• DOI:10.4319/lo.2004.49.5.1857
• Corpus ID: 85991459

Testing a selective tidal‐stream transport model: Observations of female blue crab (Callinectes sapidus) vertical migration during the spawning season

@article{Hench2004TestingAS,
  title={Testing a selective tidal‐stream transport model: Observations of female blue crab (Callinectes sapidus) vertical migration during the spawning season},
  author={James L. Hench and Richard B. Jr. Forward and Sarah D. Carr and Dan Rittschof and Richard A. Luettich},
  journal={Limnology and Oceanography},
  year={2004},
  volume={49}
}

• J. Hench, R. Forward, +2 authors R. A. Luettich
• Published 1 September 2004
• Environmental Science, Biology
• Limnology and Oceanography

With field, laboratory, and modeling approaches, we examined the interplay among habitat structure, intraguild predation (IGP), and parasitism in an ongoing species invasion. Native Gammarus duebeni celticus (Crustacea: Amphipoda) are often, but not always, replaced by the invader Gammarus pulex through differential IGP. The muscle‐wasting microsporidian parasite Pleistophora mulleri infects the native but not the invader. We found a highly variable prevalence of P. mulleri in uninvaded rivers, with 0–91% of hosts parasitized per sample. In addition, unparasitized natives dominated fast‐flowing riffle patches of river, whereas parasitized individuals dominated slower‐flowing, pooled patches. We examined the survivorship of invader and native in single and mixed‐species microcosms with high, intermediate, and zero parasite prevalence. G. pulex survivorship was high in all treatments, whereas G. duebeni subsp. celticus survivorship was significantly lower in the presence of the invader. Further, parasitized G. duebeni subsp. celticus experienced near‐total elimination. Models of the species replacement process implied that parasite‐enhanced IGP would make invasion by G. pulex more likely, regardless of habitat and parasite spatial structure. However, where heterogeneity in parasite prevalence creates a landscape of patches with different susceptibilities to invasion, G. pulex may succeed in cases where invasion would not be possible if patches were equivalent. The different responses of parasitized and unparasitized G. duebeni subsp. celticus to environmental heterogeneity potentially link landscape patterns to the success or failure of the invasion process.