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1.
影响漠斑牙鲆稚鱼的自残因子的研究   总被引:1,自引:0,他引:1  
漠斑牙鲆(Paralichthys lethostigma)稚鱼阶段,自残现象比较严重。本文以漠斑牙鲆稚鱼为实验对象,选取全长10.1—40.9mm的漠斑牙鲆进行试验观察。研究了密度、浑浊度、饥饿、个体大小差异对该幼鱼自残的影响程度。(1)密度、投饲量、个体大小差异对漠斑牙鲆稚鱼的自残行为影响极显著;高密度组的比低密度组自残现象严重;饱食组的自残率较1/3饱食投饲量组别的轻;个体大小差异是引起自残最重要的因子,当投喂不充足时,(10.1±0.4)—(20.3±0.3)mm组的自残现象最为严重自残死亡率为53%。(2)饥饿对自残行为影响显著,饥饿24h后自残死亡率为20%((15.0±0.4)mm组)。(3)浑浊度、饵料种类对自残行为影响不显著,在密度为20尾/L时,无浑浊度组稚鱼自残死亡率为8%,浑浊度组5%。    相似文献   

2.
昆虫肢体再生的研究进展   总被引:3,自引:2,他引:1  
王孟卿  彩万志 《昆虫知识》2004,41(2):127-131
文中就发生断肢再生的昆虫类群、出现虫态、再生的类型、再生能力、影响再生的因素、再生的生物学意义几个方面进行了综述 ,特别对猎蝽科昆虫的肢体再生有关方面做了介绍  相似文献   

3.
捕食性瓢虫是农田生态系中一类重要的天敌昆虫,种内自残和集团内捕食现象在捕食性瓢虫中普遍存在。本研究在室内通过选择性和非选择性试验比较分析了异色瓢虫、七星瓢虫及龟纹瓢虫成虫对卵的种内自残和集团内捕食作用以及卵表面的化学物质对集团内捕食作用的影响。结果表明:在非选择性试验中,3种捕食性瓢虫成虫对卵表现出相似的取食现象,即对龟纹瓢虫卵取食最多,其次为七星瓢虫卵,对异色瓢虫卵取食相对较少;在选择性试验中,七星瓢虫和龟纹瓢虫较偏好取食同种卵,对异色瓢虫卵取食均较少;而异色瓢虫喜欢取食异种卵,对同种卵取食相对较少。3种瓢虫卵经正己烷漂洗后,异色瓢虫、七星瓢虫和龟纹瓢虫成虫却未对卵表现出取食偏好性。本研究可为捕食性瓢虫组合释放与协调利用、田间集团内捕食作用评定及其在生物防治中的应用提供理论依据。  相似文献   

4.
《环境昆虫学报》2014,(6):874-878
自残现象的发生在异色瓢虫Harmonia axyridis中很是常见,为明确自残行为对其存活和生长发育的影响,在非选择性条件下我们对异色瓢虫幼虫对非姊妹卵的种内自残和对七星瓢虫Coccinella septempunctata卵的种间捕食进行了研究。结果表明,异色瓢虫取食同种卵和异种卵均可完成生长发育,与取食蚜虫相比:①其从卵到成虫及蛹期的发育历期明显缩短(P<0.05),其中1龄幼虫发育历期缩短非常明显(P<0.01);②自然条件下高死亡率的1龄幼虫的存活率明显提高(P<0.05);③2-4龄幼虫、蛹和成虫的体重变轻(P<0.05),且体长在4龄幼虫间也表现出显著差异(P<0.05)。这表明异色瓢虫种内自残和种间捕食对其在食物恶劣条件下延续种群至关重要,但对种群的繁衍却不是最理想的途径。  相似文献   

5.
附肢自残是北京幽灵蛛(Pholcus beijingensis Zhu & Song,1999)的习性之一。野外调查表明,约20%的个体至少失去1只步足;个体自残的发生率在2—7月间有显著的差异,同时第一对步足自残的比例最高(43.47%);个体失去步足的比例随着年龄的增加而增加;左侧和右侧步足失去的比率接近(1.03:1)。野外调查发现,正在交配的个体与单独生活的个体相比,步足的完整性上并无显著差别。实验室研究表明,北京幽灵蛛附肢自残后没有再生现象。通过对自残幼体与非自残幼体的3龄与4龄龄期研究,发现各处理组间并无显著的差别。步足自残被认为是北京幽灵蛛在极端情况下的“避险策略”(Bet-hedging strategy)[动物学报54(6):998-1004,2008]。  相似文献   

