Semi-Quantitative Methods for Crayfish Sampling: Sex, Size, and Habitat Bias

We evaluated the effectiveness of four sampling methods for freshwater crayfish in five aquatic habitat types in Congaree National Park, South Carolina, USA. Electrofishing was the most successful technique in terms of the diversity of species collected, the number of individuals collected, and the widest range of sizes collected. Seine netting was the next most successful method. Baited minnow traps were biased towards form I males and larger individuals, while dip netting was biased towards smaller individuals. The relative success of techniques depended somewhat upon species. For two stream dwelling species, Procambarus acutus and P. chacei, electrofishing collected significantly more individuals than any other technique. For P. troglodytes, the most abundant species and a habitat generalist, electrofishing was superior to dip netting in some habitats, but did not significantly differ from traps or seine netting. For Fallicambarus fodiens, no significant differences among the effectiveness of any sampling methods were detected.