Effect of two diets on the fecundity of ablated and non-ablated female of Macrobrachium amazonicum

Macrobrachium amazonicum is a species of freshwater shrimp of great importance for aquaculture and to know its reproductive potential, through the study of its fertility is necessary. Therefore, this study aimed to evaluate the effect of two different diets on the reproductive performance of the species, whether or not adopting the ablation procedure. The experiment was carried out in a completely randomized design in a 2 x 2 factorial arrangement, with two types of feed (inert and fresh) and two conditions (ablated and non-ablated females), using six replicates per treatment. After 10 days of spawning, the eggs were removed and counted in their entirety. For each female, three spawns were obtained, totaling 72 samples. The fertility rate, the interval between spawning and the weight gain of the females were analyzed. There was no interaction between the studied factors, except for weight gain, in which ablated females that received fresh feed gained up to three times more weight than non-ablated females. Females that received fresh feed obtained higher fertility (1,373.9 eggs) than those that received only inert feed (1,084.1 eggs). The interval between spawns was 1.6 days shorter in ablated females.(AU)

Water parameters correlated with the zootechnical performance of shrimp Litopenaeus vannamei grown in oligohaline waters

The present study aimed to correlate the influence of water quality, cultivation time, area, and density of ponds on the zootechnical performance of shrimp Litopenaeus vannameiin oligohaline waters. It was demonstrated that, under the conditions of this research, better control of temperature, pH and water alkalinity can be employed. Ammonia levels were within the normal range and correlated positively with the growth rate (ρ= 0.69859) and production (ρ= 0.66362) of the ponds. There was also a positive correlation between cultivation time and pond density with shrimp weight (ρ= 0.75305 and 0.68933) and pond productivity (ρ= 0.74763 and 0.79367, respectively). Negative correlations were observed between: I) pH with shrimp survival (ρ= -0.73238) and pondproduction (ρ= -0.68696); II) alkalinity and pond production (ρ= -0.66162). The results show that the cultivation of shrimp L.vannameiin oligohaline waters is viable and there is potential for increased productivity associated with better hydrologicalmonitoring and use of higher density and cultivation time by some producers.(AU)

Impact of production chain on defects of farmed shrimp (Penaeus vannamei) / Impacto da cadeia produtiva sobre os defeitos do camarão de cultivo (Penaeus vannamei)

The production chain of Penaeus vannamei require detailed quality evaluation from farm to processing plant, to maintain the quality standards. We evaluated the impact of production chain steps in main defects of P. vannamei as red hepatopancreas, detached cephalothorax and post-mult. Red hepatopancreas and detached cephalothorax exhibited the highest defect incidence, which are related to capture method and post-harvest handling procedures. Red hepatopancreas showed a positive correlation (r = 0.56; P = 0.008) with post-molts. The Principal Component Analysis (PCA) explained 53.91% of total data variance, where the second principal component (PC2) contributed with 19.39% separating shrimp defects and management steps based on square cosines of red hepatopancreas and transport time. These results suggested that steps of production chain as well as post mortem process are directly related to shrimp defects, and the knowledge of these factors can contribute to improve the product quality.

A cadeia produtiva do Penaeus vannamei exige avaliações detalhadas quanto à qualidade do produto desde o campo até a planta de processamento, considerando a importância da manutenção dos padrões de qualidade. Foi avaliado o impacto das etapas da cadeia produtiva nos principais defeitos do P. vannamei como hepatopâncreas vermelho, cefalotórax desprendido e pós-mudas. Hepatopâncreas e o cefalotórax desprendido foram os defeitos de maior incidência, e estão relacionados ao método de despesca e manuseio pós-abate. O hepatopâncreas vermelho apresentou correlação positiva (r = 0,56; P = 0.008) com pós-muda. A Análise de Componentes Principais (ACP) explicou 53,91% da variância total dos dados, onde o segundo componente principal (PC2) contribuiu com 19,39% separando os defeitos do camarão e as etapas de manejo com base nos cossenos quadrados do hepatopâncreas vermelho e tempo de transporte. Esses resultados sugerem que as etapas da cadeia produtiva bem como o processo post mortem estão diretamente relacionados aos defeitos dos camarões, e o conhecimento desses fatores pode contribuir para a melhoria da qualidade do produto.

