Rhodococcus sp. as probiotic bacteria for increase the survival, growth and coloration of fish Puntius conchonius

Abstract

An The aim of this study was to evaluate the effect of bacteria Rhodococcus sp. in growth, survival, and coloration of Puntius conchonius. It was obtained a batch of 300 larvae of seven days after hatching and were divided in six aquariums of 60 litters (50 org per aquarium) and fed with Artemia franciscana nauplii, enriched with Rhodococcus sp. at a concentration of 1 x 10 7 cells per milliliter. There was also a control treatment where larvae were only fed with Artemia nauplii without probiotic. Every fifteen days, biometric parameters were obtained such as weight, total length, high, wide. Also, physicochemical parameters were measured like pH, dissolved oxygen, nitrates, nitrites, and ammonium, and it was evaluated the increase in fish coloration following the method for pigment extraction. Feeding period was carried out for 60 days. Survival was 100% in both treatments, but in fish fed with Rhodococcus sp. presented better growth results in total length, wide and weight, than control group. Regarding to fish coloration, variance analysis showed significant differences between treatments (P=0.035), having a better coloration in tissue of fish fed with probiotic, proving that this genus present enormous benefits as it not only improves productive parameters, but also increases coloration of fish; fundamental aspect for ornamental species commercialization.