共查询到20条相似文献,搜索用时 15 毫秒
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为比较山美水库两种入侵齐氏罗非鱼(Coptodon zillii)和伽利略罗非鱼(Sarotherodon galilaeus)种群的繁殖生物学特征,于2021年3—10月份在山美水库逐月采样,分析了繁殖时间、性比、绝对繁殖力、相对繁殖力和成熟卵径等特征。结果表明,两种罗非鱼均于4月份开始繁殖,齐氏罗非鱼繁殖高峰为7月, 10月结束繁殖;伽利略罗非鱼繁殖高峰为6月, 9月结束繁殖。齐氏罗非鱼平均绝对繁殖力为(4009.85±1305.69)粒、平均体重相对繁殖力为(67.32±15.63)粒/g、平均体长相对繁殖力为(31.31±5.03)粒/mm;伽利略罗非鱼平均绝对繁殖力为(1701.85±591.29)粒、平均体重相对繁殖力为(6.46±0.87)粒/g、平均体长相对繁殖力为(8.22±2.33)粒/mm;齐氏罗非鱼的绝对繁殖力、体重相对繁殖力和体长相对繁殖力均显著高于伽利略罗非鱼,平均成熟卵径则显著小于伽利略罗非鱼。齐氏罗非鱼和伽利略罗非鱼繁殖群体的雌雄性比分别为1.59和1.83,两个种群的雌雄性比无显著差异,但均显著偏离1﹕1。研究表明两种共同入侵的罗非鱼种群具有不同的繁殖... 相似文献
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人工饲养下亚河豚的行为生物学研究 总被引:1,自引:1,他引:0
本文报道了2头雄性亚河豚“Vater”和“Baby”的各种行为。研究表明,饲养池的大小直接影响豚的行为;由于亚河豚和白豚生存的环境不同,导致了它们身体结构的差异,从而表现出不同的行为方式。 相似文献
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THE ORIGIN OF THE SPINNING APPARATUS IN SPIDERS 总被引:3,自引:0,他引:3
- 1 Previous attempts to explain the evolution of spider silk have relied heavily on conjecture. The formulation of testable historical hypotheses to replace such speculation is discussed.
- 2 The importance of phylogenetic reconstructions and other historical hypotheses for use in generating and testing hypotheses concerning the evolution of specific adaptations is examined. Recent ideas on arachnid phylogeny are reviewed and their relevance to the problem of silk evolution in spiders is explored.
- 3 Evidence from the analysis of three historical problems (origin of spinnerets, origin of silk glands, original selective pressure favouring evolution of silk) is reviewed from three different frames of reference (in-group analysis, out-group analysis, convergence analysis). Several lines of evidence are found which suggest that silk use originated in spiders due to selective pressures associated with reproduction (specifically, the transfer of sperm or the protection of eggs).
- 4 The prevalence of segmental appendages retained for use in manipulating genital products in both arachnids and non-arachnid arthropods and the probable placement of spinnerets near the genital opening in ancestral spiders suggest that spinnerets represent modified gonopods.
- 5 The most primitive types of silk glands are retained in virtually all spiders, in part, for use in the construction of sperm webs and egg sacs. Similar silk glands are found near the genital opening in many male spiders and used in building a portion of the sperm web.
- 6 The silk of adult arthropods other than spiders is used largely in manipulating or protecting sex cells. If there are multiple functions, use in reproduction is typically one of them. Thus, there is evidence for strong selective pressure favouring the evolution of silk for use in reproduction.
- 7 Two hypotheses are proposed which are consistent with the conclusion that silk in spiders evolved for reproductive needs (the spermatophore-sperm web and egg sac hypotheses). Testable predictions of each hypothesis are proposed.
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中国稻田蜘蛛群落结构研究初报 总被引:28,自引:4,他引:28
通过近30a的调查研究,中国稻田蜘蛛群落的物种组成,经不断分类鉴定,有22科、108属、375种,其中已定出种名的有337种,未定种名的38种。22科中有优势科8个,优势属13个,及17个优势种,但优势科中不一定都含有优势属或优势种。 相似文献
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中国红螯蛛属两新种及两种雄蛛新发现(蜘蛛目:管巢蛛科) 总被引:1,自引:0,他引:1
本文记述红螯蛛属2新种,即宁明红螯蛛Cheiracanthiumningmingensis,sp.nov,和思茅红螯蛛Cheiracanthiumsimaoensis,sp.nov及2种雄性的补充描述,即粗美红螯蛛CheiracanthiumexquestiumZhangetZhu,1993和纤红螯蛛CheiracanthiumfibrosumZhangetal,1994模式标本保存于湖南省生物研 相似文献
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烟台地区葡萄根瘤蚜(Phylloxera vitifoliae Fitch)观察 总被引:5,自引:0,他引:5
葡萄根瘤蚜是葡萄栽培事业上的一种大害虫,也是国际重要检疫对象之一。 1954年9月苏联来华植物保护与植物检疫考察组奥波连斯基专家在烟台张裕公司西葡萄山发现了葡萄根瘤蚜之后1),政府对此害虫极为重视,曾先后数次组织专家进行视察。1955年9月农业部委托山东大学生物系负责主持有关葡萄根瘤蚜的生活史,寄 相似文献
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THE BIOLOGY OF MYCORRHIZA IN THE ERICACEAE 总被引:2,自引:1,他引:1
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THE BIOLOGY OF MYCORRHIZA IN THE ERICACEAE 总被引:11,自引:4,他引:7
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NOTES ON THE BIOLOGY OF AZOTOBACTER 总被引:3,自引:1,他引:2
H. L. JENSEN 《Journal of applied microbiology》1951,14(1):89-94
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THE BIOLOGY OF MYCORRHIZA IN THE ERICACEAE 总被引:10,自引:7,他引:3
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THE BIOLOGY OF MYCORRHIZA IN THE ERICACEAE 总被引:3,自引:3,他引:0
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THE BIOLOGY OF MYCORRHIZA IN THE ERICACEAE 总被引:4,自引:4,他引:0
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THE BIOLOGY OF MYCORRHIZA IN THE ERICACEAE 总被引:9,自引:5,他引:4
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