6.
昆虫黑化现象   总被引:3,自引:0,他引:3  
江幸福  罗礼智 《昆虫学报》2007,50(11):1173-1180
昆虫黑化是自然界中普遍存在的一种多型现象,也成为揭示物种在自然界中进化与适应的经典范例。昆虫黑化形成的原因与类别多种多样,黑化的遗传调控和分子基础也各不相同。本文根据国外黑化昆虫研究取得的主要进展,结合我国东方粘虫Mythimna separata种群中发生的黑化现象,对昆虫黑化的形成原因、类别、遗传调控、生物学变异以及黑化的分子基础等方面研究现状进行了概述,并对该领域的未来研究热点进行探讨。  相似文献   

7.
昆虫的雌雄二型现象   总被引:5,自引:1,他引:4  
王孟卿  杨定 《昆虫知识》2005,42(6):721-725
对发生雌雄二型现象的昆虫类群、生态因子及进化进行了概括总结;还特别介绍了长足虻科昆虫雌雄二型的相关方面;并简要讨论了雌雄二型与性选择的关系。  相似文献   

8.
王甦  谭晓玲  张帆 《生态学报》2010,30(19):5396-5403
在14、18、22、24℃及30℃下对异色瓢虫Harmonia axyridis(Pallas)的不同同血缘的四龄幼虫自残行为及其对生长发育的影响进行研究。结果表明,异色瓢虫四龄幼虫自残发生概率受环境温度条件影响显著。在22-24℃处理范围内同血缘个体间自残发生概率均显著小于非同血缘个体。自残滞后时间同样受环境温度条件影响显著,且在同一温度条件下同血缘个体间均显著小于非同血缘处理。个体间相互攻击率不受环境温度变化影响,而在高于22℃下受血缘关系影响显著。此外,总受攻击次数在不同温度处理间差异显著。同血缘个体间自残后死亡率随温度增加而减少,均在30%以上。而非同血缘个体间自残后死亡率不受温度变化影响,均在70%以上。自残后残存个体的化蛹率及成虫羽化率均不受环境温度变化及个体间血缘关系的影响,化蛹率除30℃处理外均在90%以上,而在各温度下两血缘处理的羽化率均大于70%。  相似文献   

9.
要想预先知道某种昆虫猖獗发生与否,就必须掌握它的发生规律,也就是必须明确外界环境条件如温度、湿度、光、营养等等与昆虫生活现象的关系。但在自然情况下,外界条件是极其复杂而多样的,并同时作用于昆虫,因此完全籍田间的调查研究工作,常不能明确影响昆虫猖獗发生的主导因子,所以必须在室内利用各种设备,设计多种单一因子的环境条件,进行辅助性的研究工作,方可达到目的。  相似文献   

10.
目前GenBank数据库共收录167种直翅目昆虫全线粒体基因组序列,涉及蝗亚目9个总科22个科99个物种,螽亚目7个总科12个科68个物种。在此基础上,该文分析了直翅目昆虫线粒体基因组的基本特征,概述了线粒体全基因组在直翅目昆虫系统发育研究上的应用;同时基于线粒体全基因组序列重建了直翅目昆虫的系统发育关系。主要结果如下:(1)直翅目昆虫存在8种线粒体基因组排列类型,其中trnK-trnD重排现象仅发生在蝗总科中,trnN-trnS-trnE重排现象仅发生在蟋蟀总科中,trnM-trnI-(-trnQ)重排现象仅发生在拟叶蟲亚科中;(2)直翅目昆虫全线粒体基因组的碱基组成具有明显的AT偏向性;(3)不同的蛋白质编码基因在直翅目昆虫中的进化速率不同;(4)支持直翅目以及螽亚目和蝗亚目的单系性;(5)不支持沙螽总科单系性;(6)支持蝗亚目各总科阶元的单系性,且各总科间的系统发育关系为:(蚤蝼总科+(蚱总科+(?蜢总科+(蜢总科+(长角蝗总科+(牛蝗总科+叶翅蝗总科)+(锥头蝗总科+蝗总科))))))。  相似文献   

