Watson G M, Mariscal R N
Tissue Cell. 1983;15(6):939-53. doi: 10.1016/0040-8166(83)90059-9.
TEM observations of catch tentacles revealed that the tentacle tip epidermis is filled with two size classes of mature holotrich nematocysts and a gland cell filled with electron-dense vesicles. Vesicle production is restricted to upper-middle and tentacle tip regions, whereas holotrich development occurs in the lower-middle and tentacle base regions. Thus, catch tentacles have a maturity gradient along their length, with mature tissues concentrated at the tentacle tip. Occasional feeding tentacle cnidae (microbasic p-mastigophores and basitrichs) and mucus gland cells occur in proximal portions of catch tentacles, but are phagocytized by amoeboid granulocytes and transported to the gastrodermis for further degradation. No feeding tentacle cnidae or mucus cells occur distally in catch tentacles. Unlike catch tentacles, feeding tentacles are homogeneous in structure along their length with enidocytes containing mature spirocysts, microbasic p-mastigophore or basitrich nematocysts distributed along the epithelial surface. Cnidoblasts are recessed beneath cnidocytes, occurring along the nerve plexus. Mucus gland cells and gland cells filled with electron-dense vesicles are present in feeding tentacles, distributed at the epithelial surface. Granular phagocytes are rare in the feeding tentacle tip, but common in the tentacle base.
对捕食触手的透射电子显微镜观察显示，触手尖端表皮充满了两种大小类别的成熟全毛类刺细胞以及一个充满电子致密小泡的腺细胞。小泡产生仅限于触手的中上部和尖端区域，而全毛类刺细胞的发育发生在触手的中下部和基部区域。因此，捕食触手沿其长度存在成熟度梯度，成熟组织集中在触手尖端。在捕食触手的近端偶尔会出现摄食触手刺丝囊（微基 p 型鞭毛刺丝囊和基位刺丝囊）和黏液腺细胞，但会被变形粒细胞吞噬并运输到胃皮进行进一步降解。在捕食触手的远端没有摄食触手刺丝囊或黏液细胞。与捕食触手不同，摄食触手沿其长度结构均匀，含成熟螺旋刺丝囊、微基 p 型鞭毛刺丝囊或基位刺丝囊的刺细胞分布在上皮表面。刺细胞母细胞凹陷于刺细胞之下，沿神经丛分布。黏液腺细胞和充满电子致密小泡的腺细胞存在于摄食触手，分布在上皮表面。颗粒吞噬细胞在摄食触手尖端很少见，但在触手基部很常见。
