海洋爬行动物，即可以在海洋中生存的爬行动物，是群再次适应水生环境或半水生环境的爬行动物。在大陆架水域中最常见的两种海洋爬行动物是海龟和海蛇，它们都是冷血动物，因此这两种动物的种群数量都从热带向两极迅速递减。

Marine reptiles, or reptiles that can survive in the ocean, are groups of reptiles that are again adapted to aquatic or semi-aquatic environments. The two most common marine reptiles found in shelf waters are sea turtles and sea snakes, both of which are cold-blooded and therefore have rapidly declining populations from the tropics to the two poles.

现存海洋爬行动物包括海龟、海鳄和海蛇三类，已灭绝的包括鱼龙，蛇颈龙等。

The extant marine reptiles include sea turtles, sea crocodiles and sea snakes, while the extinct ones include ichthyosaurs and plesiosaurs.

简介

Introduction

海龟与海蛇类爬行动物现主要生产于暖水海洋中，位于北半球暖温带的青岛近海，只是偶然的机会，在夏、秋季海水温度升高的时候才能发现其行迹，而且数量较少。

Sea turtles and sea snakes are now mainly produced in warm oceans located in the offshore areas of Qingdao in the warm temperate zone of the northern hemisphere. They can only be found by chance in the summer and autumn when sea temperatures rise, and the number is quite small.

海龟是海洋中最为常见的而且是最为温驯的海洋爬行动物之一，其中有很多罕见的种类，比如鹰头龟，是在2005年时沿海渔民发现的，因为这种海龟原不是本海域种类，所以比较罕见，其性格比较凶猛，以小虾、小鱼为食，是海龟中比较少的纯食肉类海龟；我国青岛记录的海龟鳖目海龟科有海龟和蚋龟；棱皮龟科有棱皮龟，均以甲壳动物、软体动物和鱼类为饵，是国家保护动物。

Sea turtles are one of the most common and tame marine reptiles in the ocean, and there are many rare species, such as the hawk-headed turtle, which was found by fishermen in 2005 in coastal areas. Because this kind of turtle is not originally from the sea, it is relatively rare. It is fierce and feeds on small shrimps and fish, being one of the few sea turtles that are purely carnivorous. So far, the chelonia recorded in Qingdao include sea turtle and Rui turtle; the leatherback sea turtles belong to the family of leatherback turtles, all of which feed on crustaceans, mollusks and fish, and they are national protected animal.

海蛇以青灰海蛇、青环海蛇和淡灰海蛇三种较常见，一般栖息于近海无人居住的海岛附近。海蛇在我国青岛沿海也不多见。

Sea snakes are more commonly found near uninhabited offshore islands, including hydrophis caerulescens, chittue and hydrophis ornatus, and they are also rare along the coast of Qingdao in China.

特征

Characteristics

(1)皮肤干燥，缺乏腺体，表皮角质化程度高，外被角质鳞片或盾片或兼有来源于真皮的骨板。

(1) dry skin; lacking glands; the epidermis is highly keratinized and covered with keratinous scales or shields or with bony plates derived from the dermis.

(2)肺比两本类更为发达；呼吸系统已趋于完善；胸廓的出现，加强了呼吸机能。

(2) The lungs are more developed; the respiratory system has been perfected; the appearance of the thorax has strengthened the respiratory function.

(3)骨骼骨化程度高，结合牢固，转动较灵活，较好地适应陆地生活。适于陆地爬行。

(3) The skeleton is highly ossified, firmly combined and more flexible while rotation, which helps it to better adapt to the land crawling.

(4)心脏二心房一心室，但心室内有隔膜，已接近完全的双循环，循环机能和效率大为提高。

(4) It has two atria and one ventricle, but the ventricle has a septum, which is a system like that of a complete double circulation, greatly improving the circulatory function and efficiency.

(5)爬行类肾脏为进步性后肾，具有较高的排泄机能。

(5) The kidneys of reptiles are progressive posterior kidneys with a higher excretory function.

