Whitear M
Z Mikrosk Anat Forsch. 1981;95(4):531-43.
Calamoichthys calabaricus possesses four types of epidermal secretory cell. Mucus is produced by the superficial epithelial cells and by goblet cells. Electron microscopical studies show that the other two types of unicellular gland present are structurally similar to the club cells and to the sacciform cells of teleost fish. The outer cytoplasm of the club cells contains filaments, coiled in spirals, which can be compared to the helical filaments previously described in club cells of eels, although they are less regularly arranged. Spiral filaments similar to those of Calamoichthys can be detected in some ostariophysan species studied by electron microscopy. The homologies of so-called club cells in various fishes are discussed. The lampreys and gadoids are now known not to have club cells; in eels the club cells contain a secretory vacuole in addition to cytoplasm with helical filaments. The club cells of ostariophysans have been distinguished, by some authors, as "alarm substance cells", but their cytological characteristics are so close to those of the club cells of Calamoichthys that, morphologically, they must be considered homologous. The sacciform cells are a separate type of unicellular gland; their fine structure in Calamoichthys is closely similar to that reported from certain teleost fish. In spite of the cell diversity, polypterid skin provides a model for a type of epidermis which is primitive in the actinopterygii.
卡拉巴柔骨鱼有四种表皮分泌细胞。黏液由表层上皮细胞和杯状细胞产生。电子显微镜研究表明，另外两种单细胞腺在结构上与硬骨鱼的棒状细胞和囊状细胞相似。棒状细胞的外细胞质含有呈螺旋状盘绕的细丝，这可以与先前在鳗鱼棒状细胞中描述的螺旋细丝相比较，尽管它们的排列不太规则。通过电子显微镜研究，可以在一些骨鳔鱼类中检测到与卡拉巴柔骨鱼类似的螺旋细丝。讨论了各种鱼类中所谓棒状细胞的同源性。现在已知七鳃鳗和鳕类没有棒状细胞；在鳗鱼中，棒状细胞除了含有带有螺旋细丝的细胞质外，还含有一个分泌泡。一些作者将骨鳔鱼类的棒状细胞区分为“警报物质细胞”，但其细胞学特征与卡拉巴柔骨鱼的棒状细胞非常相似，从形态学上看，它们必须被认为是同源的。囊状细胞是一种单独的单细胞腺类型；卡拉巴柔骨鱼中它们的精细结构与某些硬骨鱼中报道的非常相似。尽管细胞具有多样性，但多鳍鱼的皮肤为辐鳍鱼中一种原始类型的表皮提供了一个模型。