Apparent digestibility of protein and essential aminoacids from commonly used feed ingredients in Brazil for juvenile shrimp Litopenaeus vannamei

- This study determined the apparent digestibility for crude protein (ACPD) and essential aminoacids (AEAAD) of ingredients for Litopenaeus vannamei fed diets containing soy protein concentrate (SPC), corn gluten meal (CGM), poultry byproduct meal (PBM), meat and bone meal (MBM), hydrolyzed feather meal (HFM), spray-dried blood meal (DBM), tilapia byproduct meal (TBM), Brazilian marine fish meal (BFM), salmon byproduct meal (SLM), and krill meal (KRM). Digestibility was estimated using chromic oxide as a marker in a reference (REF) mixture. Shrimp of 6-8 g body weight were reared over three separate experimental stages lasting 29-30 days each. Shrimp survival exceeded 96% and was unaffected by test ingredient. The ACPD ranged from 66.7% for a diet containing DBM to 84.2% for the REF diet. Higher ACPD were observed for aquatic compared with plant and terrestrial animal byproducts. Aside from SPC (79.3%), ACPD for CGM was low at 47.5%. Among terrestrial animal byproducts, ACPD was higher for MBM compared with PBM, DBM, and HFM (71.2, 62.8, 48.6, and 45.9%, respectively). With the exception of BFM (59.7%), ACPD for all other aquatic proteins was high (KRM, 84.3%; TBM, 83.3%; SLM, 78.9%). Aquatic proteins have higher crude protein (CP) and essential aminoacid (EAA) digestibility for shrimp. Ingredients SLM, SPC, TBM, and KRM are preferable in feeds for the whiteleg shrimp since they carry a high CP and EAA content (>600 g kg−1) combined with ADC near or in excess of 80%.(AU)

Hygienic and sanitary characteristics of dry salted fish marketed in Porto Velho city, Rondônia ­ Brazil / Características higiênico-sanitárias de pescado salgado seco comercializado em Porto Velho, Rondônia ­ Brasil

Handcrafted salted fish is marketed weekly in retail markets and public fairs in the Porto Velho city, Rondônia sate, Brazil. Knowing the microbiological quality of these products is essential for public health, given that such products are not subject to any quality control. The aimed of the study was to evaluate the hygienic-sanitary characteristics and the moisture content of pirarucu and salted and dried shrimp marketed in the Porto Velho city. Twenty samples were collected, 10 pirarucu and 10 shrimp, in February and June 2019. For microbiological analysis, surface plating was performed using acidified potato agar, for molds and yeasts, and PCA agar for halophilic bacterias. Moisture was determined by gravimetry, using an oven at 105° C. Results for molds and yeasts on pirarucu ranged <10 log CFU/g (absent) to 3 log CFU/g. For shrimp, values ranged <10 log CFU/g to 3.57 log CFU/g. For halophilic bacterias, contents ranged <10 log CFU/g to 6.30 log CFU/g in pirarucu samples and <10 log CFU/g to 6.97 log CFU/g in shrimp samples. The variation in moisture content ranged 36.99 to 54.31% for pirarucu, and 40.6 to 56.82% for shrimp. The results obtained may be related to poor hygienic conditions in processing, the lack of hygiene of utensils and places for handling, or even the quality of the raw material used.(AU)

Pescado salgado preparado artesanalmente é semanalmente comercializado em mercados varejistas e feiras públicas na cidade de Porto Velho, Rondônia. Conhecer a qualidade microbiológica desses produtos é essencial para a saúde pública, haja visto, que tais produtos não estão sujeitos a nenhum controle de qualidade. O objetivo do estudo foi avaliar as caracterís-ticas higiênico-sanitárias e o teor de umidade de pirarucus e camarões salgados e secos comercializados em Porto Velho. Foram coletadas 20 amostras, 10 de pirarucu e 10 de camarão, em fevereiro e junho de 2019. Para as análises microbiológicas foi realizado o plaqueamento em superfície usando-se ágar batata acidificado, para bolores e leveduras, e ágar PCA para as bacté-rias halofílicas. A umidade foi determinada por gravimetria, com uso de estufa a 105°C. Os resultados para bolores e leveduras em pirarucu variaram de <10 log UFC/g (ausente) a 3 log UFC/g. Para os camarões os valores variaram de <10 log UFC/g a 3,57 log UFC/g. Para as bactérias halofílicas os teores variaram de <10 log UFC/g a 6,30 log UFC/g nas amostras de pirarucu e de <10 log UFC/g a 6,97 log UFC/g nas amostras de camarão. A variação nos teores de umidade foi de 36,99 a 54,31% para o pirarucu, e de 40,6 a 56,82% para o camarão. Os resultados obtidos podem estar relacionados às más condições higiênicas no processamento, à falta de higiene dos utensílios e dos locais de manipulação, ou ainda, à qualidade da matéria-prima empregada.(AU)