(6)神经系统和感觉器官发达，提高了对外界环境的适应能力。但爬行类仍为变温动物。

(6) The nerve system and sense organs are well developed, improving the ability to adapt to the external environment. However, reptiles are still metamorphic animals.

(7)体内受精提高了受精率。

(7) In vivo fertilization has improved the fertilization rate.

(8)爬行类产具有丰富卵黄和保护性卵壳的大型羊膜卵，获得了在陆上繁殖的能力。

(8) Reptiles produce large amniotic eggs with abundant yolk and protective shells and have acquired the ability to reproduce on land. 

身体构造

Body structure

生活在海洋环境里的爬行动物很少见。事实上，在已知的6000种爬行动物中，仅仅只有1%(约60种)住在海里。这些类群包括蜥蜴类、鳄鱼类、龟类和蛇类。每一类都和所有已知的爬行动物有着许多相同的解剖学结构：冷血、呼吸空气、有鳞片以及通过体内受精繁殖等。然而，为了能够在海水中生活，这些海洋爬行动物也进化出一些特殊的适应性，陆地爬行动物没有这些适应性。

Reptiles that live in marine environments are rare. In fact, of the 6,000-known species of reptiles, only 1% (about 60 species) live in the sea. These taxa include lizards, crocodilians, turtles and snakes. Each of these groups shares many of the same anatomy as all known reptiles: cold-blooded, air-breathing, scaly, and reproducing by internal fertilization. However, in order to be able to live in seawater, these marine reptiles have also evolved some special adaptations that terrestrial reptiles do not have.

绝大多数呼吸空气的脊椎动物不能直接饮用咸水。因为那样会造成脱水，还会对肾脏造成伤害。海水里含有的氯化钠和其他盐类的浓度，比血液和体液中的要高出3倍。许多海洋爬行动物能够饮用海水，那是因为它们的体内有种特殊的腺体(盐腺)可以排出过多的盐分。为了减少体液中的盐分，这些腺体可以排出比海水浓2倍的高盐溶液。盐腺的工作效率很高，它处理、排泄盐分的速率比肾脏快10倍。盐腺一般位于头部,，通常长在靠近眼睛的地方。

The vast majority of air-breathing vertebrates cannot drink salt water directly because that would cause dehydration and also cause damage to the kidneys. Seawater contains concentrations of sodium chloride and other salts that are three times higher than those in blood and body fluids. Many marine reptiles are able to drink seawater because they have a special gland (salt gland) in their bodies that can excrete excess salt. In order to reduce the salt in body fluids, these glands can excrete a high salt solution that is two times thicker than seawater. The salt glands work so efficiently that they can process and excrete salt 10 times faster than the kidneys. Salt glands are usually located in the head, which are near the eyes.

大约有50种海蛇栖息在海洋里。潜水时，海蛇可以通过关闭鼻膜和嘴巴周围的鳞片，将海水排斥在体外。它们平展的尾巴就像一把小船桨，轻松推动身体前进。海蛇的肺是一个拉长的强健的气囊，可以贮备氧气。此外，海蛇还可以通过皮肤摄入氧气。这些对海洋环境的适应性，使海蛇可在水下待上30分钟到2个小时。当然，这种本领也要付出相应的代价。由于海蛇通常需要游到水面上呼吸，所以它们要比陆地上生活的蛇类消耗更多的能量。

There are about 50 species of sea snakes that inhabit the ocean. When diving, sea snakes can repel seawater from their bodies by closing their nasal membranes and the scales around their mouths. Their spreading tails act like a small oar, easily propelling their bodies forward. A sea snake’s lung is like an elongated and robust air sac that store oxygen. In addition, sea snakes can take in oxygen through their skin. These adaptations to the marine environment allow sea snakes to stay underwater for 30 minutes to two hours. Of course, this ability comes at a price. Because sea snakes usually need to swim to the surface to breathe, they have to consume more energy than snakes living on land.