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大川河虎嘉鱼数量变动及其原因的探讨 总被引：1，自引：0，他引：1
虎嘉鱼Hucho bleeker kimura是长江上游的濒危珍稀鱼类，数量极其稀少，分不布极为狭窄。十多年来。四川西部，陕西太白等地陆续发现虎嘉鱼。但是，其确切的分布区域却很少报道，数量资料更为少见。为此，本文就四川芦山虎嘉鱼的分布区域，数量构成。产卵群体作一初步报道。并探讨其数量变动原因，为保护、繁殖虎嘉鱼提供科学依据。 相似文献
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本文报导虎嘉鱼(Hucho bIeekeri K.)的食性及食物消化的研究结果,其食性以水生昆虫和鱼类为主食。虎嘉鱼是较有经济价值的鱼类,这一研究对虎嘉鱼的开发和利用及人工养殖提供了科学依据。 相似文献
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本文对分布于滇桂黔三省区的18种金线的体鳞覆盖程度、侧线鳞（孔）数、体鳞大小、侧线鳞与体鳞比较、体鳞辐射沟数和辐射沟的分布等七个性状作了比较研究，证明体鳞特征可作为金线肥鱼类属种间分类的重要依据，文中对金线鱼类体鳞进化趋势作了补步探讨，证明作者将侧线鳞与体鳞一致的金线并入近金线属是合理的。此外，由鳞片结构证明无眼金线鱼与麦田河金线亲缘上较相近，可能由共同祖先分化而成。 相似文献
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中国金线Ba鱼类的体鳞研究 总被引：1，自引：0，他引：1
本对分布于滇桂黔三省区的18种金线Ba的体鳞覆盖程度、侧线鳞（孔）数、体鳞大小、侧线鳞与体鳞比较、体鳞辐射沟数和辐射沟的分布等七个性状作了比较研究，证明体鳞特征可作为金线肥鱼类属种间分类的重要依据，中对金线Ba鱼类体鳞进化趋势作了初步探讨，证明作将侧线鳞与体鳞一致的金线Ba并入近金线Ba属是合理的。此外，由鳞片结构证明无眼金线Ba鱼与麦田河金线Ba亲缘上较相近，可能由共同祖先分化而成。 相似文献
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本文提出对大川河永生生物与虎嘉鱼生态位的初步研究结果:①大川河水生生物中藻类植物53属,浮游动物21属,水生昆虫14属,鱼类8属(9种)。②虎嘉鱼的生态位在大川河水生生物中处于能量的终极,食物链的顶端。 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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The literature presents a confusing number of macroscopic maturation scales for fish gonads, varying from over-simplified
scales comprising three to four stages to highly specific and relatively complicated nine-stage scales. The estimation of
some important life history traits are dependent on a correct assessment and use of the gonadal maturation scales, and frequent
mistakes have been made in many studies. The goal of this report is to provide a synthetic, relatively simple, yet precise
maturation scale that works for most oviparous teleost fishes. The synthetic scale proposed here is based on the correspondence
between key physiological and cytological processes of gamete development and corresponding modifications observed at the
macroscopic level. It is based on previous and ongoing studies of several fish species pertaining to some of the most important
African and Neotropical taxa, including Characiformes, Siluriformes, Osteoglossiformes and Perciformes. This scale should
allow for standardized protocols of field studies and improve intra- and inter-specific comparisons of life history traits.
