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采用酶学和形态学测定方法, 研究在投喂卤虫条件下长吻(鱼危)仔鱼4种主要消化酶: 胃蛋白酶、胰蛋白酶、脂肪酶和淀粉酶的活性变化以及长吻(鱼危)仔鱼口宽、全长变化。实验共进行13d, 实验结果表明: (1)长吻(鱼危)仔鱼全长、口宽的发育与其日龄表现出明显的线性正相关(RTL2=0.974, RMW2=0.964)。口宽与全长比值(MW/TL)在仔鱼开口后急剧下降, 并自7日龄开始维持在0.07—0.08, 口宽和全长处于同步发育期并表现出明显的相关性(R2=0.948), 说明7日龄(/h, days post hatching)后口宽和全长处于同步发育期, 标志仔鱼转食的开始。(2)长吻(鱼危)仔鱼初次开口时即可检测出四种消化酶的活性。5—7/h时胰蛋白酶显著高于初孵仔鱼, 与此时仔鱼开始开口摄食的行为相一致。胃蛋白酶、脂肪酶活性在仔鱼孵化后第7天即开口的第3天, 淀粉酶活性在孵化后第6天, 显著高于初次孵化出来的仔鱼。8—13/h时, 胃蛋白酶、胰蛋白酶、脂肪酶和淀粉酶活性均在较高水平平稳的波动, 标志着消化道发育逐渐健全。 相似文献
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Differences in oscillatory whistles produced by spinner (Stenella longirostris) and pantropical spotted (Stenella attenuata) dolphins 下载免费PDF全文
Pina Gruden Paul R. White Julie N. Oswald Yvonne Barkley Salvatore Cerchio Marc Lammers Simone Baumann‐Pickering 《Marine Mammal Science》2016,32(2):520-534
Acoustic recordings of two closely related species, spinner dolphin (Stenella longirostris) and pantropical spotted dolphin (Stenella attenuata), were investigated from four different geographic locations: two in the Central Tropical Pacific, one in the Eastern Tropical Pacific and one in the Indian Ocean. The two delphinid species occur in tropical and warm temperate waters, with overlapping ranges. They produce very similar vocalizations, but at the same time their calls exhibit a certain degree of intraspecific variation among different geographic locations as has been observed in other delphinid species. Oscillatory whistles (whistles with at least two oscillations in their frequency contours) were identified and manually extracted from the recordings. Whistles with four or more maxima (oscillations) occurred only in spinner dolphins and they were present in all geographic regions investigated. In addition, the oscillatory whistles with two and three maxima were significantly more frequent in spinner than in spotted dolphins. The differences in oscillatory whistles for these two species seem to be consistent across study areas and therefore, could be used in addition to other whistle features to help distinguish between them. 相似文献
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注射促黄体素释放激素类似物和地欧酮诱导大鳍■和长吻■排卵的研究 总被引:1,自引:0,他引:1
对于性成熟的大鳍Mystusmacropterus(Bleeker)野生鱼,单独注射多巴胺的抑制剂地欧酮(DOM)不能影响血清促性腺激素(GTH)水平,也不能诱导排卵;单独注射类似物LHRH-A,虽能使血清GTH水平显著升高,但仅产生较低的排卵率;而当DOM与LHRH-A结合注射却显著增强LHRH-A促进血清GTH水平升高的作用,并诱导出较高的排卵率。对性成熟的长吻LeiocasislongirostrisGunther野生鱼,使用LHRH-A+DOM作2次注射诱导排卵的效果也与注射LHRH-A加脑垂体这一传统诱导排卵方法相似。Linpe方法(LHRH-A+DOM,作1次或2次注射)避免了采集、保存脑垂体不便给生产带来的麻烦,在科鱼类的人工繁殖中,具有较高的推广价值。 相似文献
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用Wright-Giemsa和PAS染色对长吻鮠头肾、肾脏、脾脏、肝脏等器官组织的涂片、印片染色观察发现,头肾、肾脏和脾脏是其主要造血器官。红细胞、粒细胞和淋巴细胞主要在肾脏和头肾中发生,其次是脾脏。单核细胞则主要在肾脏和脾脏中发生,头肾中也有少量单核细胞产生。肝脏中无原始型血细胞,可能不是其造血器官。红细胞的发育经历四个阶段,其胞体体积经历了由大到小,由小到大再变小的"两大两小"发育过程;粒细胞的发育经历五个阶段,其胞体体积均由大变小,双叶或多叶核的粒细胞可能是衰老的粒细胞亦即核的分叶是粒细胞衰老的标志;淋巴细胞和单核细胞的发育各经历了三个阶段,两者发育成熟过程中胞体体积均由大变小。巨噬细胞由单核细胞发育而来。原血细胞和部分早期幼稚血细胞可以进行有丝分裂,部分成熟红细胞和血栓细胞可以进行直接分裂。红细胞在整个发育过程中,PAS反应均呈阴性,各类白细胞的发育过程中,PAS反应由阴性到阳性并逐渐增强,这显示随着白细胞的逐渐发育成熟,细胞内糖原物质含量逐渐增多。 相似文献
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J. P. COUGHLAN L. KITSON E. DILLANE J. DAVENPORT T. F. CROSS 《Molecular ecology resources》2004,4(4):678-679
Conservation strategies for the critically endangered Bermuda skink will require knowledge of genetic variation and population structure. We describe the isolation of six polymorphic microsatellites for this species suitable for use in population genetics studies or for monitoring success of potential breeding programmes. Tissue sampling for DNA extraction involved no blood loss or tail autonomy. Three of these loci cross‐amplify and are polymorphic in a related North American skink (Eumeces fasciatus) and should also be informative for this species. 相似文献
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We conducted a cetacean survey in the pelagic western tropical Indian Ocean (WTIO) aboard an 85-m research vessel from March to July 1995, covering 9,784 linear km. Using 25 × binoculars and line-transect methods, we recorded 589 sightings of 21 species. Stenella longirostris was the most abundant cetacean, in terms of number of individuals sighted, by an order of magnitude above any other species, while Physeter macrocephalus was the most frequently sighted, in terms of number of schools. Twelve species were widespread, seven were rare, and two were localized; our sightings include new distributional records for 12 species. Significant observations included