大泷六线鱼仔稚鱼头部骨骼发育观察

采用软骨-硬骨双染色方法, 对大泷六线鱼仔稚鱼头部骨骼的发育过程进行详细观察与分析。结果显示: 大泷六线鱼初孵仔鱼头部已存在迈克尔氏软骨、腭方骨、舌棒骨和第一基舌软骨等骨骼元件; 当仔鱼4 DPH时, 第二基鳃软骨出现在第一基鳃软骨后端, 缘带向后延伸, 且软骨桥出现, 将头盖骨分为前卤和后卤; 9 DPH时, 3对鳃下骨, 第五对角腮骨可见; 13 DPH时, 迈克尔氏软骨背中部突, 4对鳃上骨、鼻骨、中筛板和侧筛板相继出现; 16—21 DPH时, 基舌骨出现在第一基鳃软骨前方; 23 DPH时, 齿骨开始骨化; 26 DPH时, 前颌骨和上颌骨开始骨化; 至35 DPH时, 前颌骨和上颌骨完成骨化; 50 DPH时, 副蝶骨、前鳃盖骨、缘带、后翼骨、鼻骨和续骨完成骨化; 60 DPH时, 大泷六线鱼头部骨骼, 除舌棒骨外, 基本骨化完成。研究摸清了大泷六线鱼仔稚鱼头部骨骼不同骨元件的发育时序, 阐释了头部骨骼的发育规律及其特殊性, 为大泷六线鱼早期骨骼功能发育研究及头部骨骼畸形鉴定提供了科学依据。     

五种蝌蚪口器及舌鳃骨的结构比较

采用体视显微镜和骨骼双染色法对5种不同栖息环境的无尾两栖动物蝌蚪的口器和舌鳃骨的形态结构特征进行了观察。5种蝌蚪口器由唇齿行、唇乳突和角质颌等组成。舌鳃骨是由关联骨Ⅰ、关联骨Ⅱ、角舌骨、舌鳃骨盘和角鳃骨等骨骼组成。蝌蚪的梅氏软骨若较发达,其摄食方式可能为刮食;蝌蚪的舌鳃骨发达,其摄食方式则可能为滤食。角质颌、唇齿以及角鳃骨上鳃耙的出现显著增强了蝌蚪主动摄食能力和对食物与非食物的主动选择性。     

黄鳝舌骨及生长的研究

本文对黄鳝的舌骨结构及生长特点,年龄标志及鉴定,体长和体生地生长与年龄的关系等作了研究。舌骨主要由基舌骨,尾舌骨,下舌骨,角舌骨,上舌骨,间舌骨和鳃条骨组成。基舌骨和尾舌骨完全愈合;上舌骨,角舌骨,上舌骨,间舌骨以犬齿形相为一整体合称“侧舌骨”,且左右对称。     

（鱼句）亚科花（鱼骨）型鱼类骨骼系统的比较

对我国花型Hemibarbuspattern鱼类作了骨骼系统比较,结果表明,此类型鱼类脑颅较长,副蝶骨平直或稍弯曲,眶蝶骨腹纵嵴发达(铜鱼Coreius septentrionalis例外),下颞窝和咽突中等大,基枕骨后突发达;脑颅中的上筛骨的后突、侧筛骨的外筛突,蝶耳骨的外突、上耳骨的后突、围眶骨和后颞窝等均有明显的差异;咽颅中的舌颌骨、尾舌骨、鳃盖骨和下咽齿的列数等又有显著的区别;附肢骨骼中的腰带骨、脊椎骨中的复合神经骨和第4椎骨腹侧的悬器等也有不同之处。据此,这些差异和区别可作为属间或种间的分类依据。     

虻科成虫雌性尾器亚生殖板的研究

应用亚生殖板细微结构的鉴别方法,研究了虻科20种雌性成虫雌性尾器的亚生殖板。结果表明:虻科雌性成虫不同种其尾器亚生殖板整体大小,颜色,有无骨化现象、骨化部位及骨化程度,端缘、基缘凹陷深浅及宽窄,侧突位置、大小,基角大小及形状,毛和鬃的有无、着生位置及多少,皱褶的有无及位置等特征均有变化。虻科成虫雌性尾器亚生殖板的细微结构有种间鉴别的特异性。     

