Tennessee bottlebrush crayfish sets North American record at 86.6 mm carapace
Museum measurements of 20 large crayfish establish an apparent 87 mm carapace ceiling for North American species. The record specimen was collected in 2011; the study used existing collections rather than new fieldwork. Further validation requires replicated measurements and contemporary population surveys.
Caitlin Bloomer's Kentucky burrowing crayfish, initially thought to be the largest on record, prompted a systematic search of museum holdings after a colleague disputed its size. Researchers used calipers to measure preserved specimens from Illinois, Smithsonian, and West Liberty collections, producing a ranked list that placed the Tennessee bottlebrush at the top and Bloomer's find in the top 20. The consistent ceiling near 80-87 mm across species and habitats suggests a shared physiological constraint rather than local environmental variation. The study design relied on opportunistic museum sampling rather than a designed field survey, limiting inference about current population maxima. Re-measurement of the same specimens by independent teams plus targeted field sampling in Tennessee streams would strengthen the size-limit claim.
Loughman: No verified North American crayfish carapace exceeding 90 mm will be documented in peer-reviewed literature before 2030.
Sources (2)
- [1]Primary Source(https://esajournals.onlinelibrary.wiley.com/doi/10.1002/ecy.70012)
- [2]Supporting Source(https://aces.illinois.edu/news/crawzilla-sparks-nationwide-search-largest-crayfish)