Figure 2. Impacts of ocean acidification on sperm motility and sperm swimming speed in Heliocidaris erythrogramma.

Proportion of mean (±S.E.) motile sperm (A) and sperm speed (B) at different levels of ocean acidification (pH mediated by CO₂ addition). Lower case letters indicate significantly different groups at p = 0.05 (Tukey’s test). (C) Mean logarithmic response ratios (±95% CI) of effects of ocean acidification on percent motility and sperm speed (n = 19).