中文摘要：

捕获黄河上游玛曲段极边扁咽齿鱼,在甘肃省临夏国家级鲑鳟鱼良种场驯养后,进行人工繁殖研究。结果发现,极边扁咽齿鱼繁殖期为5-6月,雌鱼和雄鱼都在6龄达到性成熟,雌鱼成熟系数为18.19%～23.02%,雄鱼成熟系数为7.13%～8.34%。成熟卵径为（2.1±0.1）mm,每克卵子数为134.9粒,绝对繁殖力为12630～40470粒,相对繁殖力为每克体重12.6～28.78粒。通过干法授精,两年累计孵化极边扁咽齿鱼受精卵14万粒,平均受精率87.5%,平均发眼率77.5%,平均上浮率72%,发育平均积温为6321.5℃·h。

英文摘要：

Platypharodon extremus,an endemic fish belongs to Platypharodon of Schizothoracinae,Cyprinidae,and lives only in the upstream area of the Yellow River,the hinterland of the Qinghai-Tibet Plateau,which was a small population size,narrow distribution,threatened species in China.It was included in the ＂China’s Red Book of Endangered Species of Animals-Fish＂,Vulnerable （V） .As the Qinghai-Tibet Plateau’s unique geographical location,P.extremus has adapted in the long-term evolution of the high altitude,strong radiation,low water temperature and other special environments,which also show the remarkably adaptable characteristics.With the intensification of human activities in recent years,the habitat changes and fragmentation,habitat barriers,water pollution,overfishing,the short growing seasons,slow growth rate,late age of sexual maturity and other factors,the populations of the species development were greatly limited.At present,the main distribution area has been gradually reduced to the upstream area of the Yellow River.At present,the population structure changed,the resource declined,the age structure turns into an extent status,the population of three investigation points where aboundance in the last time had disappeared today.However,the artificial propagation of this fish did not succeed.To explore the complete artificial propagation and in order to lay the groundwork for its resources enhancement.In this paper,P.extremus were captured from the Maqu at upper reaches of Yellow River and studies on techniques of artificial propagation and breeding were carried out in Linxia National Salmons Fishery Farm in Gansu province from 2007 to 2009.When reared for one year in pond in Linxia,some of the fish become mature.And,behaviours of propagation of the fish in nature could be controlled by adjusting the ecologic condition of environment they lived in.With the experimentation of artificial propagation for several years,some data of propagation and characteristics of P.extremus have been obtained.Under the a