蒙原羚亚成体外部形态及消化道若干指标的测量分析

对在内蒙古自治区新巴尔虎右旗猎捕到的蒙原羚(Procapragutturosa)亚成体的外部形态及消化道若干指标进行了测量及分析,结果表明,蒙原羚亚成体的体重平均为27.47kg,体长平均为105.37cm,尾长平均为10.94cm,肩高平均为56.55cm。蒙原羚亚成体胃(含胃容物)的总重为5.26kg,占体重的19.15%;瘤胃(含胃容物)重(平均3.81kg)占胃总重的72.43%;肠道总长为2708.86cm,是体长的25·71倍;小肠总长为1909.87cm,占肠道总长的70.50%;大肠总长为798.99cm,占肠道总长的29.50%。蒙原羚亚成体兼有精饲者和粗饲者的特征。     

成体和亚成体爪鲵端脑组织学初步研究

为了探讨爪鲵端脑的发育特点,充实比较神经生物学的研究资料,本文采用常规HE染色法,初步研究了成体和亚成体爪鲵端脑的组织学结构特征.结果 表明:爪鲵嗅球内细胞从外到内大致可分为6层结构,亚成体的细胞数量少于成体;成体爪鲵的侧脑室所占空间较大,脉络丛更为丰富,原始大脑皮层和原始海马都比亚成体发达,后者大脑内原始梨状区较为发达;隔区位于原始海马的下方,成体和亚成体都没有外侧隔核和内侧隔核之分,也没有外侧界沟作为原始梨状区和纹状体的分界,而在亚成体的侧脑室壁有内侧界沟区分原始海马和隔区,成体则没有;此外,爪鲵的纹状体属于古纹状体,杏仁核是位于第三脑室两侧的两个细胞团,端脑内细胞形态和大小分化较为单一.这些都表明亚成体爪鲵的端脑已大致具备了成体所具有的结构,并且也说明了爪鲵在两栖纲动物中属于较原始的种类,这在一定程度上填补了有关有尾两栖类神经系统资料以及神经发育资料的空白.     

甘肃盐池湾黑颈鹤亚成体夏季生境选择

开展对亚成体的研究,可以更加全面了解一个物种,进而更有效地开展保护工作。甘肃盐池湾国家级自然保护区是黑颈鹤（Grus nigricollis）成体的重要繁殖地和亚成体的重要栖息地之一。为研究甘肃盐池湾黑颈鹤亚成体生境选择,于2020年7月初至8月中旬在盐池湾党河湿地展开调查,并依据Johnson对生境选择空间尺度的划分,对亚成体活动区内各类型生境和觅食微生境的生境选择进行了研究。通过遥感影像解译和卫星跟踪分别获得各栖息地类型面积以及黑颈鹤的活动位点,利用核密度分析法估计活动区面积并利用Manly研究中的设计Ⅲ来研究活动区内各类型生境选择;通过选取利用样方和对照样方,使用χ2检验、独立样本t检验和Mann-Whitney U检验,对比检验样方数据,进行微生境选择的研究。结果表明,活动区内各类型生境中亚成体选择河流,拒绝戈壁和沼泽化草甸,对沼泽既不选择也不拒绝,而成体选择湖泊,没有利用河流,同时拒绝戈壁、山脉、沼泽化草甸和盐化草甸,对沼泽既不选择也不拒绝;觅食微生境选择中,亚成体选择平均植被盖度为57.07% ± 4.53%,基质类型为泥炭,基质硬度为中,主要植被黑褐苔草（Carex atrofusca）的微生境栖息,相比成体,亚成体选择的生境基质更硬,距道路距离更近,距房屋、河流、山脉和湖泊距离更远。亚成体的栖息地选择主要受到生境质量、生境资源有限性以及成体选择等因素的影响。在这些因素的影响下,亚成体与成体产生了生态位分离,并在栖息地选择上出现了分化。这种分化对亚成体的生存和成体的繁殖都有益,可以避免种内无效的冲突和竞争,有利于亚成体和成体的适合度增加。保护黑颈鹤的栖息环境需同时考虑到亚成体的选择和生存。     