The effect of deproteinization methods on the properties of glucosamine hydrochloride from shells of white leg shrimp (Litopenaeus vannamei) and black tiger shrimp (Penaeus monodon) / Efeito de métodos de desproteinização nas propriedades do cloridrato de glucosamina de cascas de camarão de pernas brancas (Litopenaeus vannamei) e cascas de camarão de tigre preto (Penaeus monodon)

The effect of methods to remove protein content on the properties of glucosamine hydrochloride from the shells of white leg shrimp (Litopenaeus vannamei) and black tiger shrimp (Penaeus monodon) was investigated. Chitin from shrimp shells was obtained by demineralization in 6% HCl for 12h, deproteinization by two different methods (first group soaked in 8% NaOH for 36h and second group treated in Alcalase enzyme at the concentration of 0.2% for 36h). Two group samples were converted to glucosamine hydrochloride by soaking in 36.76% HCl solution for 5h at 85 °C. The results of fourier transform infrared spectroscopy (FTIR), solubility and recovery yield analysis showed that deproteinization methods did not significantly affect the properties of glucosamine hydrochloride. However, glucosamine hydrochloride from white leg shrimp shells contained higher recovery yield and solubility than black tiger shrimp shells.

Investigou-se o efeito de métodos para remover o conteúdo de proteínas nas propriedades do cloridrato de glucosamina das conchas de camarão de pernas brancas (Litopenaeus vannamei) e camarão de tigre preto (Penaeus monodon). A quitina das cascas de camarão foi obtida por desmineralização em HCl a 6% por 12 h, desproteinização por dois métodos diferentes (primeiro grupo embebido em NaOH a 8% por 36 h e segundo grupo tratado na enzima Alcalase na concentração de 0,2% por 36 h). Duas amostras de grupo foram convertidas em cloridrato de glucosamina por imersão em solução de 12M HCl por 5 h a 85 °C. Os resultados das análises de FTIR, solubilidade e rendimento de recuperação mostraram que os métodos de desproteinização não afetaram significativamente as propriedades do cloridrato de glucosamina. No entanto, o cloridrato de glucosamina de cascas de camarão de pernas brancas continha maior rendimento e solubilidade de recuperação do que as cascas de camarão tigre preto.

The effect of deproteinization methods on the properties of glucosamine hydrochloride from shells of white leg shrimp (Litopenaeus vannamei) and black tiger shrimp (Penaeus monodon) / Efeito de métodos de desproteinização nas propriedades do cloridrato de glucosamina de cascas de camarão de pernas brancas (Litopenaeus vannamei) e cascas de camarão de tigre preto (Penaeus monodon)

ABSTRACT: The effect of methods to remove protein content on the properties of glucosamine hydrochloride from the shells of white leg shrimp (Litopenaeus vannamei) and black tiger shrimp (Penaeus monodon) was investigated. Chitin from shrimp shells was obtained by demineralization in 6% HCl for 12h, deproteinization by two different methods (first group soaked in 8% NaOH for 36h and second group treated in Alcalase enzyme at the concentration of 0.2% for 36h). Two group samples were converted to glucosamine hydrochloride by soaking in 36.76% HCl solution for 5h at 85 °C. The results of fourier transform infrared spectroscopy (FTIR), solubility and recovery yield analysis showed that deproteinization methods did not significantly affect the properties of glucosamine hydrochloride. However, glucosamine hydrochloride from white leg shrimp shells contained higher recovery yield and solubility than black tiger shrimp shells.

RESUMO: Investigou-se o efeito de métodos para remover o conteúdo de proteínas nas propriedades do cloridrato de glucosamina das conchas de camarão de pernas brancas (Litopenaeus vannamei) e camarão de tigre preto (Penaeus monodon). A quitina das cascas de camarão foi obtida por desmineralização em HCl a 6% por 12 h, desproteinização por dois métodos diferentes (primeiro grupo embebido em NaOH a 8% por 36 h e segundo grupo tratado na enzima Alcalase na concentração de 0,2% por 36 h). Duas amostras de grupo foram convertidas em cloridrato de glucosamina por imersão em solução de 12M HCl por 5 h a 85 °C. Os resultados das análises de FTIR, solubilidade e rendimento de recuperação mostraram que os métodos de desproteinização não afetaram significativamente as propriedades do cloridrato de glucosamina. No entanto, o cloridrato de glucosamina de cascas de camarão de pernas brancas continha maior rendimento e solubilidade de recuperação do que as cascas de camarão tigre preto.

