Document Type
Article
Publication Date
4-16-2024
Abstract
Age estimation methods have not been validated for many species. Thus, we focused this age estimation study on four species from central Texas: the Guadalupe Bass Micropterus treculii, Channel Catfish Ictalurus punctatus, Gray Redhorse Moxostoma congestum, and Redbreast Sunfish Lepomis auritus. Our objectives for each species were to (1) investigate whether increments form annually in otoliths, fin rays, or spines; (2) determine the seasonal timing of zone deposition in each calcified structure; and (3) compare age estimates between otoliths and fin rays or spines.
Fish were sampled from central Texas waters and injected with oxytetracycline (OTC) quarterly in 2021. In July 2022, otoliths and fin rays or spines were collected to determine whether the increments formed annually and to estimate age.
On average, two readers identified the correct number of annuli after the OTC mark in at least 95% of Gray Redhorse, Guadalupe Bass, and Redbreast Sunfish otoliths but in only 69% of Channel Catfish otoliths. However, the more experienced reader identified the correct number of annuli in at least 95% of otoliths from age‐2–4 Channel Catfish. Compared to otoliths, the correct number of annuli after the OTC mark was identified in a smaller percentage of fin rays or spines (47–62%). The probability of identifying the correct number of annuli after the OTC mark differed between the two readers for all spines and fin rays. Age difference plots revealed that age estimates based on fin rays or spines were either overestimated or underestimated compared to otolith‐based ages for all species.
We consider annual increment formation in otoliths to be validated for all age‐classes of Gray Redhorse, Guadalupe Bass, and Redbreast Sunfish examined and for ages 2–4 of Channel Catfish. Differences in correctness between readers were most likely due to differences in age estimation experience. Given the level of error observed in our study, caution is advised if using age estimates from unvalidated structures and species.
This article was published Open Access through the CCU Libraries Transformative Agreement Program. The article was first published in the North American Journal of Fisheries Management: https://doi.org/10.1002/nafm.10997
Recommended Citation
Pfennig, M.B., Crane, D.P., Smith, N.G., & Buckmeier, D.L. (2024). Age estimation and validation in otoliths, spines, and fin rays from four central Texas fishes. North American Journal of Fisheries Management, 44(3), 590–606. https://doi.org/10.1002/nafm.10997. Available at https://digitalcommons.coastal.edu/biology/11/
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This work is licensed under a Creative Commons Attribution 4.0 International License.