Guidelines on the correct use of this scale to estimate these life history traits are provided. 相似文献
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Identifying cross‐scale patterns of ecological processes is imperative, especially in hierarchically structured riverine ecosystems. The role of abiotic factors in determining cross‐scale spatial structure of stream fish populations and communities is well studied, but less is known about how species traits drive cross‐scale patterns. We investigated the role of species traits for explaining autocorrelation of stream fish abundance at spatial scales ranging from local stream reaches to major basins. We calculated intraclass correlation coefficients (ICCs) representing abundance autocorrelation within species (N = 47) at each of five spatial scales. A hierarchical Bayesian regression then modelled ICCs against spatial scale with the resulting regression coefficients modelled as functions of species traits. Finally, we ordinated the scale‐by‐species ICC matrix to calculate an overall metric describing species whose abundances were autocorrelated along a gradient of large to small scales, and modelled this metric as a function of species traits. Abundances of most species were autocorrelated at smaller spatial scales. Maximum fecundity had a significant positive relationship with abundance patterns across spatial scales. Species habitat affinities and body forms were significantly associated with overall abundance patterns across spatial scales: populations of upland/lotic‐affiliated species adapted to streams with high flow correlated at small (≤10 km2) spatial scales. Lowland/lacustrine species with laterally compressed bodies showed little correlation across scales. The appropriate spatial scale for modelling abundance is determined not only by exogenous (e.g. environmental) factors, but also endogenous factors, like traits. Careful consideration of traits and life history will aid researchers in designing more effective and efficient surveys and analyses. 相似文献
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Studies of epidermal papillomatosis in fish populations have only rarely focused on the intensity of the disease, i.e. the number and size of papillomas. Furthermore, the methods used to evaluate the intensity of papillomatosis have not been standardized. We tested the reliability of a method based on counting of scales covered by papilloma tumours in roach, Rutilus rutilus (L). In addition, we studied the frequency distributions of the number of scales covered by papillomas within populations, evaluated the correlation between the prevalence and mean intensity of the disease among populations and examined the intensity of papillomatosis in roach with respect to sex and size of fish. Reliability of the scale coverage method was high. Therefore, the method could offer an effective way to determine the intensity of papillomatosis in fish species with large scales. The frequency distribution of the scale coverage of papillomas was highly aggregated within all populations studied. The mean intensity of papillomatosis increased with the size of the fish and was higher in males than in females. However, there was no correlation between the mean intensity and prevalence of the disease among the 19 roach populations studied. 相似文献
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Jenna Vergeynst Ine Pauwels Raf Baeyens Ans Mouton Tom De Mulder Ingmar Nopens 《Ecology of Freshwater Fish》2021,30(1):73-87
Migrating fish species are worldwide in decline due to several global changes and threats. Among these causes are man‐made structures blocking their freshwater migration routes. Shipping canals with navigation locks play a dual role in this. These canals can serve as an important migration route, offering a short cut between freshwater and the sea. In contrast, the navigation locks may act as barriers to migration, causing delays and migration failures. To better understand these issues for downstream migrating fish, we studied the behaviour of European eels (Anguilla anguilla) in the Albert Canal at two scales. The mid‐scale contained a 27‐km canal pound confined by two navigation lock complexes, in which we released and tracked 86 silver eels. The small scale was a 200 × 150 m area just in front of the most downstream complex of the canal pound, where we analysed the behaviour of 33 eels in relation to the flow field resulting from a computational fluid dynamics (CFD) model. This paper discusses the factors influencing fish behaviour, and the relation between these behaviours on both scales. On the mid‐scale, migration efficiency resulted from a combination of intrinsic behaviour and flow in the canal pound. Also on the small scale, intrinsic behaviour influenced the success to pass the navigation lock. Increasing the flow would create more attraction and passage opportunities and hence facilitate migration through shipping canals, but only if this flow guides the fish through safe passage routes. 相似文献
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南极鱼类年龄与生长研究进展 总被引：4，自引：2，他引：2
南极鱼类生长相对缓慢,独特的生物学特性使其年龄鉴定较其他海区鱼类更为困难。但考虑到鱼类年龄鉴定是开展渔业资源评估的基础,因此过去一些年来,硬质部位,如鳞片、鳍条(棘)、脊椎骨以及耳石等仍成为南极鱼类的主要鉴龄材料。本文对南极鱼类年龄鉴定的方法和材料进行了总结回顾,将年龄鉴定的方法和材料进行比较,分析各自优缺点。结果显示:(1)对于具鳞的南极鱼类,因鳞片在鱼类生长过程中存在重吸收现象,因而利用鳞片及鳍条(棘)单独鉴龄所得出的结果通常小于耳石的鉴龄结果,缺乏精确性;(2)南极鱼类生活跨度较大,高龄鱼体长频次分布严重重叠,以致无法准确判断其年龄结构;(3)耳石重量法易受到特殊个体影响而误判年龄;(4)因鳍条易损坏,脊椎骨采集较为困难,且许多南极鱼类无鳞,目前大多数南极鱼类使用耳石鉴定年龄,其也成为目前最为精准的南极鱼类鉴龄方法,但同时利用鳞片和耳石重量等对鉴定结果进行验证;(5)南极鱼类尚存在无统一的鉴龄标准、人为主观性较强以及缺乏早期生活史研究等不足之处;(6)为了研究南极鱼类早期生活史,耳石微化学及微结构等方法将被广泛利用。 相似文献
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《Journal Of Applied Aquaculture》2013,25(2):51-62
Rudd, Scardinus erythrophthalmus, a European minnow, has been hybridized with golden shiner, Notemigonus crysoleucas, in an attempt to produce sterile hybrids. If these hybrids are to be used as bait, easy means of differentiating the parental species and their hybrids is needed to ensure that no rudd are being sold. The scale pattern along the keel is the easiest and quickest way to distinguish the two species and their hybrids: the keel is raised and scaleless in the golden shiner, and it has 6-9 scales in the rudd; in hybrids, the keel is scaled, but the scales have different shapes and insertions than those in the rudd. No other phenotype can be used to positively identify these groups. No phenotype can be used to separate the reciprocal hybrids. 相似文献