the following: (1) Delphinus cf. tropicalis was abundant off the coast of Oman (16 sightings) and readily distinguishable in the field from D. delphis and D. capensis, (2) Balaenoptera musculus was fairly common and localized in the area of the Maldives (17 sightings), and (3) three sightings were made of an unidentified bottlenose whale tentatively referred to as Indopacetus (i. e., Mesoplodon) pacificus. We recorded 26 mixed-species cetacean schools, 43 schools with which seabirds associated, and 17 schools associated with tuna. Notable among these were mixed aggregations of Stenella attenuata, S. longirostris, yellowfin tuna, and seabirds. The cetacean community of the WTIO was similar to that of the eastern tropical Pacific (ETP) and the Gulf of Mexico (GM) in several respects. First, differences in abundance rank of individual species were small, with the result that common species were common and rare species were rare, regardless of ocean. Second, these differences in abundance were due primarily to differences in encounter rate, which varied with ocean by as much as 3,000%, and less so to school size, which generally varied less than 100%. Third, regardless of ocean, three species comprised the majority of cetaceans in the community, Stenella attenuata, S. longirostris, and S. coeruleoalba, representing 62%-82% of all individuals for all species. However, the rank order of abundance for these three species differed with ocean. Most notably, S. attenuata was abundant in the ETP and GM (abundance rank = 2 and 1, respectively) but much less common in the WTIO (abundance rank = 6). Although habitat preferences for S. attenuata appear to overlap considerably with those of S. longirostris in the ETP, our results suggest there may actually be significant differences between these two species. Detailed analysis of oceanographic correlates of distribution will be necessary in order to understand fully the habitat requirements of these pelagic dolphins, often the most conspicuous elements of tropical cetacean communities around the world. 相似文献
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Samples of the polymorphic cladoceran Bosmina longirostris were collected in several lakes and ponds in Western Germany between 1993 and 1999. The shape of the first antennule was used as a qualitative criterion to classify 1241 individuals to three morphs (`longirostris', `cornuta', `pellucida') according to Lieder (Crustacea: Cladocera: Bosminidae. Stuttgart, Germany: Gustav. Fischer Verlag, 1996). Eight morphometric variables were subsequently measured in each individual to quantify size‐ and shape‐related features. Principal component and discriminant analyses were used to describe the morphological variation within and among the three morphs. Seasonal environmental changes modified several traits and thus, cyclomorphosis accounted for a high proportion of within‐morph variation. However, there was no gradual change from one morph to another. As well among‐morph variation was considerably greater than within‐morph variation. Consequently, the disagreement between the qualitative pre‐classification and the assignment basing on morphometric discriminant functions was low (4.6–12.0%). Considering that each morph is morphologically well‐defined, and that the different morphs coexisted over several generations in the same lake we conclude that they represent different species rather than variants of one polymorphic species. Therefore, we recognize beside the nominal taxon Bosmina longirostris ( 26 ) two more species: Bosmina cornuta ( 10 ) and Bosmina pellucida 30 . 相似文献
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William E. Mills Dean E. Harrigal Sheldon F. Owen William F. Dukes Daniel A. Barrineau Ernie P. Wiggers 《The Journal of wildlife management》2011,75(5):1218-1221
Capturing sufficient numbers of marsh birds for telemetry studies is difficult due to the secretive nature and inaccessible habitat of the birds. We experimented with thermal imaging technology to locate clapper rails and subsequently capture them from an airboat in South Carolina tidal marshes. This method produced a capture rate of up to 19.2 rails/hr, which exceeded other capture rates in the literature. We believe this technique will improve capture efficiency for clapper rails, and potentially other secretive marsh birds, enhancing opportunities for studying these important species. © 2011 The Wildlife Society. 相似文献
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