Morphological, histological and ultrastructural studies on the ovaries of Liza carinata from the suez bay in correlation with its reproductive cycle

Abstract

Liza carinata is considered as a common and economically important Mugilidae fish of the Red Sea. Knowledge of the gonadal cycle in fishes has a great importance in the successful management of fisheries. The present study was undertaken to gain more information about the morphological, histological and ultrastructural aspects of the ovaries of L. carinata during the different seasons of its reproductive cycle in the Suez Bay. The maturity stages of the ovaries of L. carinata can be classified into four stages, namely: the early post-spawning, late post-spawning, pre-spawning and spawning stages. Besides, L. carinata spawns from late September to late December. Moreover, the oogenesis of L. carinata is divided into seven stages. These stages are the oogonia, chromatin-nucleolar, early peri-nucleolar, late peri-nucleolar, vacuolated, early yolk globular and late yolk globular stages. In addition, the ovaries also contain the post-ovulatory structures and atretic follicles. The former are formed of the hypertrophied follicular cells after the discharge of the mature ovum, while the latter are formed as a result of the sudden cease growth of the oocytes. The present observations may help in understanding the strategy of reproduction of L. carinata in the Suez Bay that may help in its aquaculture.