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1.
黄颡鱼头骨的研究   总被引:4,自引:0,他引:4  
黄颡鱼头骨共有126块,无顶骨、后耳骨和下鳃盖骨,有续软骨存在.犁骨、前颌骨、齿骨上都具铺石状牙齿,上颌骨、腭骨不具齿而成棒状小骨支持触须.舌颌骨、方骨、中翼骨、外翼骨发育良好.前鳃盖骨失去鳃盖作用而参与悬器的形成.  相似文献   

2.
黄颡鱼是广布于我国各江河湖泊的一种习见小型经济鱼类,生活水流底层。其头骨共有126块;无顶骨、后耳骨和下鳃盖骨,有续软骨存在。犁骨、前颌骨、齿骨上都具铺石状牙齿;上颌骨、腭骨不具齿而异常特化成棒状小骨以支持触须。舌颌骨、方骨、中翼骨、外翼骨发育良好。前鳃盖骨失去鳃盖作用而参与悬器的形成。  相似文献   

3.
本文对瓦氏黄颡头骨形态作了详细描述,并对鲶形目续骨的退化和前鳃盖骨功能的转变进行了讨论。通过对鲿科、鲶科、鮡科、胡子鲶科和鲤科共8种鱼类头骨的比较观察,发现鲶类头骨的又一显著特征,即上枕骨上有一对三叉神经叉脊支神经孔。 瓦氏黄颡的头骨由125块(含软骨)组成,其中脑颅37块,咽颅86块(颌弓20,舌弓37,鳃弓31)。其头骨的主要特点可归纳如下: (1)无顶骨、后耳骨和下鳃盖骨; (2)腭骨呈棒状,后端游离,前端与上颌骨关节;上颌骨退化成短棍状以支持触须。 (3)上枕骨具发达的柄状上枕棘及腹脊,以及一对三叉神经叉脊支神经孔。 (4)前囟和后囟均存在,且较宽,表明其在进化上的原始性; (5)由泪骨、侧筛骨、筛骨、鼻骨和前颌骨构成的框架保护其发达的鼻囊; (6)由4对围眶骨和侧筛骨、额骨保护其较发达的眼; (7)前鳃盖骨与舌颌骨、方骨紧密关节,间鳃盖骨紧贴在上舌骨的外面,均参与悬器的形成; (8)鳃弓骨化不全,仅骨化出2枚基鳃骨、2对下鳃骨;相当于基一下鳃骨区域的其余部分终生保留为软骨; (9)具软骨性续骨。  相似文献   

4.
对沟鲹骨骼系统的特征进行了观察,并比较其与蓝圆鲹、美长吻鲹、游鳍叶鲹及镰鳍裸胸鲹等4种鲹科鱼类的差别,结果表明,它们脑颅上的上筛骨、侧筛骨、犁骨、额骨、眶下骨、蝶耳骨、翼耳骨和上耳骨等,咽颅上的前上颌骨、腭骨、舌颌骨、尾舌骨、鳃盖骨和上枕骨等;肩带上的主后颞骨、后颞骨、上匙骨、后匙骨等均有明显的差异,其中某些特征可能是...  相似文献   

5.
这篇文章是对长吻(鱼危)骨骼的描述. 长吻(鱼危)是我国的一种经济鱼类.它们生活在河流的底层,其骨骼系统比鲤科鱼类有较大的变形. 颅骨有长的额骨形成船形结构.有后额骨,但无顶骨、续骨、下鳃盖骨及间鳃盖骨.前鳃盖骨缩窄为一斜的赘骨向内延伸,并连接成悬器的侧支架.上枕骨的长柄被坚固的关节在背鳍的第一根鳍条上. 梨骨、前颌骨和齿骨上都有一系列的牙齿,但上颌骨不具齿并异常特化为一小骨以支持触须. 舌颌骨、方骨和中翼骨发育良好,三叉形的(?)骨游离在梨骨的下面,围眼骨系缺乏.这些都是鲶形目的特点. 脊柱由40个脊椎组成.也许目的在于支持重大的颅骨,第一到第五个脊椎愈合成一复合的脊椎被连接在基枕骨上. 肩带坚实由上匙骨.匙骨.肩胛骨和鸟啄骨组成,有两块基鳍骨和11根鳍条在肩带的后面. 腰带只由一块基翼骨(盆骨)组成,有六根鳍条在基翼骨后面,  相似文献   

6.
常规方法制备大头狗母鱼骨骼标本,记录观测结果并绘图.其主要形态特征为:缺眶上骨,眶下骨7块,第1块特大,第4~7块呈不规则的颗粒状.上筛骨短宽.具眶蝶骨.前耳骨发达,向外鼓出明显.有下颞窝.前颌骨和齿骨具发达的锥形齿.腭骨有锥形齿2列,基鳃骨也有锥形齿.第2~4咽鳃骨和下咽骨有齿.主后颞骨和后颞骨有小齿.腰带骨基部愈合.  相似文献   

