الفهرس 
Reproductive biologyOnly 14 pages are availabe for public view
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Abstract
The rabbitfish, Siganus rivulatus was choosen for the present study for two reasons (1) its popularity among coastal inhabitants of Egypt, (2) as a good candidate for mariculture in Egypt where it is a herbivorous fish. The present study was carried out in the following directions: The reproductive biology of the fish and the environmental factors affect the breeding. The histological structure of the pituitary gland to study the different cell types in the gland. The histological examination of the gonads (oogenesis and spe~matogenesis), and the correlation between the activity of the gonads and the pituitary GTH cells( and hepatic cells in female fish). According to the morphological changes that occurred in the gonads of Siganus rivulatus , the maturity stages of the gonads were classified into the following stages : thread, immature, maturation, nearly ripe, spawning and spent, For the females and males the maturity stages were clearly separated due to the obvious changes in size and colour of the ovaries and the testes in the different stages. The monthly distribution of maturity stages revealed that the spawning season is relatively short, it started in early June and was terminated in mid July. The study of length and age at first sexual maturity showed that the male fish of total length < 18 cm were immature, while female fish of total length <19 cm were immature. All the fish > 22.9 cm were sexually mature, and the age of these fish ranged from 3 to 4 years.