Exploration of The Natural Extender for Dilution of Walking Catfish Clarias batrachus Sperm in Refrigerated Storage

Abstract

Walking catfish Clarias batrachus is a freshwaterr fish that has high economic value. Currently, the culture of this local catfish has been initiated in Indonesia, but the breeding technology has not been well developed. Therefore, this study aims to explore the type of natural extender for sperm preservation of local catfish C. batrachus so that it can support the development of its breeding technology, especially in remote areas. The research was conducted at the Hatchery Laboratory of the Faculty of Marine and Fisheries, Universitas Syiahh Kuala, Banda Aceh, Indonesia.. Four types of natural extenders were tested in this study, namely young coconut water, nira water, sugarcane water, and old coconut water. Completely randomized design method consisting of five treatments and three replications were used in this study. Sperm were diluted with each tested extender with a sperm dilution rate of 1:20 (sperm: extender, v/v), then stored at 4 °C. The motility and viability were monitored every 24 h interval for 6 days. The results showed that the natural extender significantly affected the motility, viability, and sperm fertility of walking catfish (P<0.05). Young coconut water produced higher motility and viability on all observation days. The higher sperm motility, viability, and egg fertility on the last day of the experiment were also found in sperm diluted in young coconut water, with values of 45.83%, 43.83%, and 41.50%, respectively. These values were significantly different from other types of extenders. Therefore, it is concluded that young coconut water is the most suitable natural extender for sperm preservation of local catfish at 4 °C.