Cage culture of Nile tilapia (Tilapia nilotica) without supplemental feeding in an organically enriched pond at three stocking density levels

• Main Author: Borbon, Veronica Xavier L.
• Format: text
• Language: English
• Published: Animo Repository 1983
• Subjects: Nile tilapia; Fish culture; Aquaculture and Fisheries
• Online Access: https://animorepository.dlsu.edu.ph/etd_masteral/1002
• Institution: De La Salle University

The effect of stocking density on the production of mixed-sex 120d cage-cultured Tilapia nilotica in a sewage-contaminated and manure-loaded pond without supplemental feeding was investigated. Fingerlings were randomly stocked in 1m3 floating cages at stocking density treatments of 50, 100 and 200 fish/cage, and each treatment replicated thrice. Fish initially stocked at the lowest density level showed the highest individual mean weight increment and growth rate but produced the lowest yield at the end of the 120d test period. Contrastingly, although fingerlings initially caged at the highest stocking density attained the lowest mean gain in weight and growth rate, it yielded the highest biomass at harvest. The functional relation of fish yield (Y) with stocking density was found to be significant (p 0.01), mathematically expressed by the equations Y. Since the experimental fish received no supplemental feeding, its dependence on the natural productivity of the organically-enriched trial pond was assessed. The functional contribution of gross primary production on net fish yield was found significant (p 0.05) only at the lowest stocking density levels. Algal density showed insignificant (p 0.05) correlation with fish yields at all stocking density levels. Inspite of the occasionally stressful limnological condition of the culture medium, physico-chemical parameters monitored were found within the tolerance range of Tilapia nilotica. In all the experimental cages, survival rate was 100 percent.