Imposex has also been reported to occur in Nassarius reticulans and 

 Ocenebra erinacea and has been found to occur in the U.S. and in Europe 

 (Smith, 1980, 1981; Bryan et al., 1987; Gibbs et al., 1987). 



4.3.5 Fish 



The most sensitive of the adult fish tested is the Chinook salmon 

 Oncorhynchus tshawytscha . Table 4.13 summarizes the acute toxicity values 

 of tributyltin reported in the literature for fish by species. The least 

 sensitive fish of those tested for acute effects is the muramichog Fundulus 

 heteroclitus . Table 4.14 summarizes the sublethal effects of exposure of 

 fish to low levels of tributyltin. Most of the effects studied have been 

 histological or behavioral. The ability of fish to detect the presence of 

 TBT has been suggested to be at or below the level at which the fish 

 exhibits active avoidance behavior. Although the mummichog is relatively 

 tolerant of TBT in terms of acute toxicity, the fish exhibited avoidance 

 behavior at 1.0 ppb. 



IV- 28 



