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41.
SPF级金黄地鼠的主要生物学特性 总被引:1,自引:0,他引:1
目的测定SPF级金黄地鼠的生物学特性数据,为生物制品的生产、检定及科学研究提供标准化的SPF级金黄地鼠。方法在5周龄、10周龄和30周龄群体中随机抽样20只地鼠,雌雄各半。测定生长发育、繁殖性能、淘汰种鼠干物质及粗脂肪含量、解剖学特性以及血液生理生化指标等生物学特性指标。结果从SPF级金黄地鼠的生长和繁殖特性来看,通过严格的选择和淘汰,SPF级金黄地鼠的生长、繁殖等特性已保留下来,同比原种群得到进一步提高。其体重和主要脏器重量、脏器系数的数据在5、10和30这三个日龄段基本稳定一致,呈现正常的生长规律;该鼠群的血常规、血液生化指标和免疫指标也比较稳定一致,个体间的差异很小。结论本实验测定的SPF级金黄地鼠的主要生物学特性,将为SPF级金黄地鼠进一步标准化提供极其重要的依据。 相似文献
42.
Generalization and categorization of spectral colors in goldfish I. Experiments with one training wavelength 总被引:1,自引:1,他引:0
Manuela?Kitschmann Christa?NeumeyerEmail author 《Journal of comparative physiology. A, Neuroethology, sensory, neural, and behavioral physiology》2005,191(11):1025-1036
Goldfish have a tetrachromatic color vision with a high discrimination ability for spectral colors as well as for object colors.
We investigate the question whether goldfish organize the high number of discriminable colors in terms of color categories,
i.e. in a few larger groups of colors independent of wavelength discrimination. Twenty-four goldfish were trained with food
reward, each fish on one out of 13 wavelengths between 371 nm and 630 nm. In transfer tests two different wavelengths were
presented, one shorter and one longer than the training wavelength, and the choice behavior was determined. Choice frequencies
of ≥50% were assumed to indicate similarity to the training color. The wavelength ranges ≥50% were about 100 nm and twice
as large as the just noticeable differences measured in wavelength discrimination tests (Fig. 7). The ranges were surprisingly
about the same for all training wavelengths, provided the data were plotted on a wavelength scale weighted according to discrimination
ability (Fig. 4). Thus, with the training method chosen goldfish showed a kind of categorization which, however, depends on
training wavelength and discrimination ability. Generalization tests in which training wavelength and test wavelengths were
shown separately for 2 min each gave the same results as wavelength discrimination tests (Figs. 5 and 6) and are, therefore,
not indicative for color categories. 相似文献
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Mixed-rod cone bipolar (Mb) cells of goldfish retina have large synaptic terminals (10 mum in diameter) that make 60-90 ribbon synapses mostly onto amacrine cells and rarely onto ganglion cells and, in return, receive 300-400 synapses from gamma-aminobutyric acid (GABA)-ergic amacrine cells. Tissue viewed by electron microscopy revealed the presence of double-membrane-bound processes deep within Mb terminals. No membrane specializations were apparent on these invaginating processes, although rare vesicular fusion was observed. These invaginating dendrites were termed "InDents". Mb bipolar cells were identified by their immunoreactivity for protein kinase C. Double-label immunofluorescence with other cell-type-specific labels eliminated Müller cells, efferent fibers, other Mb bipolar cells, dopaminergic interplexiform cells, and somatostatin amacrine cells as a source of the InDents. Confocal analysis of double-labeled tissue clearly showed dendrites of GABA amacrine cells, backfilled ganglion cells, and dendrites containing PanNa immunoreactivity extending into and passing through Mb terminals. Nearly all Mb terminals showed evidence for the presence of InDents, indicating their common presence in goldfish retina. No PanNa immunoreactivity was found on GABA or ganglion cell InDents, suggesting that a subtype of glycine amacrine cell contained voltage-gated Na channels. Thus, potassium and calcium voltage-gated channels might be present on the InDents and on the Mb terminal membrane opposed to the InDents. In addition to synaptic signaling at ribbon and conventional synapses, Mb bipolar cells may exchange information with InDents by an alternative signaling mechanism. 相似文献
46.
