Fig. 4From: Breeding system, shell size and age at sexual maturity affect sperm length in stylommatophoran gastropodsEffect of age at sexual maturity on sperm length in gastropods. Phylogenetic effects and the influence of the breeding system have been taken into account. Bars indicate mean values, whiskers standard errors. Different letters indicate significant differences between age groups (Tukey test, p-value adjusted following Westfall [115]). Sample sizes are 5, 18 and 34 from left to rightBack to article page