Research

Systematic revision of the crayfish genus Lacunicambarus

The goal of my Ph.D. dissertation is to investigate the crayfish genus Lacunicambarus using molecular systematics and morphometrics. The most iconic member of this complex is the Devil Crayfish, Lacunicambarus diogenes (Girard 1852). Historically, all burrowing crayfishes that resembled the Devil Crayfish have been labeled as such. This lack of taxonomic resolution has led to the Devil Crayfish sensu lato being one of the most widespread crayfishes in North America. However, it has long been suspected that the Devil Crayfish represents a species complex and in recent years, a handful of species have been described from within this complex. Further teasing apart the Devil Crayfish complex is important because some of the species within it may have actually have relatively small ranges and require differential conservation attention.

June 2020 update: My collaborators Susie Adams, Zac Loughman, Greg Myers, Chris Taylor, Guenter Schuster and I just described two new species of Lacunicambarus burrowing crayfish species from Alabama and Mississippi! This project started started when Chris and Guenter sent me tissues samples from specimens they collected during a survey for the Rusty Gravedigger, Lacunicambarus miltus, that they conducted a decade ago. I extracted DNA from these tissue samples and included them in my phylogenetic analyses of Lacunicambarus and found that they were related to L. miltus, but seemed to have diverged considerably. We didn't have enough data to make any firm conclusions, so we went into the field to get more samples in early 2020. We collected specimens of the species that is related to L. miltus, which we eventually described and named the Lonesome Gravedigger, L. mobilensis, as well as specimens of a species that Chris and Guenter had collected once but that we knew virtually nothing about. We called the latter the Banded Mudbug, and named it L. freudensteini after my co-advisor Dr. John Freudenstein at Ohio State University. We published this work in Zootaxa.

October 2019 update: My collaborators Dr. Zac Loughman and Dr. Bronwyn Williams and I just described a new species called the Jewel Mudbug, Lacunicambarus dalyae! We named this species after Dr. Meg Daly of The Ohio State University to recognize all that she has done to help get my dissertation research off of the ground. The Jewel Mudbug is found throughout the southeastern United States. It resembles the Paintedhand Mudbug, L. polychromatus, but has a very different gonopod. This is the most beautiful crayfish that I have encountered to date, and I am very excited to have had the opportunity to name it! Our manuscript in Zootaxa is free to download!

January 2019 update: My collaborators and I just published the description of a new species, Lacunicambarus chimera, that we split off from the Devil Crayfish, L. diogenes. In our paper, which is free to download from Zootaxa, we use both molecular and morphometric techniques to differentiate these two species. We also present all of the information we have about the ecology of this new species and discuss its coloration, range, and much more. A few more species that were previously lumped into the Devil Crayfish still need to be described before this complex is fully resolved. Stay tuned for more updates in 2019!

August 2018 update: My collaborators and I just published the first major findings of this taxonomic revision in the Journal of Crustacean Biology! We have made the following taxonomic changes:

Elevated the subgenus Lacunicambarus to generic rank and redescribed it to encompass all but one of the species that were previously in the subgenera Lacunicambarus and Tubericambarus. The sole exception is Cambarus stockeri, which remains in Cambarus. We provide a key to the currently described species of Lacunicambarus in our paper.
Redescribed the Devil Crayfish, Lacunicambarus diogenes. In the process of doing so doing so, we designated a neotype (pictured right) for the species, as the previous one was destroyed in the Great Chicago Fire of 1871.
Restricted the range of this species to the east coast of the United States. We suggest that "Devil Crayfish" that occur outside of the restricted range be provisionally referred to as Lacunicambarus aff. diogenes until they are examined and described, which is already underway!

L. diogenes neotype. Photo by G. Schuster.