Consideration of Reproductive Traits of Unionid mussels by Drift distance and Transport distance

Abstract

Many kinds of unionid mussels inhabit the H?dashi canal. 1) The reproductive period of unionids in the irrigation canal was approximately three years; 2) Young specimens had been transported 120 m downstream by the time they reached sexual maturity; 3) They required 10 seconds or more to parasitize their host, the pond loach, which in terms of current works out to a flow rate of 0.012 m/s or less; 4) For parasitization to take place, over 10,000 glochidia needed to be released per day over a period of 15 days; and 5) It was calculated that the host fish had transported the glochidia for 275 m or more.