&lt;b&gt;Association between periphyton and bioflocs systems in intensive culture of juvenile Nile tilapia

Davi De Holanda Cavalcante,Marcelo Vinícius Do Carmo E Sá,Francisco Roberto Dos Santos Lima,Vanessa Tomaz Rebouças

doi:10.4025/actascianimsci.v38i2.27592

<b>Association between periphyton and bioflocs systems in intensive culture of juvenile Nile tilapia

Davi De Holanda Cavalcante, Marcelo Vinícius Do Carmo E Sá + Show 2 more

Open Access

https://doi.org/10.4025/actascianimsci.v38i2.27592

Copy DOI

Abstract

The present work aimed at determining the effects of the association between the periphyton-based system with the bioflocs-based system in the intensive culture of juvenile Nile tilapia (1.56 ± 0.07 g; 72 fish m-3), on variables of water quality, growth performance and effluent quality after 10 weeks. The experiment was arranged in a 2 x 2 factorial randomized block design with four treatments and five repetitions each. The factors tested were the following: ‘underwater structure’ (absence and presence) and ‘adjustment of the C: N ratio of water’ (no and yes). The final fish body weight, specific growth rate and yield were higher (p < 0.05) in the C: N-adjusted tanks. The presence of submerged structures in the tanks had no significant influence on those same variables. It was concluded that the periphyton-based system is not indicated for intensive farming of Nile tilapia, in which there is a high allowance of artificial feed to fish.

Highlights

Intensive systems of fish farming are based on the supply of large amounts of artificial food to the farmed animals
The electrical conductivity (EC) of the water was significantly affected by the adjustment of the C: N ratio of water, in which the C: N-adjusted tanks presented the higher values of EC (Table 1)
The presence of the underwater structures has not affected the concentrations of free CO2 in water (Table 2)

Summary

Introduction

Intensive systems of fish farming are based on the supply of large amounts of artificial food (balanced rations) to the farmed animals Those systems have high costs and may cause environmental problems, since most of the feed given to the animals is not consumed and accumulate in the environment as fish feces (Avnimelech, 1999). Such organic debris, which are rich in nitrogen and phosphorus, can cause eutrophication of the natural ecosystems when they are directly discharged into the receiving water bodies (Green, Schrader & Perschbacher, 2014). Among the solutions currently proposed, it is highlighted the use of artificial substrates and the bioflocs technology (BFT)

Objectives

Methods

Results

Conclusion