The fishery of pelagic shrimp aviú Acetes paraguayensisin eastern Brazilian Amazon / A pesca do camarão pelágico aviú Acetes paraguayensisna Amazônia oriental brasileira

The pelagic shrimp, Acetes paraguayensis Hansen, 1919, is an ecologically important species with an enormous socioeconomic value for the human populations in the regions where it occurs. This species also has considerable potential for shrimp farming, although few details are known of its biology. This study investigated the artisanal exploitation of A. paraguayensis stocks in the northern Brazilian municipality of Santarém over 16 months, focusing on the types of equipment most used to harvest of this shrimp, the fishing dynamics, and production patterns. The matapi trap was the principal method used of harvesting A. paraguayensis in the study region, conforming to a typically artisanal, small-scale fishing production system. This study results provide an essential research tool for developing conservation and management strategies and the eventual establishment of farming protocols.

O camarão pelágico, Acetes paraguayensis Hansen, 1919, é uma espécie ecologicamente importante, de enorme valor socioeconômico para as populações humanas localizadas nas regiões produtoras. Essa espécie tem também um potencial considerável para o cultivo, embora poucas informações sejam conhecidas da sua biologia. Assim o presente estudo investigou a exploração artesanal das po-pulações de A. paraguayensis no município paraense de Santarém, no Norte do Brasil, por 16 meses, concentrando-se nos tipos de equipamento mais utilizados para sua captura, na dinâmica pesqueira e nos padrões de produção. O matapi foi o principal método utilizado, configurando-se como um sistema de produção pesqueira tipicamente artesanal de pequena escala. Os resultados do presente estudo constituem importante instrumento de investigação para o desenvolvimento de estratégias de conservação e gestão e o eventual estabelecimento de protocolos de cultivo.

The effect of deproteinization methods on the properties of glucosamine hydrochloride from shells of white leg shrimp (Litopenaeus vannamei) and black tiger shrimp (Penaeus monodon) / Efeito de métodos de desproteinização nas propriedades do cloridrato de glucosamina de cascas de camarão de pernas brancas (Litopenaeus vannamei) e cascas de camarão de tigre preto (Penaeus monodon)

The effect of methods to remove protein content on the properties of glucosamine hydrochloride from the shells of white leg shrimp (Litopenaeus vannamei) and black tiger shrimp (Penaeus monodon) was investigated. Chitin from shrimp shells was obtained by demineralization in 6% HCl for 12h, deproteinization by two different methods (first group soaked in 8% NaOH for 36h and second group treated in Alcalase enzyme at the concentration of 0.2% for 36h). Two group samples were converted to glucosamine hydrochloride by soaking in 36.76% HCl solution for 5h at 85 °C. The results of fourier transform infrared spectroscopy (FTIR), solubility and recovery yield analysis showed that deproteinization methods did not significantly affect the properties of glucosamine hydrochloride. However, glucosamine hydrochloride from white leg shrimp shells contained higher recovery yield and solubility than black tiger shrimp shells.(AU)

Investigou-se o efeito de métodos para remover o conteúdo de proteínas nas propriedades do cloridrato de glucosamina das conchas de camarão de pernas brancas (Litopenaeus vannamei) e camarão de tigre preto (Penaeus monodon). A quitina das cascas de camarão foi obtida por desmineralização em HCl a 6% por 12 h, desproteinização por dois métodos diferentes (primeiro grupo embebido em NaOH a 8% por 36 h e segundo grupo tratado na enzima Alcalase na concentração de 0,2% por 36 h). Duas amostras de grupo foram convertidas em cloridrato de glucosamina por imersão em solução de 12M HCl por 5 h a 85 °C. Os resultados das análises de FTIR, solubilidade e rendimento de recuperação mostraram que os métodos de desproteinização não afetaram significativamente as propriedades do cloridrato de glucosamina. No entanto, o cloridrato de glucosamina de cascas de camarão de pernas brancas continha maior rendimento e solubilidade de recuperação do que as cascas de camarão tigre preto.(AU)

Effect of dietary protein and genetic line of Litopenaeus vannamei on its hepatopancreatic microbiota

