Variation in acid tolerance of Connecticut wood frogs: genetic and maternal effects

Abstract

Acid tolerance in wood frog (Rana sylvatica) embryos and larvae was examined in full- and half-sib families. Among the embryos, no significant difference in acid tolerance at pH 3.75 was observed among the progeny of males. At pH 4 only slight differences in embryo acid tolerance existed among the progeny of males mated to the same female. Thus, there is relatively little direct genetic variation in embryo acid tolerance. However, progeny from different females differed significantly in their acid tolerance at both pH 4 and pH 3.75, indicating that maternal factors are important in embryo acid tolerance. Whether these maternal factors are genetic is not known. Among larvae, maternal factors did not appear to influence acid tolerance, but significant genetic variation was present. Larval survival in an acidic solution was not correlated with embryo acid tolerance.