后毒牙类毒蛇

长期以来,人们仅把具有沟牙和管牙的蛇视为毒蛇,然而,近年来发现游蛇科中的虎斑颈槽蛇、红脖颈槽蛇、颈棱蛇、赤链蛇等既无管牙,也无沟牙,却频频发生这类蛇咬伤人后引起中毒的事例,甚至出现被咬伤致严重出血休克死亡的事件。经深入研究后发现,这些蛇虽没有沟牙和管牙,但却具有产生毒性分泌物的毒腺—杜氏腺(Duvernoy′s gland)及皮下腺,且不同的毒腺具有不同的毒性作用,可表现为出血不止、溶血、呼吸困难、肾损害等。这类蛇与毒腺的导管有联系的上颌牙明显粗大,上颌牙与上颌骨、横骨连接牢固,毒腺里的毒液可顺着粗大的上颌牙流入伤口,因此,应视为"后毒牙类毒蛇"。

The variety of poisonous snakes with venom duct fangs

In the past,people only regarded those which have solenoglyphic teeth and ditch teeth as poisonous snakes.Rhabdophis tigrinus,Rhabdophis subminiatus,Macropisthodon rudis,Dinodon rufozonatum.However,the people who had been bitten by some snakes were reported that they were seriously bleeding and even the hemorrhage shock.This kind of snakes belong to colubridae-the natrix tigrina lateralis,but have no solenoglyphi teeth or ditch teeth.With deeply research,we found that this kind of snakes which have Duvernoy's glands and hypodermal's glands instead of solenoglyphic teeth and ditch teeth can produce toxic secretion with venom glands.Besides,different venom gland has different toxicity such as continuously bleeding,hemolysis,hard-breathing,kidney damages and so on.Its upper teeth which link to the duct of venom gland are obviously big and line the maxillary bone and transversum firmly,then its toxic liquid in the venom gland can flow through the upper teeth into the wound.Therefore,it should be regarded as the "varieties of vipers with venom duct fangs".