Host genetics and diet can exert an influence on microbiota and, therefore, on feeding efficiency. This study evaluated the effect of genetic line (fast-growth and high-resistance) in Pacific white shrimp (Litopenaeus vannamei) on the hepatopancreatic microbiota and its association with the feeding efficiency in shrimp fed with diets containing different protein sources. Shrimp (2.08 ± 0.06 g) from each genetic line were fed for 36 days with two dietary treatments (animal and vegetable protein). Each of the four groups was sampled, and the hepatopancreatic metagenome was amplified using specific primers for the variable V4 region of the 16S rRNA gene. The PCR product was sequenced on the MiSeq platform. Nineteen bacterial phyla were detected, of which Proteobacteria was the most abundant (51.0 72.5 %), Bacteroidetes (3.6 23.3 %), Firmicutes (4.2 13.7 %), Actinobacteria (1.9 12.1 %), and Planctomycetes (1.3 9.5 %). Diet was the most influential factor in the taxonomic composition of the microbiota, while genetic line was not a strong influential factor. The results suggest that the taxonomic profile of the bacteria colonizing shrimp hepatopancreas was determined by the diet consumed, similar to what occurs in the intestine. Shrimp in the fast-growth line had greater feeding efficiency regardless of the diet supplied. Finally, the results suggest that Proteobacteria influenced (p < 0.05) the feeding efficiency of shrimp fed with a vegetable diet. Nevertheless, further studies are required to explore how shrimp genetic linediet interaction influences microbiota for probiotic development and functional food formulation for farmed shrimp according to the genetic line.(AU)

Effect of dietary protein and genetic line of Litopenaeus vannamei on its hepatopancreatic microbiota

Host genetics and diet can exert an influence on microbiota and, therefore, on feeding efficiency. This study evaluated the effect of genetic line (fast-growth and high-resistance) in Pacific white shrimp (Litopenaeus vannamei) on the hepatopancreatic microbiota and its association with the feeding efficiency in shrimp fed with diets containing different protein sources. Shrimp (2.08 ± 0.06 g) from each genetic line were fed for 36 days with two dietary treatments (animal and vegetable protein). Each of the four groups was sampled, and the hepatopancreatic metagenome was amplified using specific primers for the variable V4 region of the 16S rRNA gene. The PCR product was sequenced on the MiSeq platform. Nineteen bacterial phyla were detected, of which Proteobacteria was the most abundant (51.0 72.5 %), Bacteroidetes (3.6 23.3 %), Firmicutes (4.2 13.7 %), Actinobacteria (1.9 12.1 %), and Planctomycetes (1.3 9.5 %). Diet was the most influential factor in the taxonomic composition of the microbiota, while genetic line was not a strong influential factor. The results suggest that the taxonomic profile of the bacteria colonizing shrimp hepatopancreas was determined by the diet consumed, similar to what occurs in the intestine. Shrimp in the fast-growth line had greater feeding efficiency regardless of the diet supplied. Finally, the results suggest that Proteobacteria influenced (p < 0.05) the feeding efficiency of shrimp fed with a vegetable diet. Nevertheless, further studies are required to explore how shrimp genetic linediet interaction influences microbiota for probiotic development and functional food formulation for farmed shrimp according to the genetic line.

Target hazard quotient evaluation of selected trace elements in highly consumed crustacean species in Lagos, Nigeria

Crustaceans are known for their trace element bioaccumulation abilities. Muscle tissues of lagoon crab, marine crab, pink shrimp and mantis shrimp marketed for consumption in Nigeria were analyzed for Mn, Fe, Cu, Zn, Hg and Cr levels using standard methods. Muscle levels in mg kg-1 of Mn (0.03±0.00 in lagoon crab), Fe (0.072±0.01 in mantis shrimp), Cu (0.344±0.01 in lagoon crab) and Zn (0.073±0.00 in mantis shrimp) were significantly different (p Cu > Zn > Fe > Mn > Cr. Lagoon crab showed the highest total hazard index among the organisms with 44.80 %, while the least was observed in mantis shrimp with 13.30 %. It is concluded that, as far as human health is concerned, the mean elemental levels in the muscle tissues of the organisms examined pose no danger (THQ < 1).

