OVARIAN DEVELOPMENT AND REPRODUCTIVE CYCLE OF GARRA GOTYLA GOTYLA

Abstract

Garra gotyla gotyla is one of the important fish of Jhajjar stream, J&K, India. The present study is aimed to determine the ovarian development and reproductive cycle of this fish. The histological sections of ovaries shows the presence of a large number of oogonia and oocytes in various stages of development, studded along ovigerous lamellae. Based on changes in cytoplasm and its inclusion like vesicles, vitellogenesis, egg membranes and average diameter of oocytes, seven oocyte stages have been recorded viz. Oocyte stage I/ Chromatin nucleolar stage, Oocyte stage II/ Perinucleolar stage, Oocyte stage III/ Early yolk vesicle stage, Oocyte stage IV/ Late yolk vesicle stage, Oocyte stage V/Early yolk stage, Oocyte stage VI/ Late yolk stage and Oocyte stage VII/ Ripe egg stage. Further depending upon the percentage of different developing oocytes and nature of ovarian wall six phases of reproductive cycle has been observed. Immature/ virgin phase (September-October), early maturing phase (November-January), developing phase (February-March), developed phase (April-May), spawning phase (June- July) and spent/ resting phase (August). Gonadosomatic index (GSI) also exhibited remarkable variation during different phases of reproductive cycle and peak was observed during May. Present study therefore suggested that reproductive cycle of G. gotyla gotyla follows a cyclic pattern and exhibit remarkable histomorphological changes in ovaries as observed in other teleosts.