Zhang Z
School of Biological Science, University of Wales Bangor, Gwynedd LL57 2UW, United Kingdom.
J Morphol. 1992 Feb;211(2):213-220. doi: 10.1002/jmor.1052110210.
An otolith increment is composed of an incremental zone and a discontinous zone. Observation of the otoliths of Oreochromis niloticus with transmission and scanning electron microscopy reveals that organic fibers are concentrated in the discontinuous zone and are relatively scarce in the incremental zone. On the other hand, calcium carbonate crystals are chiefly packed in the incremental zone and are less dense in the discontinuous zone. Both fibers and crystals are oriented perpendicular to the growth increments. Otolith checks, or discontinuities, contain even denser fibers and fewer fine crystals than does the discontinuous zone. A higher proportion of individual fibers is prominently stained in the discontinuous zone and check than in the incremental zone. Other features of individual fibers appear to be the same among the three zones. The crystals on either side of a check or a discontinuous zone resemble each other both in size and orientation. Zonation of protein and mineral components of otoliths can be understood in terms of both incremental growth and the daily cycle of deposition.
耳石增量由一个增量区和一个间断区组成。利用透射电子显微镜和扫描电子显微镜对尼罗罗非鱼的耳石进行观察发现，有机纤维集中在间断区，在增量区相对较少。另一方面，碳酸钙晶体主要堆积在增量区，在间断区密度较小。纤维和晶体均垂直于生长增量方向排列。耳石检查或间断处所含的纤维比间断区更密集，细晶更少。间断区和检查处的单个纤维中，有较高比例的纤维被显著染色，高于增量区。单个纤维的其他特征在这三个区域中似乎是相同的。检查处或间断区两侧的晶体在大小和取向上彼此相似。耳石蛋白质和矿物质成分的分层可以根据增量生长和每日沉积周期来理解。
