Data from: Differences in parasite infection status and behavior between a clonal fish and her sexually reproducing heterospecifics

Parasites impose strong selective pressures on animals, influencing traits
from behavior to reproductive strategies. In particular, parasite-mediated
selection has been proposed as a major driver of sexual reproduction, as
genetic recombination can generate variation that facilitates rapid
evolutionary responses to parasites. Accordingly, asexual vertebrates are
predicted to be more susceptible to parasites, yet some persist over
longer than expected evolutionary timescales. The Amazon molly (Poecilia
formosa) is a gynogenetic, clonal fish that occurs sympatrically with its
sexual parental species, including the Sailfin molly (P. latipinna). Here,
we investigate the link between behavioral differences and parasite
infection in wild-caught Amazon and Sailfin mollies across two
populations. Fish were exposed to a simulated predator attack, and
space-use behavior was quantified as time spent in open versus sheltered
areas. We subsequently determined their infection status and parasite load
via dissection. We found that Amazons and Sailfins differed in their
qualitative, but not quantitative, resistance to parasites. Amazons had
worse qualitative resistance (i.e., were more likely to be infected with
at least one parasite) and spent more time in the open, riskier portion of
the arena. However, consistent with previous studies, Amazons and Sailfins
did not differ in quantitative resistance (i.e., parasite load). Parasite
prevalence and load differed between our two collection sites, suggesting
an important role for environmental context. These results suggest that
there is a correlation between behavior and parasite exposure in Amazons,
while immune or physiological traits may allow them to limit parasite
loads once infected. While the scope of this study makes it difficult to
tell whether increased risk-taking behavior leads to parasite exposure or
vice versa, our results still highlight important differences between
sexual and asexual species in parasite-laden environments.