地龟消化系统形态学及食性研究

发布时间：2018-11-09 15:11

【摘要】：地龟属于地龟科(Geoemydidae),地龟属(Geoemyda),共有两种,地龟(G.spengleri)和日本地龟(G.japoica)。地龟在我国主要分布于海南、广东、广西等地区。近年来野外捕捉频繁,野外地龟种群遭到了严重破坏,且人工饲养条件下成活率极低。为了整体了解地龟的外部形态学概况,探究地龟消化系统的结构组成和相关参数,本文通过形态学方法详细对地龟的背甲、腹甲的盾片和骨板进行绘图和描述,并且通过大体解剖和活龟饲养的方法研究了地龟的消化道结构组成和食性。后期走访了地龟海南原产地的个别养殖户,获得了部分食性信息。从形态学方面看,地龟没有腋盾和胯盾,背甲和腹甲均由盾片和骨板构成。背甲盾片由颈盾(1枚)、椎盾(5枚)、臀盾(2枚)、缘盾(22枚)、肋盾(8枚)组成。背甲骨板由颈板(1枚)、椎板(7枚)、上臀板(2枚)、臀板(1枚)、缘板(22枚)组成。腹甲盾片由喉盾(2枚)、肱盾(2枚)、胸盾(2枚)、腹盾(2枚)、股盾(2枚)、肛盾(2枚)组成。腹甲骨板由上板(2枚)、内板(1枚)、舌板(2枚)、下板(2枚)、剑板(2枚)组成。地龟头部颈侧有鲜艳条纹,眼大。头顶部体色较深,头部的腹侧、喉部体色浅,有的个体呈淡黄色。上下喙略钩曲,外覆有齿龈,地龟的喙型和结构与其功能相适应。地龟的消化系统由消化道和消化腺两部分组成。消化道在形态学上主要分为口咽腔、食道、胃、小肠、大肠五部分。消化道全长为背甲最大直线长的3.70倍。小肠是地龟消化吸收的主要场所,占消化道全长的比例最大,为52.7%。消化腺主要有肝脏和胰腺,肝脏褐色,分为左右两肝叶,覆压包绕胃和肠。地龟平均肝重3.53g,肝体比为2.8%。胆囊在右肝叶内侧,同十二指肠部分接触。胰腺通过系膜伴随十二指肠,有复杂的管路通向肠道。解剖消化道后可以确定野生地龟的动物性食物主要是一些昆虫及其幼虫、马陆等。如双距螯蜂、条马陆等。人工饲养条件下,地龟可捕食昆虫纲、多足纲、寡毛纲、甲壳纲、蛛形纲等小型生物。通过野外调查走访养殖户可知地龟嗜食火龙果、环毛蚓、黄粉虫等。本文将人工投喂时地龟的捕食行为粗略分为观望、单眼凝视、靠近猎物、摄取猎物四个阶段。地龟消化系统形态学的研究为地龟保育救护提供了第一手的资料,有助于确定本种龟灌胃的进针深度,获得消化道的走向特征,填补了该种龟在相关领域的研究空白。对地龟消化道大体解剖后初步探明了其动物性食性的大致组成,丰富和补充了前人对地龟食性的研究结果。食性的相关研究结果有助于了解地龟的野外生境,为野生地龟保育时的食谱提供参考。
[Abstract]:There are two species of ground tortoise (G.spengleri) and Japanese ground tortoise (G.japoica) belonging to (Geoemyda), of (Geoemydidae), family. Land tortoise is mainly distributed in Hainan, Guangdong, Guangxi and other areas in China. In recent years, the wild tortoise population has been seriously damaged, and the survival rate is very low under the condition of artificial breeding. In order to understand the general situation of the external morphology of the ground tortoise and to explore the structure composition and related parameters of the digestive system of the ground turtle, this paper makes a detailed drawing and description of the back armour of the ground turtle, the shield and the bone plate of the abdominal armour by the morphological method. The composition of digestive tract and feeding habits of ground tortoise were studied by gross anatomy and live tortoise feeding. In the later period, I visited some farmers in Hainan origin and got some information about food consumption. Morphologically, the ground tortoise has no axillary shield and hip shield. The shield consists of cervical shield (1), vertebrae shield (5), gluteal shield (2), edge shield (22) and rib shield (8). The plate consists of cervical plate (1), lamina (7), superior gluteal plate (2), gluteal plate (1) and marginal plate (22). The shield consists of laryngeal shield (2), brachial shield (2), thoracic shield (2), abdominal shield (2), femoral shield (2), anal shield (2). The abdominal plate consists of upper plate (2 plates), inner plate (1 plate), tongue plate (2 plates), inferior plate (2 plates) and sword plate (2 plates). The neck of the tortoise has bright stripes and big eyes. The top of the head is darker, the ventral side of the head, the larynx pale, and some individuals pale yellow. The upper and lower beaks are slightly crooked and covered with gums. The beak and structure of the tortoise are suitable for its function. The digestive system of ground turtle consists of digestive tract and digestive gland. The digestive tract is mainly divided into oropharyngeal cavity, esophagus, stomach, small intestine and large intestine. The total length of digestive tract was 3.70 times as long as the maximum straight line length of dorsal armour. The small intestine is the main place for the digestion and absorption of the ground tortoise, accounting for the largest proportion of the total digestive tract, 52.7%. Digestive gland mainly has liver and pancreas, liver brown, divided into left and right liver lobes, wrapped around the stomach and intestine. The average liver weight was 3.53 g and the ratio of liver to body was 2.8 g. The gallbladder is on the medial side of the right lobe, in contact with the duodenum. The pancreas passes through the Mesangium with the duodenum and has a complex pipeline leading to the intestine. After dissecting the digestive tract, it can be determined that the animal food of wild ground turtle is mainly insects and their larvae. Such as double talus chelating bee, striped horse land, etc. Under the condition of artificial breeding, the ground tortoise can prey on insects, polypods, Oligochaetes, crustaceans, arachnids and other small organisms. Through field investigation, it is known that the tortoise is fond of eating dragon fruit, wormworm, powdery mildew and so on. In this paper, the predation behavior of ground tortoise during artificial feeding is roughly divided into four stages: watching, gazing with one eye, approaching prey and ingesting prey. The study of the morphology of the digestive system of the ground tortoise provides first-hand information for the conservation and rescue of the ground turtle, helps to determine the depth of the feeding needle, obtains the characteristics of the digestive tract, and fills up the blank in the research of the species in the related field. After the gross anatomy of the digestive tract of the ground turtle, the composition of its animal diet was preliminarily discovered, which enriched and supplemented the results of previous studies on the eating character of the ground turtle. The results of this study are helpful to understand the wild habitat of the tortoise and provide reference for the conservation diet of the wild tortoise.
【学位授予单位】：南京大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：S917.4

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