄主鱼体表组织接触,寄生后5 h,大部分被鱼体组织包裹;第2天,内幼虫足丝消失,钩介幼虫全部被包在包囊中;随着钩介幼虫寄生变态发育的进行,其壳颜色逐渐加深;第7天,变成黑色不透明,并有少量钩介幼虫变态为稚蚌;第8天,稚蚌脱落达到高峰期;第9天,稚蚌全部脱落。在寄生阶段,钩介幼虫壳长、壳高和铰合部长未发生显著变化。钩介幼虫寄生变态发育的生物学零度为12.8℃,有效积温为100.2℃.d。     

淡水珍珠养殖技术（五）——蚌病的防治技术

随着养蚌业的发展，生产规模的不断扩大，伴之而来的蚌病日益严重，危害极大。尤其是蚌瘟病，发病传播迅速，能在很短的时间内，使三角帆蚌死亡率高达６５％～９０％，甚至全部死亡，无一幸存。它能给养蚌育珠造成毁灭性打击，使珠农遭受惨重的经济损失。因此一定要加强对蚌的病害防治，不可麻痹大意。１蚌病的预防蚌病的预防应贯彻“以防为主，治疗为辅”的方针，采取无病先防，有病早治，防患于未然的积极方法。预防的措施主要有以下几点。１．１改善生态环境所有蚌病都与生态环境有关，水环境的好坏直接决定着育珠蚌能否健康、快速地生长…     

浅谈鳄鱼养殖

1开展鳄鱼养殖的意义 1.1生物学意义 　　鳄鱼为世界珍稀动物,具有 2亿多年生命史,与恐龙是近亲。其生理功能奇特,生命力顽强, 6500万年前恐龙灭绝,而鳄鱼却生存下来,并繁衍进化至今。鳄鱼体内有一种能够优化核酸的物质,这种物质使核酸充满活力,抗病能力加强,同时激活体内的触酶和 SOD,有效地清除体内垃圾,从而延缓生命衰老,使之寿命超过龟鳖,平均高达 150岁。鳄鱼肌肉内的血红蛋白氨基酸链有着非常奇特的构造,使鳄鱼的血红蛋白携氧量超过其他动物 100倍以上,所以鳄鱼虽用肺呼吸,但在水中闭气本领比鲸、海豚高明得多。因…     

尖刀蛏自然海区增殖技术

尖刀蛏[Cultellum scalprum(Gouid)],俗称剑蛏, 为暖水性贝类,在闽、浙沿海广泛分布,是良好的增养殖品种。尖刀蛏喜栖息于中潮区及潮下带,营穴居生活, 属广温、广盐性双壳软体动物。它壳薄肉嫩、美味可口、风味独特,深受消费者喜爱,且保活保鲜度好,具有很高的经济价值。福建省霞浦县福宁湾尖刀蛏久负盛名,     

淡水有核珍珠养殖技术

淡水有核珍珠生产具有周期短、见效快的特点,江西省上高县从90年代末期开始养殖有核珍珠,目前养殖规模已发展到上万亩,现将有关养殖技术总结如下:一、养殖水面池塘面积一般在5亩以上,山塘小水库面积一般在20亩以上,水深要求在1.5m以上,水质无污染,水源充沛,进排水方便。二、亲蚌的选择1.选择自繁自养的三角帆蚌亲种,蚌龄2龄~4龄;外购天然三角帆蚌作亲种,一定要到现场进行观察了解,疫区蚌坚决不要,以免传染疫病。2.手术蚌的要求 一是制片蚌一般2龄,要求体质健壮,外套膜、边缘膜色白细嫩,闭壳肌强劲有力。二是插片蚌一般3龄~4龄,规格为壳长1…     

Fish and mussels: Importance of fish for freshwater mussel conservation

Co‐extinctions are increasingly recognized as one of the major processes leading to the global biodiversity crisis, but there is still limited scientific evidence on the magnitude of potential impacts and causal mechanisms responsible for the decline of affiliate (dependent) species. Freshwater mussels (Bivalvia, Unionida), one of the most threatened faunal groups on Earth, need to pass through a parasitic larval (glochidia) phase using fishes as hosts to complete their life cycle. Here, we provide a synthesis of published evidence on the fish–mussel relationship to explore possible patterns in co‐extinction risk and discuss the main threats affecting this interaction. We retrieved 205 publications until December 2015, most of which were performed in North America, completed under laboratory conditions and were aimed at characterizing the life cycle and/or determining the suitable fish hosts for freshwater mussels. Mussel species were reported to infest between one and 53 fish species, with some fish families (e.g., Cyprinidae and Percidae) being used more often as hosts than others. No relationship was found between the breadth of host use and the extinction risk of freshwater mussels. Very few studies focused on threats affecting the fish–mussel relationship, a knowledge gap that may impair the application of future conservation measures. Here, we identify a variety of threats that may negatively affect fish species, document and discuss the concomitant impacts on freshwater mussels, and suggest directions for future studies.     

