The Impact of Stocking Density on Water Quality, Survival and Growth Performance of Free‐Swimming Larvae of Goldfish, <i>Carassius auratus</i> (Linnaeus, 1758) in an Indoor Biofloc System

A 30‐day experiment was conducted to assess the influence of varying stocking densities (2, 4, 6 and 8 larvae L −1 ) on the growth performance and survival of free‐swimming larvae of Carassius auratus , commonly known as goldfish, within an indoor biofloc system. The larvae (7.05 ± 0.02 mm in length and 1.40 ± 0.00 mg in weight) were stocked in circular tanks wherein a volume of 50 L of water was maintained and provided with vigorous aeration. The experiment used a completely randomised design with five replicates for each density group. A diet comprising a 1:1 mixture of powdered groundnut oil cake and rice bran (RB) was provided as feed. The RB was added daily as a carbon source to maintain the C/N ratio at 20:1. The highest % length gain (209.46 ± 1.47), % weight gain (14028 ± 99.65), specific growth rate (SGR) (16.50 ± 0.02), survival (85.00% ± 1.00) and the lowest apparent feed conversion ratio (AFCR) (1.84 ± 0.01) were recorded in the density group of 2 larvae L −1 ( p &lt; 0.05) as compared to other density groups. The results indicated a better stocking density of 2 larvae L −1 for growing free‐swimming larvae of goldfish for 30 days.