EFFECTS OF SUBSTRATE VARIATION ON THE REPRODUCTIVE EFFECTIVENESS OF Corydoras julii

Abstract

Corydoras julii is a freshwater ornamental fish species highly favored by both local and international markets. However, breeders often face challenges in achieving optimal egg production, which is suspected to be influenced by the type of spawning substrate used. This study aimed to determine the most effective substrate for improving the spawning performance of C. julii. The experiment was conducted using a Completely Randomized Design (CRD) with four treatments and three replications, consisting of no substrate (control, K), raffia string (T), PVC pipe (P), and Hydrilla verticillata (H). Parameters observed included egg productivity, fertilization rate, hatching rate, and larval survival rate. The results showed that the highest egg productivity was obtained in the PVC pipe treatment, with an average of 2081 ± 125.83 eggs. However, differences in substrate type did not significantly affect the fertilization rate, hatching rate, or survival rate. Water quality parameters, including temperature, pH, and dissolved oxygen, remained within the optimal range for spawning throughout the study. In conclusion, the PVC pipe was identified as the most effective substrate for enhancing egg productivity in Corydoras julii breeding without negatively affecting other reproductive parameters.