Ribelin Ben W, Collier Albert
Department of Biological Science, Florida State University, Tallahassee, Florida 32306.
J Morphol. 1977 Mar;151(3):439-449. doi: 10.1002/jmor.1051510308.
Latero-frontal, para-latero-frontal, and frontal ciliary tracts on the gill filaments of Crassostrea virginica (Gmelin) were studied with light microscopy and scanning electron microscopy. Latero-frontal cirri are complex structures composed of varying numbers of paired cilia. The multiple pairs of cilia which constitute a single cirrus are closely appressed for a portion of their length; they then branch laterally from the central axis in a plume-like fashion. Latero-frontal cirri of adjacent gill filaments create a filtration sieve which should be capable of retaining particles smaller than 1 μm in diameter. Para-latero-frontal cilia are short, closely spaced cilia arranged as a staggered row along the frontal side of each tract of latero-frontal cirri. Latero-frontal cirri and para-latero-frontal cilia occur on ordinary, principal, and transitional gill filaments. Frontal ciliary tracts of ordinary filaments are divided into a central, ventrally directed coarse tract, flanked on either side by a dorsally directed fine ciliary tract. The coarse tract is covered by cirri which are comprised of five to eight cilia, while the fine frontal tracts are made up of individually functioning cilia. The frontal ciliary tracts of principal and transitional filaments bear only dorsally directed fine cilia. The unique direction of effective beat of the coarse frontal cirri of ordinary filaments, in combination with the action of fine frontal cilia and the strategic location of mucus producing cells, is used to describe a possible mechanism for the sorting of filtered particles.
利用光学显微镜和扫描电子显微镜对弗吉尼亚牡蛎（Gmelin）鳃丝上的侧额叶、旁侧额叶和额缘纤毛束进行了研究。侧额叶触须是由不同数量的成对纤毛组成的复杂结构。构成单个触须的多对纤毛在其长度的一部分紧密贴合；然后它们以羽状方式从中心轴横向分支。相邻鳃丝的侧额叶触须形成一个过滤筛，应该能够保留直径小于1μm的颗粒。旁侧额叶纤毛短，间隔紧密，沿着每束侧额叶触须的额叶侧以交错排排列。侧额叶触须和旁侧额叶纤毛出现在普通、主要和过渡性鳃丝上。普通鳃丝的额缘纤毛束分为中央腹侧粗束，两侧各有一个背侧细纤毛束。粗束被由五到八根纤毛组成的触须覆盖，而细额束由单独起作用的纤毛组成。主要和过渡性鳃丝的额缘纤毛束仅带有背侧细纤毛。普通鳃丝粗额触须独特的有效搏动方向，结合细额纤毛的作用和产生黏液细胞的战略位置，被用来描述一种过滤颗粒分选的可能机制。
