共查询到19条相似文献，搜索用时 218 毫秒
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崇明长棘吻虫病的病原是崇明长棘吻虫(Rhadinorhynachus chongmingnensis),主要寄生在鲤鱼肠壁上,中间寄主是模糊裸腹蚤。鲤鱼自夏花至成鱼都可被寄生,发病严重的池,感染率100％,死亡率60％。可用四氯化碳拌饵投喂,进行防治,也可以用漂白粉或生石灰清池,杀死虫卵及中间寄主,达到预防目的。 相似文献
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<正>猪棘头虫病(钩头虫病)是由蛭形巨吻棘头虫寄生在猪的小肠(主要是空肠)内所引起的寄生虫病。全国各地普遍流行。1病原蛭状巨吻棘头虫虫体甚大,长圆柱形,淡红色或乳白色,前部较粗,后部较细。体表有环状横皱纹。头端有一个可伸缩的吻突。吻突小,呈球形,有5～6行向后弯曲的吻钩,其中部的吻钩最大,后面的吻钩最小。无消化器官。雄、雌虫体差别很大。雄虫较短,仅7～ 相似文献
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长江中游长吻Ｗｅｉ幼体长江丽棘虫感染率高达８４．５％,感染强度为１６．４（１￣４８）。１龄长吻Ｗｅｉ感染率９６．３％,感染强度１７．１;２龄鱼为７６．６％、１５．６;３龄鱼体内未检出长江丽棘虫。８０％长江丽棘虫集丛分布在长吻Ｗｅｉ小肠的前段,雌体明显多于雄体。长江丽棘虫在长吻Ｗｅｉ幼体种群中的分布为聚集分布形式。 相似文献
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网箱鲤鱼白云病的防治白云病是一种细菌和寄生虫综合症，常常与小瓜虫、口丝虫、车轮虫、斜管虫、三代虫病、竖鳞病、水霉病、赤皮病。等并发，特别是对集约化养鱼传染迅速，感染率高，治疗困难，死亡率可达１０～６０％。若不及时治疗，造成严重的经济损失，影响生产者的... 相似文献
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隐藏新棘虫种群生物学研究 总被引：13，自引：3，他引：13
剖检了１２８尾黄鳝，新棘虫的感染率高达６５．６％，感染强度为９．１，感染率和感染强度与黄鳝的体长呈正相关关系。该种寄生虫的性比符合１∶１的比例，但３２ｃｍ以下的黄鳝体内的雄性棘头虫明显地较多。９４％的虫体分布在黄鳝小肠前段３ｃｍ以内。寄生虫数超过３０以上的宿主生殖腺有萎缩现象 相似文献
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近年来，哈尔滨地区部分渔场及个体户养殖的鲤鱼种、鲤成鱼连续发生线虫病，感染率高达30％～50％，并迅速蔓延，严重影响了鱼产量。尤其越冬后期至饲养初期，在水温升高、绦虫生长加快的情况下，常发生大量死亡，死亡率可高达45％。为了控制此病的流行，我们分别用敌百虫药饵和别了药饵进行了治疗对比试验，现将试验情况总结如下：一、流行增况调查哈尔滨市水产研究所鲤鱼种池感染绦虫病，共解剖137尾，感染率32．l％；哈尔滨市水产研究所试验渔场一鲤鱼种地感染绦虫，共解剖72尾，感染率27．8％；1996年5月初，本所一高产成鱼池，投放鱼种… 相似文献
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五种鱼的鳞被复盖过程及其同生长的关系 总被引：1，自引：0，他引：1
用茜素红染色法观察研究了904尾鲤鱼、429尾草鱼、637尾鲢鱼、70尾鳙鱼及243尾尼罗罗非鱼的仔幼鱼。五种鱼鳞片出现时全长分别为：16—19，17—19，27—32，26—31，10-14mm。完成鳞被复盖时的全长分别为24—30，24—28，47—55，48—58，19—22mm。五种鱼鳞片出现均始于侧线，但出现部位和复盖过程可分为两类：鲤、草鱼、鲢及鳙的鳞片首先出现于躯干前部，为由前向后发展型，至于具体扩展过程，鲤与草鱼相似，鲢与鳙相同；罗非鱼的鳞片首先出现于尾柄，为由后向前发展型。鳞片出现、复盖过程同全长及年龄的关系的比较观察和回归分析表明，这一过程的始末及速度主要同体长增长有关，同年龄关系不大。鳞被发育过程不仅反映了不同鱼类的不同生长规律，亦可能有助于认识鱼类间的亲缘关系。 相似文献
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Mouth size was examined in larvae and juveniles of three cyprinid fish species: grass carp (Ctenopharyngodon idella Val.), silver carp (Hypophthalmichthys molitrix Rich.) and bighead carp (Aristichthys nobilis Rich.). A linear relationship was found between mouth size and the total length of fish, from the initial exogenous feeding stage up to 20–30 mm. Based on the mouth size, the size of the prey which could be consumed was calculated assuming 45° of mouth opening for optimum prey width and 90° for maximum prey width. Food particle size considered to be suitable for commencement of feeding amounted to 50–90 μm for silver carp larvae, 90–150 μm for grass carp larvae and 150–270 μm for bighead carp larvae. These criteria can be applied to moving rotifiers and nauplii as well as to the motionless particles of compound, dry diets. 相似文献
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Two new species of myxozoans from the Japanese anglerfish, Lophius litulon, are described using myxospore morphology and small subunit rDNA sequences. Ceratomyxa anko sp. n. is a parasite of the gall bladder and had a prevalence of 57%. Mature spores of C. anko sp. n. are arcuate to crescent shaped with valves tapering to rounded tips. A prominent sutural line runs centrally between the round adjacent polar capsules containing the polar filament coiled two to three times. Spore measurements: length 10.8 (9.7-11.9) microm, width 41.9 (36.9-47.2) microm, polar capsule diameter 4.6 (4.1-5.3) microm. Ceratomyxa anko sp. n. can be distinguished from other Ceratomyxa spp. due to its spore dimensions and shape. Zschokkella lophii sp. n. is a parasite of the urinary bladder and had a prevalence of 70%. Mature spores are ellipsoidal to semicircular with bluntly pointed ends. The sutural line is curved or sinuous and the valves have no discernable surface ornamentation. Two almost spherical polar capsules are located separately in the ends of the spore, opening in almost opposite directions and contain the polar filament with five coils. Spore measurements: length 20.1 (16.8-24.0) microm, width 14.9 (12.7-16.8) microm, polar capsule diameter 5.1 (3.6-5.8) microm. Zschokkella lophii sp. n. can be distinguished from other Zschokkella spp. due to the terminal opening of the polar capsules within the spores and the site of infection within the host fish. In the phylogenetic analyses, C. anko sp. n. grouped with other members of the same genus forming a monophyly. Zschokkella lophii sp. n. forms a discrete clade with another Zschokkella sp. that infects the urinary bladder of marine fish. This grouping forms a sister clade to one containing members of the genus Parvicapsula, all of which are parasites of the urinary system in marine fish. 相似文献
