The effects of mercuric chloride and methylmercuric chloride on the developmental biology of the estuarine teleost Fundulus heteroclitus (Walbaum).

Embryos of the estuarine teleost, Fundulus heteroclitus, were exposed to Hg++ as mercuric chloride (MC) and methylmercuric chloride (MMC) under seven different exposure conditions. Four- to-eight cell stage embryos (0-day old) were exposed to four distinct treatment regimes (continuous, 5, 2 and 1 day of exposure) while mid-blastula (1-day old), mid-neurula (2-day old) and well-pigmented, beating heart (5-day old) stage embryos were exposed continuously to Hg++ concentrations derived from two test compounds.