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排序方式: 共有78条查询结果,搜索用时 156 毫秒
1.
本文对棕黑锦蛇(Elaphe schrenckii)进行分类学等研究,棕黑锦蛇被认为包含两个亚种:指名亚种(Elaphe s.schrenckii)和赤峰亚种(Elaphe s.anomala),但也有学者将后者提升为种,即赤峰锦蛇(Elaphe anomala).有关该种分类问题,仍需要进一步综合考虑形态学和分子系统学分类研究.作为我国东北和华北地区体形最大的蛇种,棕黑锦蛇具有重要的生态和经济价值,但目前对其生物学特性和生态学研究极为有限,人工驯养繁育技术不成熟,过度利用导致野外种群遭到严重破坏.建议加强棕黑锦蛇生态学和人工繁育技术的研究,为有效保护和可持续利用提供科学依据. 相似文献
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Parasites are a health concern of many wildlife species, although their effect on reptiles is poorly studied. Here we examine effects of hemogregarine and external parasites on Texas ratsnake Elaphe obsoleta white blood cell (WBC) concentrations, WBC differentials, heterophil/lymphocyte ratios, packed cell volume (PCV), corticosterone concentrations and body condition. We found little evidence that either ectoparasites or hemogregarines affected the health of Texas ratsnakes. We found a seasonal increase in corticosterone, consistent with glucocorticoids priming the snakes to deal with higher predation risks later in the season. We also examined whether the potential stress of carrying a surgically implanted radio-transmitter compounds any parasitic health effects. We found no effect of transmitters on most aspects of health. We did find equivocal evidence that WBC concentrations were higher in snakes with transmitters and that PCV decreased following transmitter implantation. Although our results generally support the view that data collected using radio-telemetry are unlikely to be biased due to adverse health effects of transmitters, the growing importance of telemetry for studies of snakes and other taxa argues for further research on this topic. When possible, researchers should design telemetry studies in such a way that assessing potential heath effects of transmitters is one of the objectives. 相似文献
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采用高通量测序技术,分析比较了实验室人工饲养的王锦蛇(Elaphecarinata)、棕黑锦蛇(E.schrenckii)和赤峰锦蛇(E. anomala)3种锦蛇粪便样本的微生物多样性。结果显示,在送检的粪便样本中,Shannon多样性指数(P 0.05)和Simpson多样性指数(P 0.05)在王锦蛇和棕黑锦蛇之间有显著性差异,赤峰锦蛇与前两者均没有差异;ace与chao1指数在3种锦蛇之间没有显著性差异。共检测出8个菌门,厚壁菌门(Firmicutes)、拟杆菌门(Bacteroidetes)和变形菌门(Proteobacteria)是3种锦蛇共享菌门。在属水平上3种锦蛇的优势菌群明显不同,志贺氏菌属(Shigella)、梭状芽胞杆菌属(Clostridium_sensu_stricto_11)及拟杆菌属(Bacteroides)分别是王锦蛇、棕黑锦蛇和赤峰锦蛇粪便样本中相对丰度最高的菌属。3种锦蛇粪便微生物多样性存在着明显的差异,但其是否可以作为区分这3种锦蛇的依据还需要进一步研究。 相似文献
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埃塞俄比亚芥与诸葛菜属间杂种的基因组原位杂交分析 总被引:2,自引:1,他引:1
用幼胚培养方法重新获得的埃塞俄比亚芥(Brassica carinata A.Braun,2n=34)与诸葛菜(Orychophragmus violaceus (L.)O.E.Schulz,2n=24)的属间杂种仍为混倍体(2n=14~34),2n=34细胞的频率最高;绝大多数花粉母细胞(PMCs)表现正常的17个二价体配对和17:17的分离。基因组原位杂交分析结果表明,在所有体细胞和PMCs中不含有整条的诸葛菜染色体,2n=34的体细胞和PMCs中包含了来自黑芥(B.nigra (L.)Koch,2n=16)的16条染色体。这些具有完全或部分埃塞俄比亚芥染色体组成的细胞,可能来源于以前提出的杂种细胞在有丝分裂中完全或部分亲本染色体组分开和染色体复制,并伴随诸葛菜染色体的消除。 相似文献
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In this study, one of Doublesex genes from the common freshwater cladoceran Daphnia carinata, designated DapcaDsx1, was cloned using primers based on homologous sequences and rapid amplification of cDNA ends (RACE). qPCR was employed to quantify differences in DapcaDsx1 expression between the different sexual phases, with expression levels being higher in sexual females. The role of DapcaDsx1 in the reproductive transformation was further investigated in parthenogenetic-phase females and sexual-phase females using whole-mount in situ hybridization. This cellular localization study showed specific expression of DapcaDsx1 in the thoracic segments, second antenna and part of the ventral carapace. Higher expression levels were exhibited in sexual females compared to parthenogenetic females. This suggests that the DapcaDsx1 gene plays significant roles in switching modes of reproduction and during sexual differentiation. 相似文献
10.
Apparent decoupling of prey recognition ability with prey availability in an insular snake population 总被引:2,自引:0,他引:2
Numerous studies on the feeding behavior of snakes have reported the consistency of tongue-flick responses with their natural
diets. For representatives of widely distributed, dietary generalist species from particular localities, we can expect that
their tongue-flick responses to potential prey unavailable in their original habitats have been reduced whereas those to prey
common in the habitats have been enhanced. To test this hypothesis, intraspecific variation in tongue-flick responses to prey
chemicals was examined using ingestively naive snakes (Elaphe quadrivirgata) from dietarily different populations: populations from the main Japanese island, where the snakes' diet predominantly consists
of sympatric frogs, and from Mikura-jima Island, where no frogs occur and the snakes thus chiefly prey on lizards. We presented
chemical stimuli from six items including those from their natural and potential prey (fish, frog, lizard, mouse, water, and
cologne) to newborn snakes. Significant effects of stimuli on the tongue-flick responses were detected. On the other hand,
effects of population and interaction between stimuli and population were not significant, and individual comparisons revealed
no significant interlocality differences in responses to either frog or lizard chemicals. Thus, our hypothesis was not supported.
However, in the Mikura-jima sample, significantly fewer snakes responded to frog chemicals than in the main island sample.
The significance of the inconsistency between prey recognition ability and prey availability in the Mikura-jima population
are discussed.
Received: October 17, 2000 / Accepted: December 14, 2000 相似文献