Open AccessLocal site differences in survival and parasitism of periwinkles ( Littorina sitkana Philippi, 1846)
Author(s) -
AyalaDíaz Mónica,
Richardson Jean M. L.,
Anholt Bradley R.
Publication year - 2017
Publication title -
ecology and evolution
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.17
H-Index - 63
ISSN - 2045-7758
DOI - 10.1002/ece3.2708
Subject(s) - littorina , biology , snail , intertidal zone , gastropoda , ecology , mollusca , parasitism , zoology , host (biology)
The periwinkle, Littorina sitkana , is found throughout the intertidal zone, often in isolated subpopulations. The majority of trematode parasites use snails as intermediate hosts, and decreased survivorship is often observed in snails infected with trematodes. Sampling L. sitkana from four sites in Barkley Sound, British Columbia, Canada, we test the effects of parasitic infection on snail survival using maximum likelihood and Bayesian approaches using the software MARK and Win BUGS . We found that survival of periwinkles and trematode community composition differed among sites, but survival and trematode prevalence were uncorrelated. Win BUGS performed better than MARK in two ways: (1) by allowing the use of information on known mortality, thus preventing survival overestimation; and (2) by giving more stable estimates while testing the effect of body size on snail survival. Our results suggest that snail survival depends heavily on local environmental factors that may vary greatly within a small geographical region. These findings are important because the majority of experimental studies on survival are done on snails from a single location.