NATURAL AND HUMAN-MEDIATED INTERACTIONS BETWEEN FRESHWATER CRABS AND CRAYFISH

Abstract

Interactions between freshwater crabs and crayfish can have notable impacts that extend from local to biogeographical scales. These interactions been linked to the natural distributions of both decapod taxa (and their overall allopatry), and could threaten native populations of freshwater crabs within habitats invaded by non-native crayfish species. Given the implications associated with natural and human-mediated interactions between freshwater crabs and crayfish, as well as the lack of empirical studies investigating inter-taxa interactions, this thesis aims to address this at varying scales—from global to regional to local. These studies involve the modeling of taxa richness and species distribution patterns (both spatially and temporally), in-situ field studies, and ex-situ behavioral experiments. Results of which indicate that while natural interactions between these decapods can allow populations to co-exist in the same habitat, human-mediated interactions have negative impacts on native crab populations (caused by predation and size associated competitive advantage).