Diatomaceous earth application to improve shrimp aquaculture: growth performance and proximate composition of Penaeus vannamei juveniles reared in biofloc at two salinities

Abstract

Silicon dioxide has been used in aquaculture to increase the abundance of diatoms; however, its relationship with water quality or productive performance has not been investigated. Our study evaluated the effect of diatomite on water quality, growth performance and proximate composition of Penaeus vannamei reared in seawater (E1) and brackish water (E2) with biofloc. Two independent experiments (E1 and E2), each one with three treatments with biofloc were evaluated: treatments D with a weekly addition of diatomite (10 g m-3); the treatments D plus a continuous inoculum of diatom Chaetoceros muelleri (DD); and only biofloc like control, for E1 was used post-larvae with an initial body weight (IBW) of 0.0075 g; while in E2 was used juvenile with an IBW of 1.42 g. After seven weeks in E1, non-significant differences were registered in survival, weight gain (WG), specific growth rate (SGR) and feeding conversion rate (FCR) between DD treatment and control. However, in E2, the treatment D showed significantly higher WG (9.83 g) and SGR (4.25% d-1) compared to control (7.64 g and 3.86% d-1, respectively). Conversely, the FCR was lower in treatment D (1.16) compared to control (1.49). Non-significant differences were recorded in the proximate composition for shrimp, periphyton, and biofloc, among treatments in both experiments. Levels of nitrogenous wastes were similar among treatments. While in E2, the concentration of settleable solids was significantly higher in treatments with diatomite compared to control. Our results recommend the use of diatomite to improve the growth performance of shrimps cultured in brackish water with biofloc.

Preparation of Copper Nanoparticles/Diatomite Nanocomposite for Improvement in Water Quality of Fishponds

“…It has been used for the treatment of shrimp and fshponds, opening a new direction for the management of water quality in aquaculture. Tis discovery leads to benefts for the environment and economic values [6]. If DA has been modifed by the deposition of an antibacterial agent such as copper nanoparticles on it, the usable value will increase manyfold.…”

“…Diatomite (DA) is an inorganic clay mineral that does not contain harmful components; the adsorption of pollutants is fast and easy to control, so it shows superiority compared to other methods to improve water quality in aquaculture [6]. Although traditional sorbents can eliminate impurities from water, some properties, like the limitation of antibacterial activity or the sorption capacity, can decrease their efciency in application.…”