Figure 4.8 Snail responses to variation in mates. In the common pond snail, mate availability can vary a great deal. (a) Snails raised without mates wait nearly 2 weeks before self-fertilizing their eggs. (b) Snails without mates produce fewer progeny compared to snails with mates, but this strategy is more fit than foregoing all reproduction. Error bars are standard errors.
After A. Tsitrone et al., Delayed selfing and resource reallocations in relation to mate availability in the freshwater snail Physa acuta, American Naturalist 162 (2003): 474–488.