Gonadal Histological Study of Oyster (Crassostrea sp) Collected from the South-East Coast of Bangladesh

Abstract

The edible oyster (Crassostrea sp.) is one of the world's most promising mariculture shellfish species which is bound in the coastal belt of Bangladesh especially along the Cox’s Bazar coast. For development of oyster culture technology, understanding the reproductive biology of Crassostrea sp is required. The objective of this study is to use histology to properly identify the dynamic characteristics of gonadal development process. The study was conducted during March 2018 to February 2019 and a total of 240 oysters were taken from the Moheskhali Channel, Cox's Bazar. The collected samples were analyzed for total length, total weight, shell length and width, gonad weight and wet tissue weight. Length-Weight relationships showed negative allometric growth (b<3) GSI (gonadosomatic index) and histological analysis were done to determine the reproductive cycle. GSI value was found to be generally higher in female than male. The percentage of the male was 30% where the female was 70%. The study confirmed that the spawning of Crassostrea sp. occurred twice during one year study from March 2018 to February 2019. In case of males, two peaks were reported during June and November, whereas, for females, July and December indicated as peak mature stage. The finding of this study would be beneficial for managing naturally occurring oyster stocks and developing future aquaculture aspects in the coastal belt of Bangladesh