The effect of Melastoma malabathricum leaf extract on growth and spawning of blue swimming crab (Portunus pelagicus)

Abstract

The aim of this study was to evaluate the effect of Melastoma malabathricum leaf extract on growth and spawning of the blue swimming crab Portunus pelagicus. This research was conducted from March to May 2019 at the Hasanuddin University mini hatchery in Barru Regency, South Sulawesi Province, Indonesia. The study used five treatment doses of M malabathricum leaf extract: 0, 5, 10, 15, and 20μg/g of female crab body weight. The extract was dissolved in water and an aliquot of 0.1 mL was injected into each crab. The results showed that there was a decrease in growth in all treatments within the first 10 days after injection, but an increase after the 20th day. Doses of 15 and 20 ug/g resulted in the highest spawning rate, ie 100% after 30 days. Crabs with no extract treatment had the lowest spawning rate, which was only 33%. The conclusion of this study is that an appropriate dose of M. malabathricum leaf extract can be used to stimulate spawning of Portunus pelagicus.