摘要

Discriminating the male influence on egg fertilization in Penaeus monodon is needed so that accurate measures of male fertility can be developed and subsequently used to evaluate methods aimed at improving fertility. In this study, we employed a novel, pairwise comparison approach to discriminating the fertilization influence of males: female broodstock were artificially inseminated with one spermatophore each from a pair of males. We achieved 22 successful 'spawnings' involving selected pairs from 33 males, and estimated the proportion of embryos fertilized by each paired male by individual genotyping of embryos. The non-inseminated, 'twin' spermatophore was used to estimate measures of male fertility; sperm number and the number of normal sperm of each inseminated spermatophore. Relationships between measures of male fertility and egg fertilization were then evaluated. Using this approach we were able to show that the egg fertilization potential of males could not be determined simply by total sperm number or the number of normal sperm (as determined by gross morphology under light microscopy). We also found extremely high variability in fertilization between paired males. The results highlighted male infertility issues (e.g. sperm viability) that are not simply overcome by greater sperm numbers. Our novel approach provides a method that can be used to determine whether more complex measures of male fertility can reliably predict egg fertilization potential.

  • 单位
    CSIRO