Resource Status And Reproductive Traits Of Freshwater Bivalves In The Poyang Lake

Bivalves are one of most important part of freshwater biodiversity and they are of crucial roles in freshwater ecology,and very useful as indicators of watershed health and recorders of watershed changes.In 2007,resource status of Poyangy Lake were surveyed,and reproduction trait of dominants were investigate.The result were summarized as follows:1.A total of 50 species and subsepcies were found,of which 47 species and subsepcies belong to family Unionidae,2 species belong to family Corbiculidae and last 1 special belong to family Mytilidae.The main part of bivalve fauna in Poyang lake were Unionids.Unio douglasiae,Lamprotula caveata,Lamprotula leai, Lamprotula rochechouarti,Cuneopsis pisciculus,Anodota woodiana,Corbicula fluminea were dominants.Lepidodesma languilati,Solenaia oleivora,Solenaia carinatus,Lamprotula polysticta etc.al with low appearance frequency were rarity species in this area.2.The maximum relative abundance sepcie in Poyang Lake and nearby rivers was Corbicula fluminea,and mean dinsity was 7.823 ind./m~2.The Unionids dinsity was significantly smaller then former.The maximum relatively abundance unionids were Unio douglasiae 0.4411ind./m~2.The biomass showed the same signs.3.Analyse indicated that the relative abundance of bivalves in the shallow water was higher than in deep water.But,there were no significant differences between the species richness and water depth in Poyang Lake.Mostly,bivalves prefered fine substrate composed with silt and sand.4.Length of all the specimen were measured and population structure description was given,Most of species were in declining status,comparing with historical date,many species were endangered which were awfully hard to find live specimens for instance Solenaia oleivora and Solenaia carinatus. 5.Fecundity of 10 mussel were calculated,relationship between fecundity and shell length were analysed.The result indicate that fecundity of 10 mussel ranged from 7800 to 610000,mean shell length of Anodota woodiana were 12.70cm,and fecundity were 610000.