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Grass carp (Ctenopharyngodon idella Val.) is well known for its efficacy as a biological weed control agent. The young of the species were observed to feed avidly on mosquito larvae in the present set of experiments. The fish 98–185 mm in length appeared to be comparatively more voracious in feeding than the larger ones (220 mm). The larger grass carp (252 mm), common carp (95–105 mm) and silver carp (97–115 mm) did not feed on the larvae at all. Thus, the small grass carp are expected to exercise some control over the population of mosquitoes in a water body. The propensity of the fish to feed on vegetation is likely to ensure better access to the shallow areas where mosquitoes generally breed. The grass carp can be listed among the larvivorous fishes along with other cyprinids. 相似文献
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调查三峡水库正常运行期(2011-2015年)库区干流5个江段(秭归、巫山、云阳、涪陵、江津)的鱼类资源,对库区干流四大家鱼的时空分布特征进行研究,并探讨三峡库区四大家鱼受上游水电开发以及库区其他因素影响的情况,旨在为三峡库区四大家鱼保护措施的提出提供基础数据支撑。研究结果表明:四大家鱼在渔获物中的数量百分比从2011年的3.52%下降到2015年的1.86%,而重量百分比则先从2011年的13.47%迅速上升到2012年的28.06%,然后波动下降到2015年的24.30%,其中鲢、鳙、草鱼均在数量百分比上呈现波动下降趋势,而在重量百分比上则均呈现先上升后下降的趋势;5年间,四大家鱼的主要分布区域逐渐从涪陵至秭归江段转移到云阳和秭归江段,其中鲢、鳙、草鱼的主要分布区域均从云阳至秭归江段转移到云阳和秭归江段。三峡库区四大家鱼群体面临的主要问题是金沙江梯级水电站运行对其产卵活动的影响以及库区普遍的过度捕捞。 相似文献
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Abstract Freshwater fish in Czechoslovakia were examined for species of the genus Sphaerospora Thélohan, 1892 and for myxosporean life cycle stages in the blood. In addition to perch infected with S. pectinacea Bocharova & Donets, 1974, renal tubules of seven host species harboured thus far unidentified Sphaerospora species. A new species, S. gobionis sp.nov. is described from renal tubules of Gobio gobio. In populations of Gobio gobio, Tinea tinea and Rutilus rutilus harbouring infections with different Sphaerospora species, organisms identified as mobile myxosporean life cycle stages were detected in the blood, where they undergo a proliferative cycle. These organisms were reminiscent of stages in the blood of common carp fingerlings, supposedly identical with Sphaerospora renicola Dyková & Lorn. It is possible that the blood stages found in the three cyprinid hosts represent stages of the life cycle of their respective Sphaerospora species. If this is correct, further studies may show if the presence of proliferative stages in the bloodstream is a character distinctive of the genus Sphaerospora. 相似文献
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The preferred temperatures of grass carp, Ctenopharyngodon idella (Valenciennes), and brema carp, Megalobrama amblycephala (Yih), were determined individually and together in both horizontal and vertical gradients. No significant difference was found by two methods between the preferred temperatures in either species of carp (28.0-28.5 oC) when the fish were placed individually. However, when the two species of carp were placed together, C. idella was displaced thermally, preferring a temperature of 23.5 oC, which was significantly lower than that obtained when it was held separately. This suggests that, if both species of carp are placed in ponds forming part of a Chinese polyculture system, C. idella will seek out a lower temperature as a mechanism to avoid competition, and therefore, the growth of this species will be reduced. 相似文献
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Abstract. During a survey for coccidian infections of 135 Australian freshwater fish belonging to 14 species, two new Eimeria species, E. philypnodoni sp. nov. from Philypnodon grandiceps and E. ashburneri sp. nov. from Macquaria ambigua , and three new Goussia species, G. langdoni sp. nov, from Macquaria ambigua, G. callinani sp, nov. from Hypseteotris compressa and G. lomi sp. nov. from Maccullochella peeli , were found. Epieimeria anguillae and a Goussia sp. from Anguilla australis and A. reinhardti were recorded. These are the first records of coccidia from Australian fishes. 相似文献