Comparison of Two Crayfish Trapping Methods in Coastal Plain Seasonal Wetlands
We compared crayfish collections from minnow versus microhabitat traps in the Dahomey National Wildlife Refuge, Bolivar County, Mississippi, USA, extending the knowledge of microhabitat trap effectiveness to seasonal bottomland hardwood forest floodplains. Crayfishes were captured in three seasonally flooded habitat types: wooded, trail, and open habitats. The CPUE of vernal crayfish Procambarus viaeviridis and White River crayfish P. acutus was higher in minnow traps, whereas CPUE of swamp dwarf crayfish Cambarellus puer was higher in microhabitat traps. The CPUE did not differ among habitat types for either trap type. In minnow traps, CPUE of vernal and White River crayfishes increased steadily during the study, whereas CPUE of swamp dwarf crayfish did not vary over time. In microhabitat traps, CPUE did not vary over time for any species. Microhabitat traps were more effective at collecting adult, female vernal crayfish in the winter than spring, whereas minnow traps were more effective at collecting adult, female vernal crayfish in the spring than winter. Form I males of all three species were collected in both trap types throughout the study, whereas the only ovigerous females collected were swamp dwarf crayfish. Microhabitat traps caught more small crayfishes, pertinent to studies of population structure and recruitment, and were more effective at collecting adult swamp dwarf crayfish, a species five times smaller than other collected species. Conversely, minnow traps provided a better understanding of abundances and population structures of larger crayfishes. Using both trap types provided data on all size classes and life stages and reduced sampling selectivity.