Bickmeyer U Grube A Klings KW Köck M 《Biochemical and biophysical research communications》2008,373(3):419-422
The alkaloid ageladine A, a pyrrole-imidazole alkaloid isolated from marine Agelas sponges shows fluorescence in the blue-green range during excitation with UV light with the highest absorption at 370 nm. The fluorescence of this alkaloid is pH dependent. Highest fluorescence is observed at pH 4, lowest at pH 9 with the largest fluorescence changes between pH 6 and 7. Ageladine A is brominated, which facilitates membrane permeation and therefore allows for easy staining of living cells and even whole transparent animal staining. To calculate the exact pH in solutions, cells, and tissues, the actual concentration of the alkaloid has to be known. A ratiometric measurement at the commonly used excitation wavelengths at 340/380 nm allows pH measurements in living tissues with an attenuated influence of the ageladine A concentration on calculated values. The fluorescence changes report small intracellular pH changes induced by extracellular acidification and alkalization as well as intracellular alkalization induced by ammonium chloride. 相似文献
47.
To study the coexistence of sexual and gynogenetic forms, we examined the population structure of a gynogenetic complex of
the Japanese crucian carp, Carassius auratus Temminck et Schlegel, during the April–June reproductive season by collecting 1225 mature fish that migrated from Lake Suwa
to a tributary river for spawning. There were more sexual fish (about 80%) than gynogenetic fish in this complex, and the
operational sex ratio in the sexual form was female biased (males were about 20%). Mean standard length and body weight of
sexual females were larger than those of sexual males. Sex ratio was male biased in smaller fish (standard length, <8.5 cm)
but female biased in larger fish (standard length, ≥8.5 cm). We determined age by scale ring marks; the average age of sexual
females was higher than that of males, but there was no significant difference in the average age between sexual and gynogenetic
females. Sex ratio in the sexual form was more female biased for old than for young fish, and the mean size of sexual females
was larger than that of males of the same age. The clear female-biased sex ratio and age difference between sexual females
and males can be explained either by (1) higher mortality of males or by (2) female-biased sex allocation. The latter process
reduces the disadvantage of sex and contributes to the coexistence of sexual and gynogenetic forms.
Received: November 24, 2000 / Accepted: March 6, 2001 相似文献
48.
负压状态下压力变化导致鲫鱼身体组织的损伤 总被引:1,自引:0,他引:1
通过试验研究负压状态下压力变化过程对鲫(Carassius auratus auratus)的损伤,试验采用真空泵和空气压缩机在试验容器内形成不同的压力变化过程,统计不同体长的鲫经历压力变化过程后的损伤情况,并对部分受损伤的鲫进行解剖和组织观察。研究发现负压状态下压力时变导数较大的变化过程会对鲫的生存构成直接威胁,主要损伤是鱼鳔部分或全部受损,在肝胰脏、肾脏等处有明显出血点。综合分析不同试验条件对鲫损伤的情况,得到了对鲫尽可能安全的压力时变导数极限值,从而为新型环保水力设施的设计提供参考依据,起到保护渔业资源的作用。 相似文献
49.
Predation risk and feeding patterns of crucian carp 总被引:1,自引:0,他引:1
C. A. Paszkowski O.-P. Penttinen † I. J. Holopainen † W. M. Tonn 《Journal of fish biology》1996,48(5):818-828
As part of an experimental study of the direct and indirect effects of piscivory on prey fish, the diets of crucian carp Carassius carassius were compared across sections of a divided pond; two sections were stocked with crucian carp alone and two with crucian carp plus perch Perca fluviatilis . Analysis of crucian gut contents indicated that the composition of invertebrate prey did not differ in the presence v . absence of perch. However, crucians, particularly small individuals (<10cm) that were most vulnerable to predation, displayed a lower intake of invertebrate prey in sections with perch. Although diet composition differed between crucians caught in inshore v. offshore habitats (with habitat use being related to crucian size and the presence or absence of perch), no clear pattern existed between habitat and total food intake. Overall, the major effects of predators on the diet of crucian carp appeared to be caused by increased ecological density (resulting from confinement of small crucians inshore) and reduced activity levels, rather than simple shifts to safer habitats. 相似文献
50.
P. Vandewalle § A. Chikou † P. Lalèyé † E. Parmentier F. Huriaux B. Focant ‡ 《Journal of fish biology》1999,55(4):795-808
The inception and development of the cartilaginous cephalis skeleton of Chrysichthys auratus is described from hatching to about 18 days post-hatching. At hatching, no skeletal structure is present. Not until day 3 do clearly delimited cranial primordia become apparent. As in many siluriforms, the neurocranium is platybasic from the start, the suspensorium constitutes, with Meckel's cartilage and the hyoid bar, a single cartilaginous element, and the junction between the front and rear of the neurocranium is complete on day 4. By day 8 the quadratomandibular joint has formed and the tectum posterius has appeared. Cartilage reduction first affects the trabecular bars, then, markedly, the visceral arches. By day 18 the braincase floor has almost disappeared. 相似文献