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江鳕耳石年轮   总被引:4,自引:0,他引:4  
介绍了江鳕耳石年轮的特点探索出了江鳕耳石年轮形成时期及生殖洄游、生长发育的关系。  相似文献   

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江鲽在卵和卵黄囊期仔鱼发育阶段生化成分的变化   总被引:4,自引:0,他引:4  
哈.  SM 殷名称 《动物学报》1993,39(3):272-279
本文研究和测定了江鲽( Platichthys flesus L.)在卵和卵黄囊期仔鱼发育阶段水分、钠、钾、脂肪和蛋白质的含量变化。含水量在卵和仔鱼发育期基本保持在90—92%,在仔鱼进入初次摄食期时可降到89%左右。初孵仔鱼具一大卵黄囊,含水量高达93.3%,起“浮力器官”(buoyancy organ)的作用。钠、钾离子含量在卵受精和仔鱼出膜后波动剧烈,呈“上升—下降—再上升”式型。脂肪和蛋白质含量在卵和仔鱼早期发育和饥饿期均呈明显线性下降。同时,本文还就生化成分变化和海洋浮性鱼卵及其仔鱼的生态习性的关系作了初步探讨。  相似文献   

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Journal of Ichthyology - The feeding of burbot Lota lota was studied in the modern conditions of the Kuibyshev Reservoir. With the decrease in the abundance of ruff Gymnocephalus cernuus in the...  相似文献   

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We developed 21 polymorphic dinucleotide microsatellite loci, (CA)n and (CT)n, for the Holarctic freshwater fish, Lota lota, using an enriched genomic library protocol. The species has an interesting life history because winter‐spawning adults migrate over long distances to form spawning aggregations, a behaviour which should maintain genetic homogeneity across large spatial scales. Availability of the reported microsatellites will facilitate the investigation of population genetic structure with regard to postglacial colonization history and conservation strategies. The primers were screened on 30 individuals from a natural population (Lake Constance, southern Germany), revealing three to 24 alleles per locus with expected heterozygosities ranging from 0.48 to 0.93.  相似文献   

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This article is based on a study of traditional lifestyle practices in the Sandy Lake First Nation community in northwestern Ontario, considering some of the benefits and risks of reintroducing off-the-land food sources, specifically as they relate to the burbot (Lota lota L.). This article concentrates, therefore, on four avenues of exploration: (1) the “nutrition transition” in the First Nations population, (2) the meaning of a traditional diet in the Sandy Lake First Nation, (3) a nutritional value analysis of the burbot to determine its energy content and medicinal properties, and (4) the plausibility of reintroducing off-the-land food sources into the Sandy Lake First Nation community. We argue that though there may be health advantages to the reintroduction of off-the land food sources into First Nations contemporary diets, these benefits will be realized only if practiced according to historical dietary traditions drawing from critical parts of animal tissues to maximize nutrient intake.  相似文献   

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Journal of Ichthyology - The study presents data on the biology of the marginal population of burbot Lota lota from the lower reaches of the Volga. Individuals aged from 3 to 7 years were recorded...  相似文献   

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Records of burbot Lota lota (L.) captures from the early nineteenth century to the present have been gathered and arranged watershed by watershed in chronological order. Most are from eastward-flowing river systems from Durham southwards to the Great Ouse, but a few records from westward-flowing systems are considered. In many areas the records imply a decline of burbot numbers and distribution during the present century, though burbot may never have been more than locally abundant. Local over-fishing, pollution and habitat changes are considered the most likely causes of decline. Conservation measures seem desirable.  相似文献   

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The parasite fauna of the burbot (Lota lota) within its natural range is reviewed. The sent paper summarizes the data on parasites of the burbot from water bodies of Eurasia and North America, based on published monographs, reviewed journals, scientific reports, conference contributions, and PhD theses. The checklist includes all protozoan and metazoan parasites of the burbot. A total of 242 parasite species/taxa were recorded in the burbot (Ki-netoplastomonada--4, Parasitomonada--3, Coccidiomorpha--1. Microsporidea--3, Myxosporidia--35, Pleurostomata--1. Cyrtostomata--3, Peritricha--20. Protozoa incertae sedis--1. Monogenea--8, Cestoda--23, Digenea--50. Nematoda--36, Acanthocephala--28, Hirudinea--11. Bivalvia--5, Crustacea--10). Most parasites belong to digenean trematodes. Most of these species (183 species/taxa) were recorded on Eurasian and only 92--in North America fishes. Several parasite species recorded from the burbot are discussed in relation to host specificity and their geographical distribution.  相似文献   

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The burbot (Lota lota Linnaeus, 1758) is the only freshwater species of the family Gadidae. There is a longstanding controversy about taxonomic status of the burbot from the Amur River basin. It is necessary to investigate population genetic structure and geographical differentiation among burbot populations from the Irtysh River basin and Amur River basin by mitochondrial DNA nucleotide sequence analysis. A 572 bp segment of cytochrome b and 425 bp segment of control region gene were sequenced from 4 populations. The results showed that there was lower genetic diversity of burbot in China and highly significant genetic difference between populations in the Amur River basin (P < 0.01). Demographic analysis indicated that the burbot from the Amur River basin experienced population expansion (Cytb: F S = ? 0.912 (P = 0.287), D = ? 0.399 (P = 0.375); CR: F S = ?4.771 (P = 0.015), D = ?1.523 (P = 0.03)). The data of 4 populations in China combining with the published data representing the Eurasian and North American burbot, revealed three distinct phylogenetic lineages (labelled EB, NA, Amur).  相似文献   

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