亚成体中华蟾蜍端脑形态学与组织学的初步研究

为了探讨亚成体端脑的形态学和组织学特点,充实比较发育神经生物学的研究资料,本文采用脊椎动物神经标本制作技术和常规HE染色法,初步研究了亚成体中华蟾蜍端脑的形态学和组织学结构.结果表明:嗅球位于大脑半球的腹前外侧,细胞从外到内大致可分为7层结构;大脑半球内原始海马较原始梨状区发达;隔区位于原始海马的下方,有外侧隔核和内侧隔核之分;侧脑室的侧壁有内侧界沟区将始海马和隔区分开,也有外侧界沟作为原始梨状区和纹状体的分界;少量脉络丛伸入侧脑室;杏仁核是位于第三脑室两侧的两个细胞核团;纹状体是位于原始梨状区下方和侧脑室底部的细胞团,在两个侧脑室连通时较明显.此外,亚成体端脑内细胞形态和大小分化较为单一.本实验在一定程度上填补了有关无尾两柄类神经系统资料的空白.     

人羊膜来源成体干细胞的多向分化潜能

干细胞治疗被认为是一种非常有潜力的治疗手段,其中成体干细胞由于不存在伦理问题,更为广大学者所青睐。本研究成功从人羊膜间质细胞中分离纯化出具有自我更新能力和多向分化潜能的成体干细胞。首先从羊膜间质细胞中通过极限稀释法进一步分离得到羊膜来源成体干细胞(Amnion-derived stemcells,ADSC),分析其形态、生长方式及主要的免疫表型,并在体外分别将其向脂肪、成骨、内皮、肝细胞及神经细胞诱导分化。结果发现,ADSC在适宜条件下能够向3个胚层的细胞分化,经连续传代30次,其形态及表型稳定,并仍保持多向分化潜能。证实了ADSC的干细胞特性,可能为细胞治疗及干细胞工程提供种子细胞的新来源。     

A comparative study of the hyobranchial apparatus in Hynobiidae (Amphibia: Urodela)

The morphology of the adult hyobranchial apparatus has played an important role in understanding the systematics and evolution of urodeles, but the hyobranchial apparatus of hynobiid salamanders has received little attention so far. In this study, the hyobranchial apparatus of eight hynobiid salamanders (Hynobius leechii, Onychodactylus zhangyapingi, Ranodon sibiricus, Batrachuperus pinchonii, Salamandrella keyserlingii, Liua shihi, Pachyhynobius shangchengensis and Pseudohynobius flavomaculatus) is described and compared based on the clearing and double-staining method. The basic elements of the hyobranchial apparatus of the eight species are similar, including one basibranchial, cornua, one pair of radial loops, one pair of ceratohyals, one pair of hypobranchials II, one pair of ceratobranchials II, one urohyal (absent in O. zhangyapingi), one pair of the complex of hypobranchial I and ceratobranchial I (separated in certain species). Although the hyobranchial apparatus is similar among hynobiid salamanders and shows a unique morphological pattern, there are also certain species-specific distinctions that may be used for specific or generic diagnosis. The results of an ancestral state reconstruction of five traits showed that the ossified basibranchial, the presence of a separated hypobranchial I and ceratobranchial I, the absence of a urohyal, the ossified hypobranchial I and the partially ossified ceratohyal are derived traits. The state shown by the traits of each species is consistent with the phylogenetic position of each species. Compared with other Urodela, the hyobranchial apparatus of this group shows certain distinctive features that may represent the diagnostic characters of the family Hynobiidae. The partially ossified ceratohyal is correlated with the habitat and represents an ecological adaptation.     

