鼋骨骼系统及与中华鳖比较

SKELETAL SYSTEM ANALYSIS OF ASIAN GIANT SOFT-SHELLED TURTLES AND COMPARISON WITH CHINESE SOFT-SHELL TURTLE

  • 摘要: 采用虫蚀法制备了鼋Pelochelys cantorii和中华鳖Pelodiscus sinensis的骨骼标本, 对骨骼系统进行了观察、描述、绘图及比较分析。结果显示, 鼋的骨骼共169枚, 由背甲和腹甲组成的外骨骼、中轴骨和附肢骨组成的内骨骼组成。通过比较鼋和中华鳖的骨骼结构, 发现二者在头骨的吻突长度及第三颈椎结构方面有较大差别。鼋眼眶前部至吻突最前端的长度与头骨总长度比为0.082, 而中华鳖为0.570, 显示中华鳖吻突显著长于鼋。鼋与中华鳖的颈椎骨数目均为9枚, 但中华鳖的第三至第九颈椎的横突要更明显, 第七颈椎的椎体向上显著翘起, 且第九颈椎腹面椎体前端为尖状。从整条颈椎上看, 鼋脊椎长度与其背甲长度之比为0.66, 中华鳖为1.07, 表明中华鳖的颈椎更长; 研究结果丰富了鳖科动物的骨骼学基础数据, 也为鼋物种鉴定、龟鳖动物系统演化及生态适应性提供骨骼学理论依据。

     

    Abstract: Asian giant soft-shelled turtle is one of the first class protected animals in China, and is an extremely endangered species. Now, there are only 13 sexually mature Asian giant soft-shelled turtles in captivity in China. Due to fill the blank in the study of Asian giant soft-shelled turtle skeleton system, this study described the morphological characteristics of the complete skeletal system of Asian giant soft-shelled turtles and Chinese soft-shell turtles, and draws a diagram. The frozen samples of two Asian giant soft-shelled turtles and one Chinese soft-shell turtle were studied in this study. After the processes such asdefrosting and dissection, we used larva of Tenebrio molitor to manufactured skull specimen of the turtles. Removed the bones and rinsed with water to dry them. Then the vernier calipers were used to measured each bone structure and take photos, and the shapes were hand-drawn with reference to the bone entities and photos. A total of 169 bone fragments were found, consisting of exoskeleton of dorsal and ventral armor, endoskeleton of midshaft bone and appendage bone. Meanwhile, the skeletal structure of Asian giant soft-shelled turtle and Chinese soft-shell turtle had significant differences in snout length and the third cervical spine structure. The ratio of the length from the anterior orbit of soft-sheller to the most tip of the muzzle to the total length of skull was 0.082 for Asian giant soft-shelled turtle and 0.570 for the Chinese soft-shell turtle. Although the number of cervical vertebrae bones of Asian giant soft-shelled turtle and Chinese soft-shell turtle was 9, the transverse process of the third to ninth cervical vertebrae of Chinese soft-shell turtle was more obvious, the cone of the seventh cervical vertebrae was obviously warped upward, and the front end of the abdominal cone of the ninth cervical vertebrae was pointed. From the whole cervical spine, the ratio of the length of the spine of to the length of its back armor is 0.66 for the Asian giant soft-shelled turtle and 1.07 for the Chinese soft-shell turtle. These results provide the basis for the identification of Asian giant soft-shelled turtles, the phylogenetic evolution and ecological adaptability of turtles, indicating that Asian giant soft-shelled turtles are primitive reptiles with an important role in animal evolution.

     

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