头足类角质颚研究进展Ⅱ——运动、分类与生态

Progress of beak in cephalopod Ⅱ——movement,taxonomy and ecology

头足类的资源开发和利用已经得到各国的普遍重视,对其基础生物学等方面的研究得到不断的发展。作为头足类的主要捕食器官之一,角质颚这种不靠关节、仅靠肌肉收缩来运动的方式引起了学者们极大的兴趣,同时其固有的形态特点是分类学的良好性状,所包含的大量信息也可以用于生态学方面的研究。本文根据国内外学者对其运动模式的解释,阐述了相关结构的特点,同时对角质颚在头足类分类和生态学等方面的应用研究做了综述。回顾前人的研究发现,对角质颚的功能性研究已有一定的成果,今后的研究应该更加关注对角质颚特征定量整理,并编制检索表,同时根据该结构中的信息,分析头足类在生态系统中的准确定位和相关的环境关系。

The exploitation and utilization of cephalopod resource have been recognized gradually in the world and studies on its basic biology have made much progress.As one of the hard structures of main predation organs,beak attracted many experts for its muscle contraction without any joint.The movement pattern has its own system,three muscle parts,superior mandibular muscle,lateral muscle and inferior mandibular muscle take their responsibibities for opening and closing,completing the grind and chewing.The whole movement was guided by the nerve stimulation and electromyography explained the principle of muscle motion.Meanwhile,the inherent morphology was a good material for taxonomy,and the storage of information was also useful for ecological study.From the unique character of the rostrum,wing and lateral wall,length,radian and fold are important features in classification.With the anticorrosion character,beak will be easily found in the stomach of many marine mammals.Thus,we could know the dominant species of cephalopod in this area and also individual size could be speculated by the beak and mantle length relation.Diet preference of these mammals will be reflected from the residual beaks.The relationship between invertebrate and vertebrate can also be detected.For the completed structure,beak contains many trace elements,and stable isotopes analysis is also a new method for study of marine food web.Researchers come up with the new method for long term diet analysis through stable isotopes from continuous sampling by hard structures.The carbon stable isotope 13C could retrospect the habitat and migration pattern,and nitrogen stable isotope 15N can always be enriched through food chain,so the trophic level could be deduced.Based on the studies conducted by some researchers at home and abroad,we described the movement pattern of beak and its structure characters,reviewd the studies of beaks applied in cephalopod taxonomy and ecology.In conclusion,the special movement pattern will inspire us to mimic the similar device which can be utilized in machine area,this is a progress in bionics.In view of the shortage of deep sea cephalopods,we should collect more quantitate characters to compile identification key,distinguish different features of species,and know more about the mysterious marine organism.Using stable isotopes,we could analyze the relationship between ecosystem position and related environment variation,and it is also a more credible way to explore the migration trajectory of cephalopod,which is hard to determine the correctness for lack of the exact evidence by other traditional methods.Beak is a practical material for the future application research,we should pay more attention to the hard structure.