Figure 1. Reaction norms showing the different responses of eight male genotypes to temperature and pH.

The reaction norms show percentage of cleavage stage embryos (A,B) and gastrulae (C,D) in experimental temperatures pooled for pH (A,C) and in experimental pH levels pooled for temperature (B,D). Lines represent the mean percentage of paternal half-siblings (n = 8 males). The eight male genotypes and standard errors are indicated.