11.
Aquaporins: water channel proteins of the cell membrane   总被引:37,自引:0,他引:37  
Aquaporins (AQP) are integral membrane proteins that serve as channels in the transfer of water, and in some cases, small solutes across the membrane. They are conserved in bacteria, plants, and animals. Structural analyses of the molecules have revealed the presence of a pore in the center of each aquaporin molecule. In mammalian cells, more than 10 isoforms (AQP0-AQP10) have been identified so far. They are differentially expressed in many types of cells and tissues in the body. AQP0 is abundant in the lens. AQP1 is found in the blood vessels, kidney proximal tubules, eye, and ear. AQP2 is expressed in the kidney collecting ducts, where it shuttles between the intracellular storage sites and the plasma membrane under the control of antidiuretic hormone (ADH). Mutations of AQP2 result in diabetes insipidus. AQP3 is present in the kidney collecting ducts, epidermis, urinary, respiratory, and digestive tracts. AQP3 in organs other than the kidney may be involved in the supply of water to them. AQP4 is present in the brain astrocytes, eye, ear, skeletal muscle, stomach parietal cells, and kidney collecting ducts. AQP5 is in the secretory cells such as salivary, lacrimal, and sweat glands. AQP5 is also expressed in the ear and eye. AQP6 is localized intracellular vesicles in the kidney collecting duct cells. AQP7 is expressed in the adipocytes, testis, and kidney. AQP8 is expressed in the kidney, testis, and liver. AQP9 is present in the liver and leukocytes. AQP10 is expressed in the intestine. The diverse and characteristic distribution of aquaporins in the body suggests their important and specific roles in each organ.  相似文献   

12.
Lewis spider mite Eotetranychus lewisi (McGregor) is the most important pest in peach orchards, Prunus persica (L.) (Batsch), in North-Central Mexico. In autumn 2003 and spring 2004, two glasshouse experiments were carried out to assess the influence of that mite on the concentration of total soluble sugars and starch in leaves, bark and roots of ‘diamante mejorado’ peach trees. Apical leaves of peach trees were inoculated with three mite densities per leaf: (A) 10–20, (B) 21–40, (C) 41–80; a mite-free control was added. In 2003, at 81 days after infestation (DAI), cumulative mite-days per leaf (CMD) were 153, 1313, 2844 and 4771 in control and treatments (A), (B) and (C), respectively. In the same order, these CMD caused reductions in total soluble sugars (TSS): in leaves, 45, 50 and 61%; in bark, 9, 20 and 33%; in roots, 8, 20 and 26%. Reductions of starch concentration in leaves were 17, 43 and 56%; in bark, 25, 55 and 32%; in roots, 17, 22 and 32%. In 2004, at 77 DAI and 57, 1043, 2426 and 3996 CMD for control and treatments (A), (B) and (C), respectively, resulting reductions of TSS were: in leaves, 3, 7 and 15%; in bark, 0.8, 3 and 5%; in roots, 57, 60 and 78%, whereas reductions in starch concentration were: in leaves, 30, 34 and 44%; in bark, 18, 24 and 41%; in roots, 17, 47 and 48%. The higher reductions in roots found in 2004 are attributed to cumulative injury affecting food reserves.  相似文献   

13.
It is noteworthy that in the rat the early postnatal life is marked by an activation of both the corticostimulating function of the adenohypophysis in neonates of both sexes and of the gonadostimulating function mainly in males. In order to specify if such neuroendocrine variations are temporally correlated with changes in the hypothalamic metabolism of neurotransmitters, the hypothalamic metabolism of serotonin (5 HT), norepinephrine (NE), and dopamine (DA) and the hypothalamic content of neuropeptide Y (NPY) have been investigated in newborn rats of both sexes, delivered at term by cesarean section, as well as changes in the activity of both the hypothalamo-pituitary adrenal axis (HPA) and the hypothalamo-pituitary gonadal axis (HPG). Experimental data suggested that 1) in males a rise in hypothalamic metabolism of 5 HT, NE and DA occurs during the first two hours after delivery, whereas in females, only the metabolism of NE increases. Moreover, the postnatal metabolism of NE was higher in females than in littermate males; 2) NPY content of the hypothalamus, which was at birth significantly higher in males than in females, dropped in the former but not in the latter; 3) in newborn males, an early surge of plasma testosterone occurs, suggesting postnatal activation of the HPG axis; on the other hand, in females, a late and slight increase in plasma estradiol is observed; 4) in early postnatal life, a sex-independent rise in plasma ACTH and adrenal and plasma corticosterone levels suggest a comparable activation of the HPA axis in newborns of both sexes. In conclusion, the early postnatal activation of the corticostimulating function in neonates of both sexes and that of the gonadostimulating function, mainly in males, could be temporally correlated with a rise in the hypothalamic metabolism of two neurotransmitters, 5 HT and NE, and of NPY content. According to our data, a sex-dependent metabolsim of neurotransmitters in the hypothalamus is already apparent in early postnatal life.  相似文献   

