Reproduction aspect of green swordtail, Xiphophorus hellerii Heckel 1848 in Tamblingan Lake, Bali

Abstract
Eco-biological information of green swordtail in Tamblingan Lake is unknown. This research aimed to reveal sex ratio, gonadosomatic index, viviparity, spawning time and location of green swordtail in Tamblingan Lake. Fish was collected by gill nets with a mesh size of 0.5 and 1.0 cm in five sampling stations from January to June 2019. Total length and body weight of all fish samples were measured then dissected to observe the level of gonad maturity and viviparity in female fish. A total of 373 green swordtail with total length ranged and body weight ranged from 30.4-69.2 mm and 0.7935 – 7.6612 g, respectively. The results showed that males outnumberd of females in all sampling periods. Gonadosomatic index of male and female ranged from 0.159-1.239 and 0.204-13.592, respectively. The mature individuals were captured in all sampling stations and observation times. This species has a good reproductive potential with viviparity ranges between 6-54 juveniles.