Relationship Between Breeding Systems and Resistance to Mercury In Euplotes crassus (Ciliophora Hypotrichida)

Abstract

A toxicity bioassay was used to measure the median tolerance limit to Hg2+ of different stocks of the marine hypotrichous ciliate E. crassus. The stocks were representatives of local populations diversified in their breeding systems (inbreeding or outbreeding). Results showed a greater tolerance to Hg in outbreeders. Genetic analysis of interstock tolerance-differences indicated no simple genetic basis. Different degrees of Hg tolerance revealed by the representatives of inbreeding and outbreeding populations could depend on their peculiar genetic organizations. Such peculiar genetic organizations might be the product of the distinct ecogenetic strategies followed by the populations to which the stocks belonged.