Preliminary study of closed system transportation, rearing and observation of the eggs Oryzias javanicus (Bleeker 1854) from Tunda Island

Abstract

Wild Oryzias javanicus from Tunda Island has potential as a native Indonesian aquatic ornamental fish and a model for research in the laboratory. The preliminary stage for raising wild fish is transporting from nature to the aquacul-ture environment. Generally, to minimize fish stress during transport in a closed system, anesthetics are added to the transport media. Furthermore, good adaptation in the aquaculture environment will lead to the process of reproduction as the ultimate goal of domestication of wild fish. The research objective is to analyze the transportation of closed systems and the rearing of O. javanicus post-transportation from Tunda Island. Research observations were carried out on behavior, survival, the number of eggs, and male: female sex ratio. Transport using an additional anesthetic treatment of 0.4 mL L-1 and without anesthesia, with fish density of 16 L-1. Anesthesia used is the commercial product Ocean Free® Special Arowana Stabilizer. Transportation is carried out for 11 hours. After that, rearing post-transportation is carried out for 16 days. The results showed that the transportation of O. javanicus can use a closed system without the addition of anesthesia with a density of 16 L-1 for 11 hours. In post-transport maintenance, fish begin active swimming on day 5, swim in groups continuously on day 6, start responding to natural food on day 3 and artificial feed on day 7, and produce a final survival of 91.67%. During maintenance, O. javanicus produces 104 eggs, 0.94 ± 0.06 mm in diameter and has an attaching filaments and a non-attaching filaments in the chorion. Oryzias javanicus is an egg depositor that can spawn with a 1: 1 and 1: 2 sex ratio.