Authors : K.B Nagarnaik
Page Nos : 193-198
Description :
A pair of large ovaries are situated on either side of the alimentary canal occupying most of the abdominal cavity. Each ovary is composed of large number of ovarioles. The ovarioles are differentiated Antero posteriorly into four regions: terminal filament, germarium, vitellarium and pedicel. The vitellarium consists of a series of developing oocytes in linear fashion, each accompanied with a group of 15 nurse cells and thus representing polytropic – Meroistictype. The terminal oocyte undergo development through a series of consecutive 5 vitellogenic stages such as pre,early,mid,late and maturational stages.The deposition of yolk starts at the early vitellogenic stage dyring which transport of fine granules from follicular cells to the oocyte is well evident. During mid and late vitellogenic stages the oocyte grows in size and filled with the yolk bodies. The nusrse cells initially transport RNA to the vitellogenic oocyte and undergo degeneration prior to late vitelogenic stage. Thye histochemical and biochemical studies show protein lipid and carbohydrate composition of yolk material.