Target hazard quotient evaluation of selected trace elements in highly consumed crustacean species in Lagos, Nigeria

Crustaceans are known for their trace element bioaccumulation abilities. Muscle tissues of lagoon crab, marine crab, pink shrimp and mantis shrimp marketed for consumption in Nigeria were analyzed for Mn, Fe, Cu, Zn, Hg and Cr levels using standard methods. Muscle levels in mg kg-1 of Mn (0.03±0.00 in lagoon crab), Fe (0.072±0.01 in mantis shrimp), Cu (0.344±0.01 in lagoon crab) and Zn (0.073±0.00 in mantis shrimp) were significantly different (p<0.05) from their corresponding values in other examined crustaceans. The mean values of Cr and Hg were not significantly different across samples. The estimated daily intake of trace element (mg person-1day-1) revealed that Hg (0.000001) in marine crab contributed the lowest daily intake while Zn (0.000226) in lagoon crab contributed the highest daily intake. Total hazard quotient (THQ) values for the trace elements followed descending order of Hg > Cu > Zn > Fe > Mn > Cr. Lagoon crab showed the highest total hazard index among the organisms with 44.80 %, while the least was observed in mantis shrimp with 13.30 %. It is concluded that, as far as human health is concerned, the mean elemental levels in the muscle tissues of the organisms examined pose no danger (THQ < 1).(AU)

Dry matter, protein, and energy digestibility of diets for juvenile Pacific white leg shrimps (Litopenaeus vannamei) reared at different salinity levels / Digestibilidade da matéria seca, proteína e energia de dietas para camarão juvenil do Pacífico (Litopenaeus vannamei) cultivadas em diferentes níveis de salinidades

This study evaluated the effect of low, medium, and high-water salinity (5, 35, and 50 ppt) on the apparent dry matter, protein, and energy digestibility of two formulated and six commercial diets for juvenile whiteleg shrimp, Litopenaeus vannamei, in a 120-day trial. Digestibility was determined in vivo using chromic oxide as an inert diet marker. Hydrostability in pellets varied from 86.8% to 99.9%; dry matter digestibility varied from 49.1% to 64.1%; protein digestibility showed greater variations at all salinities (56.9%–85.8%); and energy digestibility ranged from 70.1 to 86.4%. Salinity had a significant effect on dry matter, protein, and energy digestibility. Using a principal component analysis (PCA) with a covariance matrix, our findings suggested that the E2 (fishmeal-based formulation) diet and 35 ppt salinity provided optimum hydrostability and digestibility to Pacific white leg shrimp juveniles.

Nós medimos o efeito de baixa, normal e alta salinidade (5, 35 e 50ppt) na digestibilidade aparente da matéria seca, proteína e energia em duas dietas formuladas e seis comerciais para camarão juvenil do Pacífico, Litopenaeus vannamei. Os coeficientes de digestibilidade aparente da matéria seca, proteína e energia foram determinados in vivo utilizando o óxido crômico como marcador inerte nas dietas (peso inicial médio de 4g), em um teste de 120 dias. Hidrostabilidade na dieta de 86,8% a 99,9%, os coeficientes de digestibilidade da matéria seca variaram de 49,1 a 64,1%, os coeficientes de digestibilidade da proteína apresentaram maiores variações em todas as salinidades (56,9-85,8%), enquanto os coeficientes de digestibilidade da energia variaram de 70,1 a 86,4%. Efeito significativo da salinidade na digestibilidade da matéria seca, proteína e energia foi encontrado. Esses resultados, usando a análise de componentes principais (PCA) com a matriz de covariância, sugerem que a dieta E2 (fórmula à base de farinha de peixe) e salinidade a 35 ppt é ideal para a hidrostabilidade e digestibilidade das dietas para juvenis de camarão-branco-do-Pacífico.

Dry matter, protein, and energy digestibility of diets for juvenile Pacific white leg shrimps (Litopenaeus vannamei) reared at different salinity levels / Digestibilidade da matéria seca, proteína e energia de dietas para camarão juvenil do Pacífico (Litopenaeus vannamei) cultivadas em diferentes níveis de salinidades

This study evaluated the effect of low, medium, and high-water salinity (5, 35, and 50 ppt) on the apparent dry matter, protein, and energy digestibility of two formulated and six commercial diets for juvenile whiteleg shrimp, Litopenaeus vannamei, in a 120-day trial. Digestibility was determined in vivo using chromic oxide as an inert diet marker. Hydrostability in pellets varied from 86.8% to 99.9%; dry matter digestibility varied from 49.1% to 64.1%; protein digestibility showed greater variations at all salinities (56.9%–85.8%); and energy digestibility ranged from 70.1 to 86.4%. Salinity had a significant effect on dry matter, protein, and energy digestibility. Using a principal component analysis (PCA) with a covariance matrix, our findings suggested that the E2 (fishmeal-based formulation) diet and 35 ppt salinity provided optimum hydrostability and digestibility to Pacific white leg shrimp juveniles.(AU)

