The proportion of eggs that only partially developed across the mating pair types. In each combination, female species is denoted by the first letter, and male species by the second. Data are displayed as medians (thickened line) and inter-quartile ranges (grey boxes), circles are outlying values. While BB and CC mating pairs do not differ in the proportion of eggs that only partially develop, heterospecific (BC) mating pairs differ from the conspecific (BB & CC) mating pairs. Statistical significance: NS P > 0.05; ** P < 0.01.