Hyobranchial skeleton and hypobranchial muscles of rhipidistians

The hyobranchial skeleton of the porolepiform rhipidistian Laccognathus panderi Gross is described. The double composition of the ceratohyal in crossopterygians is proposed. The urohyal of porolepiforms, like that of Latimeria, consists of cartilaginous axial and membranous peripheral portions. The differences between porolepiforms and osteolepiforms in the structure of the hyobranchial skeleton, particularly, in the shape of the urohyal are attributable to different arrangements of the hypobranchial muscles. Porolepiforms and coelacanths have retained the coracomandibularis muscle inherited from early gnathostomes, whereas the same muscle of osteolepiforms was transformed into the geniohyoideus muscle. This transformation is accounted for by functional changes in the hyobranchial apparatus.     

Metamorphosis of cranial design in tiger salamanders (Ambystoma tigrinum): A morphometric analysis of ontogenetic change

While ontogenetic analyses of skull development have contributed to our understanding of phylogenetic patterns in vertebrates, there are few studies of taxa that undergo a relatively discrete and rapid change in morphology during development (metamorphosis). Morphological changes occurring in the head at metamorphosis in tiger salamanders (Ambystoma tigrinum) were quantified by a morphometric analysis of cranial osteology and myology to document patterns of change during metamorphosis. We employed a cross-sectional analysis using a sample of larvae just prior to metamorphosis and a sample of transformed individuals just after metamorphosis, as well as larvae undergoing metamorphosis. There were no differences in external size of the head among the larval and transformed samples. The hyobranchial apparatus showed many dramatic changes at metamorphosis, including shortening of ceratobranchial 1 and the basibranchial. The subarcualis rectus muscle increased greatly in length at metamorphosis, as did hypobranchial length and internasal distance. A truss analysis of dorsal skull shape showed that at metamorphosis the snout becomes wider, the maxillary and squamosal triangles rotate posteromedially, and the neurocranium shortens (while maintaining its width), resulting in an overall decrease in skull length at metamorphosis. These morphometric differences are interpreted in light of recent data on the functional morphology of feeding in salamanders. Morphological reorganization of the hyobranchial apparatus and shape changes in the skull are related to the acquisition of a novel terrestrial feeding mode (tongue projection) at metamorphosis. Metamorphic changes (both internal and external) that can be used to judge metamorphic condition are discussed.     

Osteologic development of the viscerocranial skeleton in sea bream: alternative ossification strategies in teleost fish

The ontogeny of the viscerocranial skeleton of sea bream Sparus aurata larvae was studied from 1 to 90 days post-hatching. In the smallest specimens analysed at 2·7 mm L _N no cephalic elements were present and at 3·1 mm L _N the following cartilaginous structures were visible: trabecula cranii, auditory capsule, Meckel's cartilage, quadrate, hyosymplectic cartilage, sclerotic, hypohyal, ceratohyal epihyal cartilage, interhyal, hypobranchial 1 and ceratobranchial 1. The only structure ossified at this size is the maxillary and the next ossified structures to appear are the preopercle and opercle at about 3·7 mm L _N. The last bones to appear are infraorbital 2 and 6 at 15·1 mm L _S. The first cartilaginous elements and structures to ossify in S. aurata appear to be related with functional requirements, so that structures involved directly in feeding and breathing generally appear and ossify before those that are not. The ontogeny of different regional structures revealed that generally the dermal bones ossify before the cartilage replacement bones. Comparison of S. aurata viscerocranial skeleton ontogeny with that of phylogenetically distant fish demonstrates that different ossification strategies exist in higher and lower teleost fish.     