Nós medimos o efeito de baixa, normal e alta salinidade (5, 35 e 50ppt) na digestibilidade aparente da matéria seca, proteína e energia em duas dietas formuladas e seis comerciais para camarão juvenil do Pacífico, Litopenaeus vannamei. Os coeficientes de digestibilidade aparente da matéria seca, proteína e energia foram determinados in vivo utilizando o óxido crômico como marcador inerte nas dietas (peso inicial médio de 4g), em um teste de 120 dias. Hidrostabilidade na dieta de 86,8% a 99,9%, os coeficientes de digestibilidade da matéria seca variaram de 49,1 a 64,1%, os coeficientes de digestibilidade da proteína apresentaram maiores variações em todas as salinidades (56,9-85,8%), enquanto os coeficientes de digestibilidade da energia variaram de 70,1 a 86,4%. Efeito significativo da salinidade na digestibilidade da matéria seca, proteína e energia foi encontrado. Esses resultados, usando a análise de componentes principais (PCA) com a matriz de covariância, sugerem que a dieta E2 (fórmula à base de farinha de peixe) e salinidade a 35 ppt é ideal para a hidrostabilidade e digestibilidade das dietas para juvenis de camarão-branco-do-Pacífico.(AU)

Dry matter, protein, and energy digestibility of diets for juvenile Pacific white leg shrimps (Litopenaeus vannamei) reared at different salinity levels

ABSTRACT: This study evaluated the effect of low, medium, and high-water salinity (5, 35, and 50 ppt) on the apparent dry matter, protein, and energy digestibility of two formulated and six commercial diets for juvenile whiteleg shrimp, Litopenaeus vannamei, in a 120-day trial. Digestibility was determined in vivo using chromic oxide as an inert diet marker. Hydrostability in pellets varied from 86.8% to 99.9%; dry matter digestibility varied from 49.1% to 64.1%; protein digestibility showed greater variations at all salinities (56.9%-85.8%); and energy digestibility ranged from 70.1 to 86.4%. Salinity had a significant effect on dry matter, protein, and energy digestibility. Using a principal component analysis (PCA) with a covariance matrix, our findings suggested that the E2 (fishmeal-based formulation) diet and 35 ppt salinity provided optimum hydrostability and digestibility to Pacific white leg shrimp juveniles.

RESUMO: Nós medimos o efeito de baixa, normal e alta salinidade (5, 35 e 50ppt) na digestibilidade aparente da matéria seca, proteína e energia em duas dietas formuladas e seis comerciais para camarão juvenil do Pacífico, Litopenaeus vannamei. Os coeficientes de digestibilidade aparente da matéria seca, proteína e energia foram determinados in vivo utilizando o óxido crômico como marcador inerte nas dietas (peso inicial médio de 4g), em um teste de 120 dias. Hidrostabilidade na dieta de 86,8% a 99,9%, os coeficientes de digestibilidade da matéria seca variaram de 49,1 a 64,1%, os coeficientes de digestibilidade da proteína apresentaram maiores variações em todas as salinidades (56,9-85,8%), enquanto os coeficientes de digestibilidade da energia variaram de 70,1 a 86,4%. Efeito significativo da salinidade na digestibilidade da matéria seca, proteína e energia foi encontrado. Esses resultados, usando a análise de componentes principais (PCA) com a matriz de covariância, sugerem que a dieta E2 (fórmula à base de farinha de peixe) e salinidade a 35 ppt é ideal para a hidrostabilidade e digestibilidade das dietas para juvenis de camarão-branco-do-Pacífico.

Effect of chitosan on the mycelial growth of Fusarium oxysporum, Rhizoctonia solani and Trichoderma spp / Efeito da quitosana no crescimento micelial de Fusarium oxysporum, Rhizoctonia solani e Trichoderma spp

Fungicides, often used in conventional farming systems, can harm humans, animals and damage the environment. Chitosan, which is extracted from the crustacean shell, has shown to be a harmless and cheap alternative to fungicides. This study aimed to test the inhibitory effect of chitosan on the mycelial growth of Fusarium oxysporum, Rhizoctonia solani and Trichoderma spp. Different concentrations of chitosan (0, 1, 2, 4, 8 and 16%) were supplemented to 1% acetic acid Potato Dextrose Agar (PDA). The fungi were inoculated in the center of the plates, incubated at 25 °C, with or without a 12-hour photoperiod. Daily measurements were performed in two transverse diameters until the mycelium reached the edges of the Petri dish. Fusarium oxysporum mycelial growth was significantly inhibited by chitosan at concentrations 1, 2, 4, and 8%, on the 4th, 5th and 6th evaluation days, in a 12-hour photoperiod. However, for Rhizoctonia solani, there was no reduction on mycelial growth. Trichoderma spp. presented the greatest mycelial reduction, in both light schemes, in all the concentrations evaluated, on days one, two and three. The results indicate that the mycelial growth of Fusarium oxysporum and Trichoderma spp. were inhibited by chitosan. Although, the combined use of chitosan and Trichoderma spp. as biocontrol agents of phytopathogens is not indicated.

