CAJ | 학술논문

长江中下游流域是我国淡水贝类多样性最为集中的地区,然而由于人类活动的影响,淡水贝类已成为高度濒危的类群.为有效保护淡水贝类的多样性,我们于2003年6月.2005年5月对长江中下游流域13个水体软体动物的多样性及分布进行了调查.共采集到软体动物69种(中国特有种42种),隶属于腹足类9科14属29种和瓣鳃类5科17属40种.其中,蚌科和田螺科是种类数最多的两个科,分别占总种类数的50.7%和14.5%.不同类型湖泊软体动物种类数的差别较大.通江湖泊所占种类数相对丰富,尤其是适应流水的种类,如河螺属、短沟蜷属及蚌科的种类.大型通江湖泊鄱阳湖和洞庭湖软体动物的种类数和特有种数分别66种和40种,分别占总种类数和总特有种数的95.7%和95.2%.阻隔水体所占种类数相对较少,种类数为4-19种.与历史资料相比,长江中下游湖泊软体动物的种类数和特有种数均减少50%左右,且多数种类的分布范围也明显缩小.造成贝类资源衰退的可能原因主要是江湖阻隔所引起的整个江湖复合系统栖息地和水文情势的改变,其他的人为活动如过度捕捞、围垦及废污水的过度排放等也可能是其中的重要原因.
장강중하유류역시아국담수패류다양성최위집중적지구,연이유우인류활동적영향,담수패류이성위고도빈위적류군.위유효보호담수패류적다양성,아문우2003년6월.2005년5월대장강중하유류역13개수체연체동물적다양성급분포진행료조사.공채집도연체동물69충(중국특유충42충),대속우복족류9과14속29충화판새류5과17속40충.기중,방과화전라과시충류수최다적량개과,분별점총충류수적50.7%화14.5%.불동류형호박연체동물충류수적차별교대.통강호박소점충류수상대봉부,우기시괄응류수적충류,여하라속、단구권속급방과적충류.대형통강호박파양호화동정호연체동물적충류수화특유충수분별66충화40충,분별점총충류수화총특유충수적95.7%화95.2%.조격수체소점충류수상대교소,충류수위4-19충.여역사자료상비,장강중하유호박연체동물적충류수화특유충수균감소50%좌우,차다수충류적분포범위야명현축소.조성패류자원쇠퇴적가능원인주요시강호조격소인기적정개강호복합계통서식지화수문정세적개변,기타적인위활동여과도포로、위은급폐오수적과도배방등야가능시기중적중요원인.
In China,the most diverse molluscan fauna occurs in the Yangtze basin.The molluscan fauna in this region are highly imperiled due to increasing human activities.Aiming at effective conservation of the deteriorating molluscan fauna, intensive field investigations of freshwater molluscs on the mid-lower Yangtze Lakes were conducted between June,2003 and May,2005.Altogether 69 species were identified during the collection,including 29 gastropod species belonging to 9 families,40 bivalve species belonging to 5 families,and 42 endemic species.Among them,Unionidae and Viviparidae are the two families with the highest species numbers.accounting for 50.7%and 14.5%ofthe total,respectively.The diversity varies greatly from take to lake.River-connected lakes contain the most diverse fauna,especially those adapted to lotic habitat,su as Rivularia spp,Semisulcospira spp and some cies of Unionidae.In the two large river-connected lakes,Poyang Lake and Dongting Lake,there are 66 species and 40 endemic species,accounting for 95.7% of the total species number and 95.2% of the total endemic species number, respectively.In contrast,the historical records,it is found that total species number and endemic species number decreased greatly,with a loss of about 50% of the historical records.Meanwhile,the distribution ranges of most taxa were also shrunk.Habitat loss and hydrological alteration in the Yangtze Potamo-lacustrine Complex Ecosystem caused by river-lake isolation should be the primary factor causing the decline of molluscan fauna.Other human activities, such as overharvesting,reclamation and pollution,may be also the important factors.