()、纵纹腹小()和红隼视器的比较形态学研究

为了探讨猛禽视器结构与生活习性的关系,用光镜和扫描电镜观察、测量并统计了、纵纹腹小和红隼视网膜各层的厚度,三个核层的胞核层数和视细胞密度.视网膜外核层、内核层和节细胞层胞核的平均层数在依次为2.6、7.6和0.4层;在小为3.0、11.4和1.9层;红隼为1.6、14.6和1.7层.视网膜中央区视锥细胞密度(±SD)在为190 117±27 304个/mm2,小为202 122±49 542个/mm2,红隼为234 039±44 916个/mm2.视网膜周围区视杆细胞的密度在为190 422±26 595个/mm2,小为165 800±26 408个/mm2,红隼为178 015±40 165个/mm2.红隼视网膜周围区还有视锥细胞分布,其密度为22 082±9 864个/mm2.结果表明,视器的结构为夜行性特征,而小有趋于晨昏活动的特点,红隼为典型的昼行性视觉特征.3种猛禽栖息于同一生态环境内,视器的结构差异显示出其时间活动格局上的差异.     

野生朱()的新繁殖地

朱()(Nipponia nippon)是世界极危物种(CR),现只有一个野生种群,数量60只左右,生活在我国陕西省洋县境内,分布范围极其狭小.     

朱()营巢生境的分析

在陕西省洋县境内调查了13个朱()巢的生境,分12个属性记载,并做定量统计分析.由模糊聚类分析法把样点分成了近湿地类型区和远湿地类型区;由主分量分析证明,树型高大、隐蔽度和周围植被条件好、离居民点较近的马尾松或栓皮栎树是朱()营巢的优选条件.     

卵胎生硬骨鱼褐菖()卵巢的周期发育研究

经组织学观察表明,褐菖()(Sebastiscus marmoratus)的卵巢由卵巢壁、卵巢绒毛和卵巢腔构成.卵巢壁的肌层较厚,卵巢上皮具分泌功能.卵巢绒毛位于卵巢腔中,呈树枝状.在卵巢绒毛上分布着滤泡.滤泡由卵母细胞和滤泡膜构成.滤泡膜包括内层的颗粒层和外层的鞘膜层.鞘膜层上有丰富的毛细血管.滤泡靠滤泡柄悬挂在卵巢绒毛上.卵巢发育分7个时期.成熟卵排放在卵巢腔中受精.胚胎浸置在卵巢液中发育.卵巢发育、卵巢成熟系数和卵巢壁厚度随季节呈年周期变化.     

外源性褪黑激素对中缅树()适应性产热特征的影响

注射外源性褪黑激素后,中缅树Ｑｕ体温明显降低,静止代谢率和非颤拦性产热显著增加,并随蝗延长增加的赵多,注射褪黑激素不能影响肝脏的褐色脂肪组织的重量,但两者线粒体蛋白含量显著增加、线粒体呼吸和细胞色素Ｃ氧化酶活性增加;褐色脂肪组织的α磷酸甘油氧化酶和Ｔ４５’－脱碘酶活性显著增加;血清Ｔ３浓度显著上升,Ｔ４浓度显著降低。结果表明,松果体褪黑激素参与了中缅树Ｑｕ的适应性产热调节。     

光周期和温度对中缅树()产热能力的影响

低温短光照诱导中缅树()体重增加、体温降低、产热能力增强,静止代谢率增加的速度和比例高于非颤抖性产热;低温短光照刺激肝脏线粒体蛋白质量、线粒体氧化能力和细胞色素C氧化酶活性显著增加;短光照也刺激褐色脂肪组织总蛋白和线粒体蛋白量、线粒体状态IV呼吸、细胞色素C氧化酶、α-磷酸甘油氧化酶及T45'-脱碘酶活性显著提高.低温和短光照促使血清T3浓度增加、T4浓度不变.结果表明,中缅树()的适应性产热特征不仅受到低温的显著影响,而且光周期也参与了适应性产热的调节.     