7.
为揭示骨骼系统在石斑鱼类的物种鉴定和系统进化关系研究中的应用潜力,本研究采用传统的骨骼系统比较法分析南海北部近海的尾纹九棘鲈(Cephalopholis urodeta)、鸢鮨(Triso dermopterus)、青石斑鱼(Epinephelus awoara)、拟青石斑鱼(E.fasciatomaculosus)和断带石斑鱼(E.craigi)等3属5种石斑鱼类的骨骼特征。结果显示,在分析的15种骨片中,中筛骨、额骨、翼耳骨、上枕骨、前鳃盖骨、上匙骨、尾舌骨等7种骨片显示出明显的属特征。尾纹九棘鲈的骨片形态结构总体较简单,而鸢鮨和石斑鱼属(Epinephelus)石斑鱼的骨片形态结构更为分化且复杂,并且二者具有相似类型的骨片数最多(8种)。有10种骨片可将断带石斑鱼与青石斑鱼、拟青石斑鱼有效区分,其中翼蝶骨、蝶耳骨、翼耳骨、上枕骨和前鳃盖骨等5种骨片在断带石斑鱼中显示出显著的种类特性。青石斑鱼和拟青石斑鱼的主要骨骼差异在于额骨、前鳃盖骨、上匙骨。本研究的结果支持了鸢鮨属(Triso)与石斑鱼属有较为密切的亲缘关系以及九棘鲈属(Cephalopholis)是较石斑鱼属更为原始的一个独...  相似文献   

8.
观察了侧条光唇鱼鳞片、脊椎骨、主鳃盖骨和耳石的年轮特征.鳞片分区明显,环片清晰常呈U型,年轮主要为疏密型,切割型较少见,偶见副轮;脊椎骨为明暗交替的同心环纹,近中心处年轮不清晰;主鳃盖骨为明暗交替的L型环带平行分布,L型的拐角处或其附近较明显;耳石年轮围绕中心核呈弧状排列,轮纹特征在后区清晰.鳞片为侧条光唇鱼年龄鉴定材料,脊椎骨、主鳃盖骨和耳石可用于辅助鉴定.  相似文献   

9.
本文整理和详细观察了鸟鳢骨骼系统的结构特征。据研究,乌鳢脑颅的鳃弓和颌弓上有圆锥齿和绒毛状细齿。下颞窝和后颞窝发达。这些构造都与其捕食习性相适应。乌鳢第一鳃弓的咽鳃骨,舌弓的舌颌骨构成鳃上器官。脊椎骨的数目幼鱼和成鱼有所区别。  相似文献   

10.
罗源湾及九龙江口美肩鳃鳚仔、稚鱼的新记录   总被引:1,自引:0,他引:1  
研究了罗源湾和九龙江口美肩锶鲥仔、稚鱼的形态特征,时空分布及其与环境的关系,美肩锶鲥不仅分布在黄海和渤海,南海和东海也有分布。仔稚鱼的主要特征:眼大、吻短、稍突出、头高、体中等延长,左右侧肩,头顶包一骨质冠,头冠左右两侧及左右眼眶上有骨嵴,前锶盖骨隅角具一强棘,以上构造都着生小刺,前鳃盖骨后缘有4枚小棘突,腹囊大,背面具黑色素点,肌节37~45(8-12 28-32),背鳍一个,延长,胸鳍大,腹鳍喉位,背、臀鳍的两支鳍骨之间有尖三角形骨片。  相似文献   

11.
青石爬鮡头骨形态的观察   总被引:1,自引:0,他引:1  
对青石爬鮡的头骨形态作了描述.结果表明,其头骨不仅具有鲶形目鱼类的共有特征,而且具有一些高度特化的特征,如头骨极为平扁,腭骨、颌骨特化并高度发达,鳃弓的基-下鳃区骨化程度很低,大部分为结缔组织.这些特化是与其山溪激流生活相适应的.  相似文献   

12.
The development of computer tomography and image processing has made it possible to establish virtual 3D reconstruction and non-invasive dissection of fossil specimens. We used these methods to reconstruct a virtual 3D skull of a Pleistocene cheetah skull from the Tuozi cave, Tangshan, Nanjing, and virtually dissected it for anatomic studies, and measured the volumes of different parts of the endocranium. The endocranium of the cheetah skull has showed that its frontal sinus is beehive-like, the frontal lobe of cerebra is relatively large but the temporal lobe is relatively small, its cerebral sulcus and gyrus are more complicated than those of the domestic cat, similar to those of the domestic dog, but simpler than those of giant panda, pig, cattle and horse. The technology of virtual 3D reconstruction and non-invasive dissection of fossil specimens can extend the morphological study from the exterior to the interior, and it can also help to study fragile specimens and virtually backup rare and precious specimens.  相似文献   

