Abstract
The chorion of eggs in the porgy, Pagrus major, was observed by transmission and scanning electron microscopy.During the breeding season.mature unfertilized eggs and eggs immediately after fertilization were used as materials.The materials were fixed in 2%glutalaldehyde (pH 7.2) and I tetroxide (pH 7.2) for 2 and 1 hours, respectively, according to the usual method for prepared samples.Using scanning electron microscopy.the micropyle apparatus and numerous pits were observed on the chorion surface.The micropyle apparatus consisted of well-defined spiral layers and seemed to be of the tunnel type.When observed by transmission electron microscopy, the longitudinal profile of the chorion was composed of two layers, a thick inner layer and a thin outer layer composing the pits.As a result of applying Lloyd's “mean crowding” to the number of pits, it can be concluded that the distribution appearance of pits has a uniform distribution pattern.
