Rodrigo Schveitzer

• PhD
• Professor at Federal University of São Paulo

The study assessed a method for synchronizing molting in Pacific white shrimp (Litopenaeus vannamei) postlarvae (PLs) by lowering salinity to prevent molting during the transportation and storage of PLs. For this purpose, 96,000 L. vannamei (PL15 average length of 9.1 ± 1.2 mm) were randomly distributed into eight experimental units (12,000 per uni...

Microbial flocs (bioflocs) present in the water of intensive culture tanks are formed by a variety of microorganisms and other kinds of particulate organic matter, such as faeces and uneaten feed. During shrimp culture, biofloc concentrations increase. It has been reported that some level of control over biofloc levels, which can be quantified by t...

This study investigated if the intensity of sedimentation through settling tanks modifies the bacterial community composition of biofloc systems and affects performance of shrimp. A 50-day trial, which was conducted with Pacific White Shrimp juveniles (2.6 g ± 0.0 g) stocked at a density of 906 shrimp m−3, evaluated two different biofloc concentrat...

In no water exchange aquaculture operations, sedimentation has been employed to control the level of microbial flocs to decrease oxygen consumption and to prevent clogging of gills in cultured organisms. Nevertheless, the impact of this practice on the culture microbial community was not documented. The current study evaluated the impact of adding...

Effect of K⁺ and Mg²⁺ in water on the performance of Litopenaeus vannamei using bioflocs was evaluated. Control had water with K:Mg (1:4.57) and other treatments (K:Mg of 1:5.4, 1:4.65, and 1:3.77), both with salinity of 4 g/L. Initial mean weight of shrimp was 0.08 ± 0.007 g. No difference in shrimp growth performance and survival was observed (P...

We investigated whether the positive impacts of artificial substrates on shrimp performance are altered in any way by their format or mode of fixation in the tanks. To examine this question, substrates were fixed vertically in the water column in three different configurations: SCF treatment (Substrate Completely Fixed), SPF treatment (Substrate Pa...

A 13-day nursery trial was conducted to evaluate the performance of young Litopenaeus vannamei post-larvae (from PL6 to PL18) reared in both biofloc and microalgae-based systems at a stocking density of 67 PLs L⁻¹. The effects of different concentrations of total suspended solids (TSS) on PL performance were also evaluated. One experimental group w...

The aim of this study was to evaluate the effect of two methodologies of carbohydrate fertilization on the volume and characteristics of effluent from intensive biofloc shrimp cultivation. Six fiberglass circular tanks (50 m² each) were divided into two treatments. In the treatment called continuous (CONT), the tanks received daily molasses fertili...

This study aimed to evaluate the effect of different carbon sources, at two fertilization doses, on water quality and shrimp performance in a biofloc system. To accomplish this, marine shrimp Litopenaeus vannamei post-larvae (PL17) were cultured in intensive (150 animals m−2) zero water-exchange biofloc technology (BFT). The experiment was conducte...

Biofloc systems rely on microbial processes in the water column to recycle animal waste products, reducing the need for water exchange. These increases biofloc concentration in the water and some form of removal is needed. An experiment was carried out to evaluate two management practices to control biofloc in Litopenaeus vannamei culture. Six tank...

We assessed the hatchery performance of Litopenaeus vannamei between the mysis1 and postlarva5 stages, in a zero-exchange biofloc system. Two sources of organic carbon (molasses and dextrose) were evaluated and water quality, zootechnical parameters, microbiology, and water consumption during production were compared between carbon-supplemented and...

A 21-day experiment was conducted to evaluate the application of biofloc technology in South American catfish larvae (Rhamdia quelen) grown at a density of 25 larvae L− 1. The effect of different concentrations of biofloc on the performance of larvae was also analyzed. Five treatments were tested; in three of them, catfish larvae were grown in enri...

Although the use of artificial substrates can favor shrimp culture, some studies indicate that their presence in growth tanks does not improve water quality or the performance of the animals. One objective of this study was to evaluate whether the presence of artificial substrates modifies the microbial activity and the water quality of the culture...

Most research on biofloc systems has been performed in greenhouses with abundant natural light. The functionality of these systems in an environment devoid of light remains poorly understood, especially with regard to growth and survival of reared animals. This study evaluated the performance of Litopenaeus vannamei reared in a biofloc system with...

Resumo – O objetivo deste trabalho foi avaliar a substituição de dois níveis de inclusão de farinha de peixe por outros ingredientes, nas dietas de Litopenaeus vannamei cultivados em sistema bioflocos. Foram avaliadas dietas sem uso de farinha de peixe (dieta A, 100% de substituição), com inclusão de 12,5% de farinha de peixe (dieta B, 40% de subst...

The objective of this work was to evaluate the substitution of two fish meal inclusion levels by other ingredients, in the diets of Litopenaeus vannamei reared in a biofloc system. The following diets were evaluated: without fish meal (diet A, 100% replacent), with addition of 12.5% of fish meal (diet B, 40% replacent), and a control diet with addi...

Bacterial diseases, mainly those caused by bacteria of the Vibrio genus, are responsible for significant economic losses in the shrimp production. This study aimed to verify the concentration of calcium hydroxide [Ca(OH)(2)] able to inhibit growth of Vibrio harveyi in vitro, and also to test in vivo its use in culture ponds. For the in vitro experi...

From January to December 1995, 332 individuals of the Callinectes ornatus species were collected from the Itapocoroy inlet in Penha, Sta. Catarina, Brazil to study its natural diet and the seasonal variations of diet. Results showed a diversified trophic spectrum with a generalized dietary strategy comprising the algae, macrophyta, foraminiferida,...

In the period of January and December, 1995, there were collected by means of overtrawl, 12977 samples of macroinvertebrates and demersal fishes, in the Armação do Itapocoroy, Penha (SC), between the depths of 6 to 10 meters, in the periods of morning, afternoon, and evening. There were registered the incidence of 57 families, 80 kinds and 92 speci...