13.
The development of computer tomography and image processing has made it possible to establish virtual 3D reconstruction and non-invasive dissection of fossil specimens. We used these methods to reconstruct a virtual 3D skull of a Pleistocene cheetah skull from the Tuozi cave, Tangshan, Nanjing, and virtually dissected it for anatomic studies, and measured the volumes of different parts of the endocranium. The endocranium of the cheetah skull has showed that its frontal sinus is beehive-like, the frontal lobe of cerebra is relatively large but the temporal lobe is relatively small, its cerebral sulcus and gyrus are more complicated than those of the domestic cat, similar to those of the domestic dog, but simpler than those of giant panda, pig, cattle and horse. The technology of virtual 3D reconstruction and non-invasive dissection of fossil specimens can extend the morphological study from the exterior to the interior, and it can also help to study fragile specimens and virtually backup rare and precious specimens.  相似文献   

14.
应用乙酰胆碱酯酶定位方法对东方簇盾吸虫(Lophotaspis orientalis Faust and Tang,1936)成虫的神经系统进行了研究.成虫的神经系统十分复杂,包括中枢神经结、脑神经联合、纵行的神经干、横向的神经连合.中枢神经结位于咽前部两侧,有1粗大的脑神经联合连接.在脑神经联合的下方有1个小的环形的结构.中枢神经结向前发出1对前背神经干和1对前侧神经干,这2对神经干向前的分支汇入围口腔的神经环.中枢神经结向后发出1对后背神经干和1对后腹神经干.后背神经干之间有横向的神经相连,在体末端与后腹神经干相汇合.后腹神经干最为粗大,并在虫体末端汇合,它在腹盘处有2对分支进入腹盘,前1对与腹盘边缘神经相连,后1对贯穿腹盘,其分支构成腹吸盘内复杂的神经网.腹吸盘的指状突起内也有神经分支.  相似文献   

15.
Since the musk deer distributed in the Dabie Mountains, Anhui was defined asMoschus moschiferus anhuiensis, its status has been disputed based on researches of morphology and ecology. This study further probed into its taxonomic status with principal components analysis (PCA) on skull measurements and mtDNA cytochrome b sequences (367 bp) analysis so as to clear its status. It is concluded that the figure and skull in Anhui musk deer are different from other species, and DNA divergence between it and other species is 6.24%–7.90%, which belongs to inter-specific difference. Thus, the study defines this musk deer as one distinct species,Moschus anhuiensis (Wang, Huet al.)  相似文献   

16.
李晖      杨绍辉      张军      纪志飞      王士铎 《华侨大学学报(自然科学版)》2023,(1):60-70
以链家房产交易平台和安居客房产交易平台的上海市二手住宅为研究样本,结合OpenStreetMap(OSM)提供的城市路网数据及高德地图提供的兴趣点(POI)等多源数据,利用空间句法测算路网空间结构的选择度和整合度.基于空间自回归模型、地理加权回归模型等空间计量估计方法,研究城市路网空间结构影响住宅价格的效果及机制.研究结果表明:城市路网空间结构是影响住宅价格的重要的区位因素,考虑空间相关性是必要的;与市中心住宅价格相比,郊区住宅价格对路网空间结构的依赖程度更强.  相似文献   

17.
Neural organization for the long-term memory of paired associates   总被引:21,自引:0,他引:21  
K Sakai  Y Miyashita 《Nature》1991,354(6349):152-155
Most of our long-term memories of episodes or objects are organized so that we can retrieve them by association. Clinical neuropsychologists assess human memory by the paired-associate learning test, in which a series of paired words or figures is presented and the subject is then asked to retrieve the other pair member associated with each cue. Patients with lesions of the temporal lobe show marked impairment in this test. In our study, we trained monkeys in a pair-association task using a set of computer-generated paired patterns. We found two types of task-related neurons in the anterior temporal cortex. One type selectively responded to both pictures of the paired associates. The other type, which had the strongest response to one picture during the cue presentation, exhibited increasing activity during the delay period when the associate of that picture was used as a cue. These results provide new evidence that single neurons acquire selectivity for visual patterns through associative learning. They also indicate neural mechanisms for storage and retrieval in the long-term memory of paired associates.  相似文献   

18.
要保证牙轮钻头在高转速下的使用寿命,关键在于轴承,严重的粘着磨损即胶合,是牙轮钻头滑动轴承主要的失效形式,本文针对一系列可供选择的滑动轴承材料,以正交试验讨论了其相互配磨的摩擦系数与磨损量,为选择和配用滑动轴承材料提供了依据,试验分析知,经CVO处理的硬质合金与硬质合金配磨时其摩擦系数较小,配磨副之间的磨损量最小,是理想的硬对硬滑动轴承材料.若为提高抗胶合性,则应选铅基巴氏合金等等.  相似文献   

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