The morphology and evolution of the ventral gill arch skeleton in batoid fishes (Chondrichthyes: Batoidea)

The ventral gill arch skeleton was examined in some representatives of batoid fishes. The homology of the components was elucidated by comparing similarities and differences among the components of the ventral gill arches in chondrichthyans, and attempts were made to justify the homology by giving causal mechanisms of chondrogenesis associated with the ventral gill arch skeleton. The ceratohyal is present in some batoid fishes, and its functional replacement, the pseudohyal, seems incomplete in most groups of batoid fishes, except in stingrays. The medial fusion of the pseudohyal with successive ceratobranchials occurs to varying degrees among stingray groups. The ankylosis between the last two ceratobranchials occurs uniquely in stingrays, and it serves as part of the insertion of the last pair of coracobranchialis muscles. The basihyal is possibly independently lost in electric rays, the stingray genus Urotrygon (except U. daviesi) and pelagic myiiobatoid stingrays. The first hypobranchial is oriented anteriorly or anteromedially, and it varies in shape and size among batoid fishes. It is represented by rami projecting posterolaterally from the basihyal in sawfishes, guitarfishes and skates. It consists of a small piece of cartilage which extends anteromedially from the medial end of the first ccratobranchial in electric rays. It is a large cartilaginous plate in most of stingrays. It is absent in pelagic myliobatoid stingrays. The remaining hypobranchial cartilages also vary in shape and size among batoid fishes. Torpedo and possibly the Jurassic Belemnobalis and Spathobatis possess the generalized or typical chondrichthyan ventral gill arch structure in which the hypobranchials form a Σ-shaped pattern. In the electric ray Hypnos and narkinidid and narcinidid electric rays, the hypobranchial components are oriented longitudinally along the mid-portion of the ventral gill arches. They form a single cartilaginous plate in the narkinidid electric rays, Narcine and Diplobatis. In guitarfishes and skates, the second hypobranchial is unspecialized, and in skates, it does not have a direct contact with the second ceratobranchial. In both groups, the third and fourth hypobranchials are composed of a small cartilage which forms a passage for the afferent branches of the ventral aorta and serve as part of the insertion of the coracobranchialis muscle. In sawfishes and stingrays, the hypobranchials appear to be included in the medial plate. In sawfishes, the second and third components separately chondrify in adults, but the fourth component appears to be fused with the middle medial plate. In stingrays, a large medial plate appears to include the second through to the last hypobranchial and most of the basibranchial copulae. The medial plate probably develops independently in sawfishes and stingrays. Because the last basibranchial copula appears to be a composite of one to two hypobranchials and at least two basibranchial copulae, the medial plate may be formed by several developmental processes of chondrogenesis. More detailed comparative anatomical and developmental studies are needed to unveil morphogenesis and patternings of the ventral gill arch skeleton in batoid fishes.     

Reconstruction of cranial and hyobranchial muscles in the triassic temnospondyl Gerrothorax provides evidence for akinetic suction feeding

The cranial and hyobranchial muscles of the Triassic temnospondyl Gerrothorax have been reconstructed based on direct evidence (spatial limitations, ossified muscle insertion sites on skull, mandible, and hyobranchium) and on phylogenetic reasoning (with extant basal actinopterygians and caudates as bracketing taxa). The skeletal and soft‐anatomical data allow the reconstruction of the feeding strike of this bottom‐dwelling, aquatic temnospondyl. The orientation of the muscle scars on the postglenoid area of the mandible indicates that the depressor mandibulae was indeed used for lowering the mandible and not to raise the skull as supposed previously and implies that the skull including the mandible must have been lifted off the ground during prey capture. It can thus be assumed that Gerrothorax raised the head toward the prey with the jaws still closed. Analogous to the bracketing taxa, subsequent mouth opening was caused by action of the strong epaxial muscles (further elevation of the head) and the depressor mandibulae and rectus cervicis (lowering of the mandible). During mouth opening, the action of the rectus cervicis muscle also rotated the hyobranchial apparatus ventrally and caudally, thus expanding the buccal cavity and causing the inflow of water with the prey through the mouth opening. The strongly developed depressor mandibulae and rectus cervicis, and the well ossified, large quadrate‐articular joint suggest that this action occurred rapidly and that powerful suction was generated. Also, the jaw adductors were well developed and enabled a rapid mouth closure. In contrast to extant caudate larvae and most extant actinopterygians (teleosts), no cranial kinesis was possible in the Gerrothorax skull, and therefore suction feeding was not as elaborate as in these extant forms. This reconstruction may guide future studies of feeding in extinct aquatic tetrapods with ossified hyobranchial apparatus. J. Morphol., 2013. © 2012 Wiley Periodicals, Inc.     

