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As North American crayfish biodiversity becomes increasingly imperiled, the ambiguous nature of the current taxonomic framework can impede conservation efforts. The taxonomy of the family Cambaridae Hobbs, 1942 has historically been based on morphology, but recent studies using molecular phylogenetic techniques have revealed taxonomic inconsistencies, including a polyphyletic Cambarus Erichson, 1846. We took a step towards increasing the taxonomic resolution of Cambaridae by investigating a group of primary burrowing crayfishes which were historically part of the Cambarus subgenera Lacunicambarus Hobbs, 1969 and Tubericambarus Jezerinac, 1993. This group, here called the devil crayfish group (DCG) because it includes the devil crayfish (Cambarus diogenes Girard, 1852), has a confusing taxonomic history and is in need of revision to inform conservation assessments. We tested the hypothesis that the DCG is monophyletic through phylogenetic analyses of mitochondrial DNA sequence data from multiple specimens of the eight DCG species and a broad sample of taxa representing approximately 70% of the species in what is currently recognized as Cambarus. Seven of the eight species from the DCG form a well-supported, monophyletic group that is distinct from the remainder of what has traditionally been recognized as Cambarus. Our analyses place the DCG as sister to a clade consisting of taxa from Creaserinus Hobbs, 1973, Faxonius Ortmann, 1905, and Barbicambarus Hobbs, 1969. Based on our results and on unique morphological and ecological characteristics, we split seven of the eight DCG species from Cambarus and elevate the subgenus Lacunicambarus to generic level to accommodate them. We redescribe Lacunicambarus and the devil crayfish sensu stricto (Lacunicambarus diogenes comb. nov.) and designate a neotype for the species to facilitate subsequent revisionary work. [ABSTRACT FROM AUTHOR]

Baited modified minnow traps are often used to collect rusty crayfish (Orconectes rusticus), an invasive species in many areas of North America. However, the use of baited traps as a collection gear for decapods has received considerable scrutiny. We designed a tank-experiment to determine if captured rusty crayfish exclude uncaptured rusty crayfish from baited traps. We found that significantly more crayfish were captured in traps where captured crayfish were immediately removed (experimental tanks) than in traps where crayfish were not immediately removed (control tanks). in addition, more small crayfish were captured in the experimental tanks. These results are consistent with a hypothesis that large and aggressive previously captured rusty crayfish exclude other, generally smaller, rusty crayfish from the trap. [ABSTRACT FROM AUTHOR]