Effects of Microalgae on Growth and Nutritional Performance of Koi Carp, Cyprinus Carpio, (Linnaeus, 1758), and Leafy Vegetables Raised in Aquaponic System

Abstract

This study was carried out to assess the dietary effects of freshwater microalga, Spirulina platensis on the growth performance and nutrient utilisation in Koi carp, Cyprinus carpio fingerlings raised in aquaponic system with fluted pumpkins. Five feeds were formulated with different inclusion levels of spirulina at 0%, 20%, 30%, 40% and 50% each in diet 1, 2, 3, 4 and 5 denoted as T1(Control), T2, T3, T4 and T5 respectively to replace soybean meal respectively. One hundred and fifty Koi carp, C. carpio fingerlings (2.35g±0.05) were stocked in the aquaponics system and fed with commercial fish feed for 56days.The experiment were replicated with three tanks per replicate. Fish biological performance during the experiment was measured based on growth performance and nutrient utilization. The growth of the leafy vegetable was measured, and inferential statistics were done using one way analysis of variance (ANOVA) to compare the growth performance and nutrient utilization of fish at 95% level of confidence and 0.05 level of significance. The study found that the water quality, as well as the fish performance in the system were all within the recommended limits and appreciable performance respectively. ANOVA result showed a statistically significant difference among the inclusion levels of the microalgae. The result showed that were significant differences (P<0.05) in the growth and nutrient utilization parameters with treatment 4 with 75% spirulina inclusion having the best protein efficiency ratio, feed conversion and feed efficiency ratios. The study concluded that microalgae and Fluted pumpkins have better production performance and growth performance in aquaponic system thus, integration of Fluted Pumpkin and C. carpio in aquaponics system has the potential of adding more to the benefits of the system in terms of productivity.