Data from: Asexual freshwater snails make poor mate choice decisions

Once-useful traits that no longer contribute to fitness tend to decay over
time. We address whether the expression of mating-related traits that
increase the fitness of sexually reproducing individuals but are likely
less useful or even costly to asexual counterparts seems to exhibit decay
in the latter. Potamopyrgus antipodarum is a New Zealand freshwater snail
characterized by repeated transitions from sexual to asexual reproduction.
The frequent coexistence of sexual and asexual lineages makes P.
antipodarum an excellent model for the study of mating-related trait loss.
We used a mating choice assay including sexual and asexual P. antipodarum
females and conspecific (presumed better choice) vs. heterospecific
(presumed worse choice) males to evaluate the loss of behavioural traits
related to sexual reproduction. We found that sexual females engaged in
mating behaviours with conspecific mating partners more frequently and for
a greater duration than with heterospecific mating partners, while asexual
females seemed to lack the ability to make a choice. These results suggest
that selection acting to maintain mate choice in asexual P. antipodarum is
weak or ineffective relative to sexual females and that asexual
reproduction likely contributes to the evolutionary decay of behavioural
traits in this system.