Jenkins D B
Am J Anat. 1979 Jan;154(1):81-101. doi: 10.1002/aja.1001540106.
The sacculi of five species of catfishes were studied by transmission and scanning electron microscopy. In four species, the sagitta exhibited a multifluted anterior part and a tapered posterior part; in Corydoras aeneus, however, the fluted part was absent, and a vertical component extended dorsally to terminate near the opening of the transverse canal. In all species, the otoliths had a laminar structure. An otolithic membrane was present, and hair cell bundles projected into cavities on the macular surface of the membrane. Attachments of the otolithic membrane to the neuroepithelium included short extensions of the membrane to the tallest components of the hair cell bundles of the peripheral cells and more delicate connections to the kinocilium and taller stereocilia of central cells; in addition, attachments to the microvilli of supporting cells were present. In both hair cells and supporting cells single microtubules and bundles of microtubules were present; the bundles had an orderly arrangement and were associated with cytoplasmic densities surrounding the desmosomes. The hair cells were innervated by both afferent and efferent nerve endings. Studies of the polarization of the hair cells in all species (except C. aeneus) showed that there was a single longitudinal axis that divided dorsally polarized cells from those oriented ventrally. In Doras spinosissimus and Bunocephalus bicolor, an additional line of polarization was evident in a small area in the anterior part of the macula; therefore, in these forms there was a double bipolar orientation.
通过透射电子显微镜和扫描电子显微镜对五种鲶鱼的球囊进行了研究。在四种鲶鱼中，矢耳石前部呈多褶状，后部呈锥形；然而，在青铜兵鲶中，没有褶状部分，一个垂直部分向背侧延伸至横管开口附近终止。在所有物种中，耳石都具有层状结构。存在耳石膜，毛细胞束投射到膜黄斑表面的腔中。耳石膜与神经上皮的附着包括膜向周围细胞毛细胞束最高成分的短延伸，以及与中央细胞动纤毛和较高静纤毛的更精细连接；此外，还存在与支持细胞微绒毛的附着。在毛细胞和支持细胞中都存在单根微管和微管束；这些微管束排列有序，并与围绕桥粒的细胞质致密物相关。毛细胞由传入和传出神经末梢支配。对所有物种（除青铜兵鲶外）毛细胞极化的研究表明，存在一条单一的纵轴，将背侧极化细胞与腹侧极化细胞分开。在多棘铲鲟和双色兵鲶中，在黄斑前部的一个小区域内明显存在另一条极化线；因此，在这些形态中存在双极取向。
