Origin and Evolution of some Biological Characters of Anabarilius grahami As Referred To Geological Development of Fuxian Lake

摘要: Based on data collected in Fuxian Lake from November,1988 to March,1991,the habits living spaces,feeding and breeding of Anabarilius grahami (Regan) have been described.From the view organic evolution geological development lake,the origin these biological characters further discussed.The A.grahami are closely correlated its origination.It shares a most recent common ancestor with A.andersoni A.qiluensis (Yang et al.,1987).Their would be streamlived omnivorous fish because primitive extant species all stream-dwellers.A.grahami is endemic Lake.Some also lake.Fuxian was formed late Pliocene as result Fault depressions (Nanjing Institute Geography Limnology al.,1989;Yang,1984).Since formation,the lake has generally followed deepening oligotrophic development.It unique origination deepening,oligotrophic that produced profound eftects A.grahami.1.A.grahami prefers breed at outlets cave springs or hill substrate water current sites similar streams.This habit supposed descended therefore should character.2.The larvas adults occupy different spaces.The smaller than 30 mm SL occur shallow coastal region middle upper layers open water.Similar possessed by Barbodes fuxianensis,B.chonglingchungi percocypris pingi regani which live same lake.According recapitulation rule,the character.3.A.grahami close phylogenetic relationship al.,1987).All them feed mainly planktons.They undergone differentiations gill rakers.A.grahami 31-39 rakers,length rakers 46.7%-55.6% filaments having numerous secondary rakers.By contrast,A.andersoni 21-25 22-25 30.0%-54.0% 35.4%-45.1% filaments,having less rakers.Comparison indicates evolved developed filtering organ corresponding environment.4.A.grahami long annual season temporally regular interval between two sequent spawning populations.These had ensure enough food for full use limited adaptations lake.5.A.grahami lower absolute relative fecundities Xingyun Lake.Interspecific were resulted developments Lakes.Xingyun shallowing eutrophic A.ander soni higher fecundities.Howerver shortage led lowering fecondities A.grahami.6.Population many more females males,females being 4.1 times males.Dominant can potentially high fecundity population.