Study On The Reproductive Biology And Artificial Propagation Of Triplophysa Orientails (Herzenstein)

Triplophysa orientails(Herzenstein)as the premium ornament species of the Yarlung Tsangpo river is decorated with pattern outer covering.Triplophysa,including Triplophysa orientails,is one of the most important native fish in Tibet,which plays an important role in the high attitude and cold ecosystem of Tibet.However,only few reports are on fishery resources and taxonomy about Triplophysa in Tibet.In this paper,we studied the reproductive biology and artificial propagation of Triplophysa orientails in order to provide a basic reference for further understanding of the early life history and the related work on the protection of the fish proliferation in Tibet.Our main results are as follows:The male secondary sexual characteristic was very obvious in the breeding season,which can be used as the main method for identifying the male and female.As was shown,the sex ration was close to 1:1.Absolute fecundity(F)and relative fecundity of body length(FL)and relative fecundity of body weight(FW)were 714 ~ 32320(4483 + 5663)eggs,6 ~ 229(41 + 42)eggs/mm,95 ~ 903(302 + 221)eggs /g respectively.Absolute fecundity(F)showed significant correlation with body weight(W),gonad weight(WG),net weight(WN)and GSI,while relative fecundity of body length(FL)was significantly related with body weight(W),gonad weight(WG)and GSI,meanwhile relative fecundity of body weight(FW)showed significant correlation with body weight(W)and gonad weight(WG),as the analysis model described,F = 5016.444-1625.19 W + 10464.902 WG + 1343.718 WN-487.018 GSI(r = 0.968,P < 0.01),FL = 47.215-4.487 W + 70.928 WG-3.259 GSI(r = 0.928,P < 0.01),FW = 278.394 – 23.673 W + 255.236 WG(r = 0.731,P < 0.01).Egg diameter distribution frequency was inferred that the spawning type of Triplophysa orientalis(Herzenstein)was batch spawning.The mature unfertilized eggs of Triplophysa orientalis(Herzenstein)were viscous,ovoid,with a diameter of 0.97~1.11 mm and characterized with tiny adhesive encountering water.At a water temperature of(16±0.5)?,the embryonic development lasted 132 h and 9 min,with the cumulative temperature of 2113.6 ?·h.Additionally,the embryonic development can be divided into seven physiological periods: blastoderm formation stage,cleavage stage,blastula stage,gastrula stage,neural stage and organ formation stage.The newly hatched larvae was(4.86±0.09)mm.Furthermore,the post-embryonic development lasted 34 days at a water temperature of(16±0.5)?,which can be divided into the yolk sac and post larvae stage.The yolk sac lasted 9 days,and the post larvae stage lasted 25 days.