A complex hyobranchial apparatus in a Cretaceous dinosaur and the antiquity of avian paraglossalia

The highly specialized feeding apparatus of modern birds is characterized in part by paraglossalia, triangular bones or cartilages in the tongue that constitute part of the rarely fossilized hyobranchial apparatus. Here, we report on a new, juvenile specimen of the ankylosaurid dinosaur Pinacosaurus grangeri Gilmore, 1933 that provides the first evidence of paraglossalia outside of crown group Aves. The specimen is remarkable in preserving a well‐ossified hyobranchial apparatus, including paired paraglossalia, first and second ceratobranchials, epibranchials, and evidence of a median cartilaginous basihyal. Reassessment of Edmontonia, another ankylosaur, also reveals evidence of bony paraglossalia. Ankylosaur paraglossalia closely resemble those of birds, but are relatively larger and bear prominent muscle scars, supporting the hypothesis that ankylosaurs had fleshy, muscular tongues. The other hyobranchial elements, surprisingly, resemble those of terrestrially feeding salamanders. Ankylosaurs had reduced, slowly replacing teeth, as evidenced from dental histology, suggesting that they relied greatly on their tongues and hyobranchia for feeding. Some curved, rod‐like elements of other dinosaur hyobranchia are reinterpreted as second ceratobranchials, rather than first ceratobranchials as commonly construed. Ankylosaurs provide rare fossil evidence of deep homology in vertebrate branchial arches and expose severe biases against the preservation and collection of the hyobranchial apparatus. In light of these biases, we hypothesize that paraglossalia were present in the common ancestor of Dinosauria, indicating that some structures of the highly derived avian feeding apparatus were in place by the Triassic Period. © 2015 The Linnean Society of London     

Absence of Suction Feeding Ichthyosaurs and Its Implications for Triassic Mesopelagic Paleoecology

Mesozoic marine reptiles and modern marine mammals are often considered ecological analogs, but the extent of their similarity is largely unknown. Particularly important is the presence/absence of deep-diving suction feeders among Mesozoic marine reptiles because this would indicate the establishment of mesopelagic cephalopod and fish communities in the Mesozoic. A recent study suggested that diverse suction feeders, resembling the extant beaked whales, evolved among ichthyosaurs in the Triassic. However, this hypothesis has not been tested quantitatively. We examined four osteological features of jawed vertebrates that are closely linked to the mechanism of suction feeding, namely hyoid corpus ossification/calcification, hyobranchial apparatus robustness, mandibular bluntness, and mandibular pressure concentration index. Measurements were taken from 18 species of Triassic and Early Jurassic ichthyosaurs, including the presumed suction feeders. Statistical comparisons with extant sharks and marine mammals of known diets suggest that ichthyosaurian hyobranchial bones are significantly more slender than in suction-feeding sharks or cetaceans but similar to those of ram-feeding sharks. Most importantly, an ossified hyoid corpus to which hyoid retractor muscles attach is unknown in all but one ichthyosaur, whereas a strong integration of the ossified corpus and cornua of the hyobranchial apparatus has been identified in the literature as an important feature of suction feeders. Also, ichthyosaurian mandibles do not narrow rapidly to allow high suction pressure concentration within the oral cavity, unlike in beaked whales or sperm whales. In conclusion, it is most likely that Triassic and Early Jurassic ichthyosaurs were ‘ram-feeders’, without any beaked-whale-like suction feeder among them. When combined with the inferred inability for dim-light vision in relevant Triassic ichthyosaurs, the fossil record of ichthyosaurs does not suggest the establishment of modern-style mesopelagic animal communities in the Triassic. This new interpretation matches the fossil record of coleoids, which indicates the absence of soft-bodied deepwater species in the Triassic.