作者: Sidney L. Tamm
DOI: 10.1086/BBLV227N1P7
关键词:
摘要: The aboral sensory organ (apical organ) of ctenophores contains a statocyst with single large statolith. statolith comprises living cells (lithocytes), each containing membrane-bound concretion. is supported on the distal ends four compound motile mechanoresponsive cilia (balancers) which control beat frequencies eight locomotory comb rows, and thereby orientation animals to gravity. In Mnemiopsis leidyi Pleurobrachia pileus, lithocytes arise in thickened epithelial floor apical opposite sides along tentacular plane. Lithocytes progressively differentiate migrate toward surface where they bud off next bases balancers. New are transported up balancers by ciliary motility form (Noda, 2013). has superellipsoidal shape due rectangular arrangement addition new its via size increases animal size, starting at highest rate growth younger stages gradually decreasing larger animals. total number developing rapidly smaller reaches plateau range therefore produced continually throughout life for enlargement possibly turnover replacement existing lithocytes. dome enclosing were observed propagate slow, low-ampitude waves distally. may act as an undulating screen prevent foreign objects seawater from being non-specifically make defective