Fish hosts of the freshwater mussel Unio foucauldianus Pallary, 1936

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淡水蚌类繁殖生物学研究进展

淡水蚌类指瓣鳃纠（双先纠）蚌科[Unionidae（Bivalvia）]的贝类，全世界现有168个属，1000多种，其中珠蚌属（Margaritifera）是亚洲、欧洲和美洲大陆都有分布的淡水珍珠贝。我国已经发现的蚌科也有15属140余种。它们分布于江河、湖泊、沟渠、池塘中。其中作为培育珍珠和制作珠核用的帆蚌、丽蚌等淡水贝类具有较高的经济价值。     

A protocol for stocking hatchery reared freshwater pearl mussel Margaritifera margaritifera

• 1. Freshwater pearl mussel (Margaritifera margaritifera L.) populations are under serious threat of extinction throughout their geographical range and only a few remnant populations are recruiting to adulthood. Consequently, M. margaritifera is classified as endangered on the International Union for Conservation of Nature Red List.
• 2. Several institutions across many countries have set up Ark sites at hatcheries to culture and rear young M. margaritifera from population remnants, with the intention of stocking these juveniles into rivers. The release location must fulfill the habitat requirements for the full life‐cycle of the species, so they can contribute to the next generation and thus the long‐term recovery of the species. However, little research or advice exists about how to decide if river environments are suitable for stocking.
• 3. A protocol is presented for determining whether a M. margaritifera population will benefit from stocking hatchery reared juveniles and how to identify suitable areas. Stocking locations are considered from catchment scale to microscale using water quality (reach), macrohabitat (site) and microhabitat, including physicochemical properties of the substratum (spots).
• 4. A case study of the River Esk in north‐east England, is incorporated to exemplify the myriad of considerations surrounding attempts to conserve M. margaritifera, and describes how implementation of the protocol can structure and assist stocking programmes. Copyright © 2010 John Wiley & Sons, Ltd.

     

Reproductive ecology of the threatened and endemic freshwater mussel Lampsilis bracteata

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The role of adaptive resistance in a widespread freshwater mussel species

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Estimation of gut contents of freshwater mussel, Lamellidens marginalis L.

This study examined the food organisms found in the gut of freshwater mussels, Lamellidens marginalis L. A total of 34 taxa of food organisms were recorded, out of which 30 taxa belonged to phytoplankton and four taxa to zooplankton. Both the groups comprised three families each: Cyanophyceae (blue‐green algae), Chlorophycea (green algae) and Bacillariophyceae (diatoms) constituted phytoplankton, whereas Euglenaceae, Chlamydodontidae and Brachionidae belonged to zooplankton. The total number of frequencies of phytoplankton (n=537) were almost nine times more than that of zooplankton (n=60). When blue‐green algae, green algae, diatoms and zooplankton (all the three families together) were tested for significant difference (P<0.05) following Duncan's multiple range test, the result showed only two groups. Blue‐green algae, green algae and zooplankton were not significantly different (P<0.05), forming group A, whereas diatoms were significantly different from others, forming group B. The present study showed that the maximum number of organisms that mussels feed upon belong to green algae, followed by diatoms, blue‐green algae and few taxa of zooplankton.     

The status of the freshwater pearl mussel Margaritifera margaritifera Linn. in Scotland

1. One hundred and sixty rivers in Scotland with historical records of freshwater pearl mussel Margaritifera margaritifera were surveyed between 1996 and 1999 for the presence of the species. 2. M. margaritifera populations were classed as either ‘extinct’ (no mussels remaining), ‘not currently viable’ (ranging from only dead shells present to no juveniles present, regardless of the number of adults found), or ‘functional’ (at least one juvenile was found, regardless of the overall numbers of adults present). 3. M. margaritifera populations could be classed as ‘functional’ in only 52 rivers (34% of total surveyed) and in only 17 of these were juveniles below 20 mm (5 yrs old) present. Furthermore, in only 10 of these functional rivers were mussels also still considered either to be common or abundant and these included both large easterly‐flowing rivers and small western rivers and streams. 4. In approximately two‐thirds (101) of the 155 rivers occupied 100 years ago, M. margaritifera is now extinct or is about to become extinct. Furthermore, analysis indicates that the rate of mussel population extinction has accelerated since 1970, with a recent average of two mussel river extinctions per year. 5. The predominant threat to the mussel populations has undoubtedly been pearl fishing. This has been occurring at every river, even in the most remote northwest areas, where most of the ‘functional’ populations remain. Recent legislation has provided full protection to M. margaritifera, so that all pearl harvesting is now illegal. 6. Locally, river engineering and host salmonid stock decline poses a serious threat and eutrophication has already eliminated populations in southern and eastern Scotland. 7. In every part of its global range, M. margaritifera has declined substantially and is now either threatened with extinction or is highly vulnerable. Based on recent estimates from across the species range, it appears that Scotland now probably holds at least half of the world's remaining functional M. margaritifera populations. Copyright © 2000 John Wiley & Sons, Ltd.     

淡水育珠蚌疾病临床诊断若干重要问题的探讨

蚌病防治难,首先是蚌病临床诊断难。几年来,我们从浙江省１２个县市及赣、鄂等省３００多病例２０００多样品蚌的诊断、治疗和跟踪调查的实践中,逐渐探明了多种病原、病症和复杂多样的病理变化之间的关系。总结了一些简便易行的临床诊断方法,从而使蚌病的有效防治率达到９０％以上。