Dunkelberger Dana G, Dean John Mark, Watabe Norimitsu
Electron Microscopy Center and Department of Biology, University of South Carolina, Columbia, South Carolina 29208.
Belle W. Baruch Institute for Marine Biology and Coastal Research and Department of Biology, University of South Carolina, Columbia, South Carolina 29208.
J Morphol. 1980 Mar;163(3):367-377. doi: 10.1002/jmor.1051630309.
The sagitta otolithic membrane of Fundulus heteroclitus consists of two different zones. A structured zone (gelatinous layer), which usually exhibits a reticulated or honeycomb-like architecture, is composed of tightly arranged fibrous material and covers only the sensory region of the macula. The gelatinous layer extends from the otolith surface to the tips of the sensory hairs, and probably functions primarily as a mechanoreceptor. The arrangement of this zone is closely associated with specific overlying structural features of the otolith surface and may also influence the pattern of mineral deposition to some degree. A nonstructured zone (subcupular meshwork) consists of fibers in very loose networks and covers both sensory and nonsensory regions of the macula. Over the sensory region, some of this fibrous material extends from the epithelial surface, through pores in the gelatinous layer, to the surface of the overlying otolith. In the nonsensory region, fibers of the subcupular meshwork are relatively more numerous and extend around the peripheral margin of the otolith. Evidence is presented which suggests that the fibrous material of the subcupular meshwork is incorporated into the otolith as an organic matrix constituent. New aspects on the ultrastructure of the otolith are presented and discussed.
底鳉的矢状耳石膜由两个不同区域组成。一个结构化区域（凝胶层），通常呈现出网状或蜂窝状结构，由紧密排列的纤维材料构成，仅覆盖黄斑的感觉区域。凝胶层从耳石表面延伸至感觉毛的尖端，可能主要起机械感受器的作用。该区域的排列与耳石表面特定的上层结构特征密切相关，并且在一定程度上可能也会影响矿物质沉积的模式。一个非结构化区域（杯状小体网状结构）由非常松散网络中的纤维组成，覆盖黄斑的感觉和非感觉区域。在感觉区域上方，一些这种纤维材料从上皮表面穿过凝胶层中的孔隙延伸至覆盖其上的耳石表面。在非感觉区域，杯状小体网状结构的纤维相对更多，并围绕耳石的周边延伸。文中给出的证据表明，杯状小体网状结构的纤维作为有机基质成分被并入耳石。文中还呈现并讨论了耳石超微结构的新方面。