14.
The spined soldier bug, Podisus maculiventris, is a generalist predator of insects and has been used in biological control. However, information on the digestion of food in this insect is lacking. Therefore, we have studied the digestive system in P. maculiventris, and further characterized carbohydrases in the digestive tract. The midgut of all developmental stages was composed of anterior, median, and posterior regions. The volumes of the anterior midgut decreased and the median midgut increased in older instars and adults, suggesting a more important role of the median midgut in food digestion. However, carbohydrase activities were predominant in the anterior midgut. In comparing the specific activity of carbohydrases, α‐amylase activity was more in the salivary glands (with two distinct activity bands in zymograms), and glucosidase and galactosidase activities were more in the midgut. Salivary α‐amylases were detected in the prey hemolymph, demonstrating the role of these enzymes in extra‐oral digestion. However, the catalytic efficiency of midgut α‐amylase activity was approximately twofold more than that of the salivary gland enzymes, and was more efficient in digesting soluble starch than glycogen. Midgut α‐amylases were developmentally regulated, as one isoform was found in first instar compared to three isoforms in fifth instar nymphs. Starvation significantly affected carbohydrase activities in the midgut, and acarbose inhibited α‐amylases from both the salivary glands and midgut in vitro and in vivo. The structural diversity and developmental regulation of carbohydrases in the digestive system of P. maculiventris demonstrate the importance of these enzymes in extra‐oral and intra‐tract digestion, and may explain the capability of the hemipteran to utilize diverse food sources.  相似文献   

15.
We present an updated worldwide phylogenetic classification of Poaceae with 11 783 species in 12 subfamilies, 7 supertribes, 54 tribes, 5 super subtribes, 109 subtribes, and 789 accepted genera. The subfamilies (in descending order based on the number of species) are Pooideae with 4126 species in 219 genera, 15 tribes, and 34 subtribes; Panicoideae with 3325 species in 242 genera, 14 tribes, and 24 subtribes; Bambusoideae with 1698 species in 136 genera, 3 tribes, and 19 subtribes; Chloridoideae with 1603 species in 121 genera, 5 tribes, and 30 subtribes; Aristidoideae with 367 species in three generaand one tribe; Danthonioideae with 292 species in 19 generaand 1 tribe; Micrairoideae with 192 species in nine generaand three tribes; Oryzoideae with 117 species in 19 genera, 4 tribes, and 2 subtribes; Arundinoideae with 36 species in 14 genera and 3 tribes; Pharoideae with 12 species in three generaand one tribe; Puelioideae with 11 species in two generaand two tribes; and the Anomochlooideae with four species in two generaand two tribes. Two new tribes and 22 new or resurrected subtribes are recognized. Forty-five new (28) and resurrected (17) genera are accepted, and 24 previously accepted genera are placed in synonymy. We also provide an updated list of all accepted genera including common synonyms, genus authors, number of species in each accepted genus, and subfamily affiliation. We propose Locajonoa, a new name and rank with a new combination, L. coerulescens. The following seven new combinations are made in Lorenzochloa: L. bomanii, L. henrardiana, L. mucronata, L. obtusa, L. orurensis, L. rigidiseta, and L. venusta.  相似文献   

16.
Al adjuvants are used in vaccines to increase the immune response. NTPDase and AChE play a pivotal role and act in the regulation of the immune system. The effect of Al exposure in vitro and in vivo on NTPDase and AChE activities in the lymphocytes of rats was determined. In vitro, ATP hydrolysis was decreased by 20.4% and 17.3% and ADP hydrolysis was decreased by 36.5% and 34.8%, in groups D and E, respectively, when compared to the control. AChE activity was increased by 157.3%, 152.5%, 74.7% and 90.8% in groups B, C, D, and E, respectively, when compared to the control. In vivo, ATP hydrolysis was increased by 85% and 86% and ADP hydrolysis was increased by 104.2% and 74%, in Al plus citrate and Al groups, respectively, when compared to the control. AChE activity was increased by 50.7% in Al plus citrate and by 28.6% in Al groups, when compared to the control. Our results show that Al exposure both in vitro and in vivo altered NTPDase and AChE activities in lymphocytes. These results may demonstrate the ability of Al to elicit the immune system, where NTPDase and AChE activities can act as purinergic and cholinergic markers in lymphocytes.  相似文献   

