Growth monitoring of koi fish (Cypri nus carpio) in natural hatchery techniques in Umbulan, Pasuruan, East Java

Koi fish (Cyprinus carpio) are one of the most popular ornamental fish commodities in the world. The purpose of this study was to analyze the growth and monitoring of koi fish on natural hatchery techniques. This research was conducted at the Technical Implementation Unit of Freshwater Aquaculture Development in Umbulan, Pasuruan, East Java Province between December 2017 and January 2018. The koi fish breeding technique in Umbulan is done naturally using two females with the same weight of 1.5 kg and three males with a weight of 1.8 kg, 1.5 kg and 1.5 kg respectively. The maintenance of the larvae included feeding, the monitoring of the larvae and the associated water quality measurements. The hatching rate of the koi fish eggs was 80%. The specific growth rate during maintenance was 0.164%, and the growth rate for every week was 1.822 x 10^-3 g/day; 1.34 x 10^-3 g/day; and 1.75 x 10^-3g/day. The feed conversion ratio was 1.38 and the survival rate was 73.8%. The average of the water quality values including temperature was 26.25° C. The pH was 7.53, the dissolved oxygen was 6.26 mg / L, NO₃ was 0.75 mg / L, NO₂ was 0.01 mg / L, Fe was 0.06 mg / L and PO₄ was 0.74 mg / L.