Gastric mill age estimates for ringed crayfish Faxonius neglectus neglectus (Faxon) and the influence of temperature on band formation
Published Online: 4/15/2020
Abstract
Counting bands via the gastric mill is a potential direct approach for ageing crayfish; however, the validity of ageing crustaceans using the gastric mill is unknown. Our study objectives were to 1) compare gastric mill age estimates to a traditional aging technique, 2) compare ageing precision among the ossicles, and 3) examine the effects of temperature on gastric mill band formation. From 2017–2018, we collected 681 ringed crayfish Faxonius neglectus neglectus (Faxon) from ten Ozark Highland streams. Our length-frequency analysis reflected seven age classes, whereas gastric mill age estimates indicated individuals were up to 10 yr of age. The length-frequency analysis age estimates showed good congruence (± 1 yr) with age estimates from the gastric mill 78% of the time. The coefficient of variation (CV) of age estimates from gastric mill bands between our readers was 29.7%. Ageing precision was highest when using the zygocardiac ossicles (CV = 12.4%). Gastric mill age estimates for known age-1 crayfish from a thermally stable laboratory were not significantly different from one, whereas age estimates from a thermally varying laboratory were greater than one. Our results indicate molting frequency does not control gastric mill band formation, and temperature plays a role in band formation.
Supplemental Documents

Cited By
0 Citations:
How to Cite
Mouser JB, Glover J and Brewer SK. (2020). Gastric mill age estimates for ringed crayfish Faxonius neglectus neglectus (Faxon) and the influence of temperature on band formation. Freshwater Crayfish 25(1):59-67. doi: 10.5869/fc.2020.v25-1.059
Author Information
Shannon Brewer,* Natural Resources Ecology and Management , USGS/OSU, 007 Agriculture Hall, Stillwater , OK, USA74078. E-mail: shannon.brewer@okstate.edu
Joshua Mouser, NREM, Oklahoma Cooperative Fish and Wildlife Research Unit, 007 Agriculture Hall , Stillwater , Oklahoma, USA74078. E-mail: jbmouse@okstate.edu
Jason Glover, NREM, Oklahoma Cooperative Fish and Wildlife Research Unit, 007 Agriculture Hall , Stillwater , Oklahoma, USA74078. E-mail: jdglove@okstate.edu
Corresponding Author indicated by an *.
Publication History
Manuscript Submitted: 6/28/2019
Manuscript Accepted: 3/26/2020
Published Online: 4/15/2020
Published in Print: 4/30/2020
Funding Information
No specific funding statement is available for this article.