Patterns of emergence and survival of Conchophthirus acuminatus (Ciliophora : Conchophthiridae) from Dreissena polymorpha (Bivalvia : Dreissenidae)

摘要

This is the first study to quantify the periodic emergence of a Conchophthirus sp. from its bivalve host. Emergence rates of C. acuminatus from Dreissena polymorpha over the entire 24-day experiment appeared to be directly correlated with infection intensity. The rate of ciliate emergence from individual mussels varied considerably throughout the experiment at both 14degreesC and 21degreesC. It was not uncommon to have a sampling period in which no emergence was observed immediately followed by a period of high emergence, e.g., at 14degreesC from 0 to 25 ciliates and at 21degreesC from 0 to 720 ciliates. The total mean number of ciliates that were observed to have emerged from each mussel during the 24-day experiment was significantly higher at 21degreesC (207 ciliates/mussel) than at 14degreesC (29 ciliates/mussel). Our experiments suggested that C. acuminatus have a short survival period outside their host. Although we observed a maximum survival period of 144 hr (6 days), most ciliates died within 48 h.