Reproductive performance of crossbreeding between local female and imported male koi at CV. Indokoi Malang

The high demand for koi fish must be supported by an adequate
supply of fry, both in quantity and quality. High-quality fry comes from
superior broodstock. This study aimed to evaluate the quantity, type, and
quality of fry produced by crossbreeding local and imported broodstock. A
descriptive quantitative method was used, with natural spawning at a ratio
of 1:3 (female), involving Shiro F1, local Shiro, local Showa, and imported
Ginrin Shiro. Results showed a fecundity of 103,800 eggs, with fertilization,
hatching, and survival rates of 84%, 93%, and 74.7%, respectively. The first
selection yielded 79% high-quality fry, while the second selection produced
10% high-quality fry. Showa fry dominated the second selection, comprising
84% of that batch and 9.2% of the total fry, while Shiro fry made up 16% of
the second selection and 1.7% of the overall fry. The highest daily growth
rate occurred in the first week (4.6%/day), while the lowest was in the
second week (2.08%/day). The highest specific growth rate was also in the
first week (36.43%/day), with the lowest in the fourth week (5.61%/day).
Water quality remained suitable for koi fry survival throughout the study.