日本鬼()背鳍棘毒腺中Ⅰ、Ⅱ型毒腺细胞关系的探讨

日本鬼()背鳍棘毒腺中有两种类型毒腺细胞--Ⅰ型细胞和Ⅱ型细胞.两种细胞结构明显不同.本文用形态学方法探讨Ⅰ型与Ⅱ型细胞的关系.结果表明:毒腺组织中Ⅰ型细胞光镜下有的胞质内可见浅染点样结构,并且在不同的细胞内其浅染点状结构的多少有差异;电镜下Ⅰ型细胞膜结构差异较大,有的Ⅰ型细胞的脂质双层膜性结构清楚;有的细胞膜外侧可见膜包小泡;有的细胞内侧面也见小泡形成、融合,使脂质双层膜间隙变宽,其内可见膜包样物质,其电子密度中等或较高,结构类似于Ⅱ型细胞的囊泡样物质.不同的Ⅱ型细胞其胞质内颗粒大小及电子密度不一,囊泡状物多少也不一.含较小而密集颗粒的Ⅱ型细胞胞膜的脂质双层膜的外侧面较规则,与Ⅰ型细胞相似;脂质双层膜的内侧面出现许多扩张的大囊泡,其内含物电子密度高或中等,与胞质内含的颗粒状物质相同;位于扩张的囊泡与胞膜之间的胞质结构有的与I型细胞的胞质内的某些结构相似.含大而稀疏颗粒的Ⅱ型细胞其颗粒数量少、电子密度差异大,并且囊泡样物质增多.推测Ⅱ型细胞可能由Ⅰ型细胞转化而来.     

二叠纪新小纺锤()模式种Neofusulinella lantenoisi Deprat,1913在云南保山的发现

Ｎｅｏｆｕｓｕｌｉｎｅｌｌａ Ｄｅｐｒａｔ,１９１２是一个有效属,但其模式标本遗失,最早发表的共模切面不正,加之手绘图影不清楚,长期未能准确地把握其属征。除原作者（Ｄｅｐｒａｔ,１９１３）首次记述的模式种（Ｎ．ｌａｎｔｅｎｏｉｓｉ Ｄｅｐｒａｔ－Ｔｈｏｍｐｓｏｎ,１９３４,ｐ．２９２事后指定）以及Ｔｈｏｍｐｓｏｎ和Ｆｏｓｔｅｒ（１９３７）和Ｐｉｔａｋｐａｉｖａｎ（１９６５）所记述的同种外,其余的有     

Do Antarctic lichens modify microclimate and facilitate vascular plants in the maritime Antarctic? A comment to Molina‐Montenegro et al. ()

A recent article published by Molina‐Montenegro et al. (Journal of Vegetation Science24: 463) examines the association of Antarctic native plant and lichen species to the lichen Usnea antarctica on Fildes Peninsula, King George Island, maritime Antarctica. The authors report that on two sites, five out of 13 and four out of 11 species of lichens and mosses were spatially associated with U. antarctica, suggesting positive interactions between them. Although Deschampsia antarctica does not grow naturally associated with U. antarctica, Molina‐Montenegro et al. carried out a transplantation experiment to demonstrate that the macrolichen acts as a nurse plant, improving the survival of the grass. Serious conceptual and methodological discrepancies emerge from a critical evaluation of this study, challenging their conclusions. First, we suspect that the author confused some lichen taxa, and we also disagree with macrolichens being treated as cushion plants, because rootless, poikilohydric and poikilothermic thallophytes such as lichens are unable to create a stable, enclave‐like microhabitat as vascular cushion plants do. Indeed, a critical evaluation of some of the micro‐environmental parameters measured indicates that there are no biologically meaningful differences between the U. antarctica thalli and surrounding open areas. Second, the lack of consideration of the life history of the species under study leads to confusion when (a) referring to the succession sequence of species that colonize the studied area and (b) interpreting the putative distribution patterns promoted by Usnea versus the substrate preferences of associated species. Third, the authors intend to demonstrate experimentally that Usnea can facilitate the survival of D. antarctica plants, transplanting adult plants and not seedlings between the lichen thalli, and it is not clear how the grass was planted – between or within the lichens – as at both experimental sites the lichens grow on stones or rocks. Facilitative interactions are present in the Antarctic and may play a pivotal role in the structure and functioning of the fragile Antarctic ecosystems. However, more rigorous and well‐planned research is needed to assess its presence, importance and involved mechanisms.