Abstract
We provide up-to-date morphological and compositional data on otoliths of the osteoglossomorph Goldeye (Hiodon alosoides). Using computed tomography (CT) X-ray, we documented the location of each of the three pairs of otoliths (lapilli, sagittae, and asterisci) in relation to the swim bladder, which extended forward in close proximity to the sagittae and asterisci. The lappili were the largest otoliths in terms of surface area and volume, but the sagittae were highly modified, appearing spiral in shape when viewed dorsally, with a surface area to volume ratio more than double that of the lapilli. Using scanning electron microscopy, the surface of each otolith was viewable in great detail, and small otoconia (~10.5 μm diameter) were observed on each, but were most numerous on the sagittae. On scanning electron micrographs, the sagittae appeared to be bi-lobed, with asymmetrical lobes each oriented in the same general direction. Using neutron and X-ray diffraction methods, we found three polymorphs of calcium carbonate crystals (aragonite, vaterite, and calcite), sometimes all within the same otolith. However, in general, lapilli and sagittae were composed predominately of aragonite whereas asterisci were composed chiefly of vaterite. With these results, we provide information on a unique species, whose inclusion in future studies would benefit our understanding of fish hearing, fish evolution, and fisheries ecology.
| Original language | English |
|---|---|
| Pages (from-to) | 511-519 |
| Number of pages | 9 |
| Journal | Journal of Morphology |
| Volume | 282 |
| Issue number | 4 |
| DOIs | |
| State | Published - Apr 2021 |
Funding
The authors thank J. Maisano and M. Colbert at the University of Texas for CT X-ray scanning and L. Whitworth at Oklahoma State University for SEM use. A portion of this research used resources at the Spallation Neutron Source, a DOE Office of Science User Facility operated by the Oak Ridge National Laboratory. The Oklahoma Cooperative Fish and Wildlife Research Unit works in collaboration with U.S. Geological Survey, Oklahoma State University, Oklahoma Department of Wildlife Conservation, Wildlife Management Institute, and U.S. Fish and Wildlife Service. Any use of trade, firm, or product names is for descriptive purposes only and does not imply endorsement by the U.S. Government.
| Funders | Funder number |
|---|---|
| U.S. Government | |
| Wildlife Management Institute | |
| U.S. Fish and Wildlife Service | |
| U.S. Geological Survey | |
| Office of Science | |
| Oak Ridge National Laboratory | |
| Oklahoma State University | |
| Oklahoma Department of Wildlife Conservation | |
| Idaho Cooperative Fish and Wildlife Research Unit, University of Idaho |
Keywords
- Osteoglossomorpha
- carbonate polymorph
- inner ear connection
- otoconia
- swim bladder