U.S. Geological Survey, Oklahoma Cooperative Fish and Wildlife Research Unit, Department of Natural Resource Ecology and Management, Oklahoma State University, Stillwater, Oklahoma, USA.
Oklahoma Department of Wildlife Conservation, Oklahoma Fishery Research Laboratory, Norman, Oklahoma, USA.
J Morphol. 2021 Apr;282(4):511-519. doi: 10.1002/jmor.21324. Epub 2021 Feb 1.
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.
我们提供了骨舌鱼目金眼鲷（Hiodon alosoides）耳石的最新形态和组成数据。使用计算机断层扫描（CT）X 射线，我们记录了三对耳石（小石砾、矢耳石和星耳石）中每一对相对于鳔的位置，鳔向前延伸，与矢耳石和星耳石紧密相邻。小石砾在表面积和体积方面是最大的耳石，但矢耳石高度变形，从背面看呈螺旋状，表面积与体积的比值是小石砾的两倍多。使用扫描电子显微镜可以非常详细地观察每个耳石的表面，并且在每个耳石上都观察到了小耳石（直径约 10.5 μm），但在矢耳石上最多。在扫描电子显微镜照片上，矢耳石似乎呈双叶状，不对称的叶瓣每个都朝向大致相同的方向。使用中子和 X 射线衍射方法，我们发现了三种碳酸钙晶体的多晶型（霰石、方解石和文石），有时在同一个耳石中都有。然而，总体而言，小石砾和矢耳石主要由霰石组成，而星耳石主要由方解石组成。有了这些结果，我们提供了有关一个独特物种的信息，将其纳入未来的研究将有助于我们理解鱼类听力、鱼类进化和渔业生态学。
