Histological studies on the gonads of the Indian scad Decapterus russelli (Ruppell, 1830) from Maharashtra waters, north-west coast of India

Histological studies on the gonads of Decapterus russelli were undertaken to understand the mode of gonad development and to describe the maturity stages. Based on the histological studies, six stages of oocyte development were identified. Histological sections revealed that ovarian development in D. russelli is of asynchronous type. The presence of many large yolk vacuoles in the cytoplasm of oocytes indicated pelagic nature of the eggs. Maturation of sperm occurs along the entire length of the seminiferous tubules and was found to be unrestricted spermatogonial testis. Within each seminiferous tubule, cysts containing germ cells at different stages of development were seen; however germ cells within each cyst were at the same stage of development. This is the first report on the gonadal development of D. russelli from Indian waters.