17.
随着我国小动物诊疗行业与国际兽医临床技术的接轨,国内的兽医学科向专科方向发展,小动物心血管疾病在老年动物呈现出越来越高发的迹象,临床兽医在心血管疾病的研究也越来越深入,也更多的借鉴了人类心脏病学的诊疗检查手段,通过将犬猫心血管疾病特点与人类相比较,发现两者之异同,希望能籍此指导犬猫心血管疾病诊疗,满足动物主人的需求,维护动物健康,缓解给动物主人所带来的焦虑,体现兽医在维护人类身心健康的作用。  相似文献   

18.
苏春田  唐建生  梁彬 《生态学杂志》2012,31(8):2131-2136
采用雨量器、滤膜法、CO2气体监测管法、标准试片对湘西洛塔不同生态系统降雨量、泥沙量、土壤CO2浓度、溶蚀速度进行了研究。结果表明:森林生态系统降雨量高于灌丛生态系统,观测第一年高6.84mm,第二年高218.08mm,且时间趋向均匀;灌丛生态系统水土流失严重,其泥沙含量是森林生态系统的1.53倍,土壤侵蚀为强度,而森林生态系统为微度;不同深度土壤CO2浓度在森林和灌丛生态系统中具有相同的变化趋势,在春季、秋季、冬季随土层加深而增大,在夏季,随土层加深先减少后增大,但季节变化动态略有差异,森林生态系统不同深度、不同季节土壤CO2浓度均大于灌丛生态系统;从全年土壤CO2浓度对比来看,10、20、40cm处,森林生态系统分别是灌丛生态系统的1.66、1.59和1.90倍;不同深度上,溶蚀速度在森林和灌丛生态系统具有相同的变化趋势,15cm处均大于地面,从同一深度来看,森林生态系统溶蚀速度均大于灌丛生态系统,地面、15cm处溶蚀速度分别是灌丛生态系统的1.11倍、2.57倍,说明森林生态系统具有较好的岩溶效应。  相似文献   

19.
Granulin epithelin precursor (GEP) is a new growth factor that functions in brain development, chondrogenesis, tissue regeneration, tumorigenesis, and inflammation. The goal of this study was to study whether GEP was critical for odontogenesis and amelogenesis both in vivo and in vitro. The in situ hybridization and immunohistochemistry data showed that GEP was expressed in both odontoblast and ameloblast cells postnatally. Knockdown of GEP by crossing U6-ploxPneo-GEP and Sox2-Cre transgenic mice led to a reduction of dentin thickness, an increase in predentin thickness, and a reduction in mineral content in enamel. The in vitro application of recombinant GEP up-regulated molecular markers important for odontogenesis (DMP1, DSPP, and ALP) and amelogenesis (ameloblastin, amelogenin and enamelin). In conclusion, both the in vivo and the in vivo data support an important role of GEP in tooth formation during postnatal development.  相似文献   

20.
Digestive enzyme distribution and activity in the digestive tracts of the rabbitfish, Siganus canaliculatus and the sea bass, Lates calcarifer were studied. Quantitative determinations of digestive enzymes in the guts of both fishes showed that they were capable of digesting carbohydrates and proteins in their diet. The carbohydrases, amylase, laminarinase, maltase, sucrase and trehalase were detected in the rabbitfish; their activities being mainly in the stomach, intestine and pyloriccaeca. Amylase, maltase, trehalase and chitinase activities were recorded in the gut of the sea bass, primarily in the intestine and the pyloriccaeca. Their activities were significantly lower than those in the rabbitfish. Proteases (pepsin, chymotrypsin, elastase, leucine aminopeptidase and trypsin) were found in both the rabbitfish and the sea bass. Pepsin activity however, was higher in the sea bass; while trypsin and chymotrypsin activities were higher in the rabbitfish. The activities of the various digestive enzymes in both fishes are discussed in relation to their feeding habits.  相似文献   

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