Journal article
Exposure to thyroid hormone in ovo affects otolith crystallization in rainbow trout Oncorhynchus mykiss
Environmental biology of fishes, Vol.95(3), pp.347-354
11/2012
Handle:
https://hdl.handle.net/2376/115135
Abstract
Calcareous otoliths in the inner ears of fishes are necessary for proper hearing and vestibular function. Sagittal otoliths are usually composed of the calcium carbonate polymorph aragonite but may contain the polymorph vaterite, a phenomenon called otolith crystallization. The causes of otolith crystallization are poorly understood. Thyroid hormone (TH) can influence the chemical microenvironment and structure of the inner ear, suggesting that TH may influence otolith crystallization. The present study examined the effect of exogenous TH treatment on sagittal otolith crystallization and growth in larval and juvenile rainbow trout, Oncorhynchus mykiss. In the first experiment, 110–179 day-old fish raised from TH-treated oocytes had significantly fewer sagittal otoliths containing the crystalline calcium carbonate polymorph vaterite as compared to untreated fish. Vaterite-containing otoliths were significantly longer than those containing the typical polymorph aragonite, although there was no effect of TH treatment on otolith length. In the second experiment, juveniles immersed in an exogenous solution of TH for 6 weeks had slightly longer otoliths (relative to fish length) than age-matched controls, but this effect was not significant. This juvenile population had a very high percentage (88.3 %) of vaterite sagittae overall and this percentage did not change significantly with treatment, suggesting the switch from aragonite to vaterite occurred prior to inclusion of the fish in the study. These results suggest that early manipulation of TH levels may affect calcium carbonate deposition on the otolith but that later TH exposure is unable to restore typical otolith composition.
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Details
- Title
- Exposure to thyroid hormone in ovo affects otolith crystallization in rainbow trout Oncorhynchus mykiss
- Creators
- Allison Coffin - Neuroscience Program Washington State University Vancouver WA 98686 USAJason Raine - Toxicology Centre University of Saskatchewan Saskatoon Saskatchewan Canada S7N 5B3Craig Hawryshyn - Department of Biology Queen’s University Kingston Ontario K7L 3N6 Canada
- Publication Details
- Environmental biology of fishes, Vol.95(3), pp.347-354
- Academic Unit
- Integrative Physiology and Neuroscience, Department of
- Publisher
- Springer Netherlands; Dordrecht
- Identifiers
- 99900547824301842
- Language
- English
- Resource Type
- Journal article