1. The responses of starfish sperm flagella to mechanical stimulation with a microneedle were analysed. Flagellar movement was recorded by high-speed microcinematography and by stroboscopic observation. 2. The amplitude of the bending wave of a flagellum was restricted over its entire length when the microneedle was brought near to the flagellum at its proximal region. Beyond the restricted par...

1. Exposure of unfertilized starfish eggs to dilute solutions of weak acids (fatty acids, benzoic and carbonic acids) in isotonic balanced salt solution causes complete activation with the proper durations of exposure. For each acid the rate of activation (reciprocal of optimum duration) varies with concentration and temperature; at a given temperature and within a considerable range of concent...

In contrast to the somatic cell cycle, duplication of the centrioles does not occur in the second meiotic cycle. Previous studies have revealed that in starfish each of the two centrosomes in fully-grown immature oocytes consists of two centrioles with different destinies: one survives and retains its reproductive capacity, and the other is lost after completion of meiosis. In this study, we in...

Four new polyhydroxysteroidal glycosides-culcinosides A-D (1, 2, 4, and 7)-along with three known compounds-echinasteroside C (3), linckoside F (5), and linckoside L3 (6)-were isolated from the ethanol extract of starfish Culcita novaeguineae collected from the Xisha Islands of the South China Sea. The structures of new compounds were elucidated through extensive spectroscopic studies and chemi...

Centrioles from spermatozoa of the starfish, Asterina pectinifera, were isolated and partially purified by solubilization of chromatin followed by sucrose density-gradient centrifugation. The ultrastructure of the isolated centriolar complex was investigated in whole mount preparations by electron microscopy. The complex unit was composed of a pair of centrioles and a pericentriolar structure, ...