Abstract
Successful induction of two kinds of triploid abalone animals (abbreviated as 3n.1pb and 3n.2pb respectively), by inhibiting release of first or second polar body, was reported recently.
The present work examines associations between thermostability variations of enzymes at multiple loci and temperature tolerance in terms of survival of animals against high and/or low temperature stresses within each group of diploid and triploid animals, induced artificially, and compared such temperature tolerances between normal diploid (2n) and two kinds of triploid sib animals of the Pacific abalone Haliotis discus hannai. Significantly higher survivals of animals homozygous of thermo-resistant allele at phosphoglucomutase and malate dehydrogenase thermo-stability loci against high water temperature stress as well as of those homozygous of thermo-sensitive allele at malate dehydrogenase thermostability locus against low water temperature stress were observed. Comparison of high temperature tolerances between different ploidy sib animals indicated the greatest survival in the animals of 3n.1pb group, followed by 2n and the least survival in 3n.2pb group. In addition, a combined effect of chromosome-set manipulation and selected genotype of thermostability variations was seen, suggesting a possible immediate application of the results of such observations towards greater productivity in abalone aquaculture through an appropriate selective breeding programme.
