The author has collected a great deal of valuable materials about frog visual behavior . the visual characteristic of amphibian such as frog has been studied which includes the structure of frogeyes and the retina ganglion cell 本文在收集了有关青蛙视觉大量宝贵资料后,首先分析了青蛙等两栖类动物的视觉特点,其中包括蛙眼的结构,以及在视觉处理初期担任重要角色的视网膜神经元细胞的反应特性。
They are mostly secretive in nature and are only active when they are not readily observed , they are much less known to most of us than other animals like birds and mammals , and are sometimes even misunderstood . they are a mysterious group of animals called amphibians , or more commonly known as frogs and salamanders 它们生性羞怯,行动诡秘,通常在难以观察的时份出没,因此远远不及雀鸟或哺乳类等动物为人熟悉,有时更会令人对物们产生误解。这群神秘的动物名为两栖类动物,亦常称为蛙类或蝾螈。
3 the comparison of mitochondrial genomes and phylogentic relationships of amphibian there still is a lack of consensus regarding living amphibian phylogenetic relationships . the most widely accepted hypothesis , based on morphological data , supports the monophyletic origin in the late paleozoic ( 300 mya ) of the three living orders in the class amphibia and a sister - group relationship between caudata and anura ( the batrachia hypothesis ) to the exclusion of the gymnophiona 3两栖类动物的线粒体基因组结构比较和系统发生关系现存两栖类的三个目的系统发生关系仍然没有统一意见,最广泛被接受的假说,是建立在形态学证据基础上,支持现生的两栖类三个目在古生代后期( 300mya )单系起源,并且无尾类和有尾类为姐妹群关系(蛙类假说) 。
The complete nucleotide sequence of the mitochondrial genome of f . limnocharis was detailedly compared with those of 5 other amphibians . the nucleotide sequences of 22 trna encoded by 6 amphibians mitochondrial genomes were combined and aligned to the homologous sequences of the 11 veterbrate taxa . using teleosts as outgroup , the phylogenetic analyses results show that mp , nj and ml trees all strongly support the monophyly of living amphibians with respect to other living tetrapods and favor a sister group relationship for caecilians and salamanders 我们在测定了泽蛙线粒体全基因组序列的基础上,与已知其它的5种两栖类进行详细的比较分析,同时选择了11种高等脊椎动物的线粒体全基因序列,以硬骨鱼类做外群,用22个trna基因合并数据进行系统发生重建分析,结果表明mp 、 nj和ml树都强力地支持现生两栖类动物为单系群并且蝾螈类和蚓螈类为姐妹群关系(自引导值分别为92 、 99 、 100 ) 。
Several climatic belts of the world are represented in the grand canyon region which supports such diverse plant life as the yucca of the dry desert to the blue spruce of the coniferous forest . animal life in the grand canyon is by no means scarce and includes about 89 mammal , 355 bird , 17 fish , 47 reptile and 9 amphibian species 大峡谷拥有不同的气候特徵,由酷热的沙漠气候到热带亚热带甚至温带的气候亦可在大峡谷找到,它并不是一个荒凉死寂的世界,不少动植物均生活于其中,计有89种哺乳动物355种鸟类17种鱼类47种爬虫类和9种两栖类动物。