Os fungicidas, frequentemente utilizados em sistemas agrícolas convencionais, podem prejudicar seres humanos, animais e danificar o meio ambiente. A quitosana, extraída da casca do crustáceo, tem se mostrado uma alternativa inofensiva e barata aos fungicidas. Este trabalho teve como objetivo testar o efeito inibitório da quitosana sobre o crescimento micelial de Fusarium oxysporum, Rhizoctonia solani e Trichoderma spp. Diferentes concentrações de quitosana (0,1, 2, 4, 8 e 16%) foram adicionadas em Batata Dextrose Agar (BDA) preparado em 1% de ácido acético. Os fungos foram inoculados no centro das placas,incubados a 25 °C, com ou sem fotoperíodo de 12 horas. Medições diárias foramrealizadas em dois diâmetros transversais até o micélio atingir as bordas da placade Petri. O crescimento micelial de Fusarium oxysporum foi significativamente inibido pela quitosana nas concentrações 1, 2, 4 e 8%, nos dias 4, 5 e 6 deavaliação, em fotoperíodo de 12 horas. No entanto, para Rhizoctonia solani não houve redução no crescimento micelial. Trichoderma spp. apresentou a maior redução micelial, em ambos os esquemas de luz, em todas as concentrações avaliadas, nos dias um, dois e três. Os resultados indicam que o crescimento micelial de Fusarium oxysporum e Trichoderma spp. foram inibidos pela quitosana. Assim, o uso combinado de quitosana e Trichoderma spp. como agentes de biocontrole de fitopatógenos não é indicado.

Effect of chitosan on the mycelial growth of Fusarium oxysporum, Rhizoctonia solani and Trichoderma spp / Efeito da quitosana no crescimento micelial de Fusarium oxysporum, Rhizoctonia solani e Trichoderma spp

Fungicides, often used in conventional farming systems, can harm humans, animals and damage the environment. Chitosan, which is extracted from the crustacean shell, has shown to be a harmless and cheap alternative to fungicides. This study aimed to test the inhibitory effect of chitosan on the mycelial growth of Fusarium oxysporum, Rhizoctonia solani and Trichoderma spp. Different concentrations of chitosan (0, 1, 2, 4, 8 and 16%) were supplemented to 1% acetic acid Potato Dextrose Agar (PDA). The fungi were inoculated in the center of the plates, incubated at 25 °C, with or without a 12-hour photoperiod. Daily measurements were performed in two transverse diameters until the mycelium reached the edges of the Petri dish. Fusarium oxysporum mycelial growth was significantly inhibited by chitosan at concentrations 1, 2, 4, and 8%, on the 4th, 5th and 6th evaluation days, in a 12-hour photoperiod. However, for Rhizoctonia solani, there was no reduction on mycelial growth. Trichoderma spp. presented the greatest mycelial reduction, in both light schemes, in all the concentrations evaluated, on days one, two and three. The results indicate that the mycelial growth of Fusarium oxysporum and Trichoderma spp. were inhibited by chitosan. Although, the combined use of chitosan and Trichoderma spp. as biocontrol agents of phytopathogens is not indicated.(AU)

Os fungicidas, frequentemente utilizados em sistemas agrícolas convencionais, podem prejudicar seres humanos, animais e danificar o meio ambiente. A quitosana, extraída da casca do crustáceo, tem se mostrado uma alternativa inofensiva e barata aos fungicidas. Este trabalho teve como objetivo testar o efeito inibitório da quitosana sobre o crescimento micelial de Fusarium oxysporum, Rhizoctonia solani e Trichoderma spp. Diferentes concentrações de quitosana (0,1, 2, 4, 8 e 16%) foram adicionadas em Batata Dextrose Agar (BDA) preparado em 1% de ácido acético. Os fungos foram inoculados no centro das placas,incubados a 25 °C, com ou sem fotoperíodo de 12 horas. Medições diárias foramrealizadas em dois diâmetros transversais até o micélio atingir as bordas da placade Petri. O crescimento micelial de Fusarium oxysporum foi significativamente inibido pela quitosana nas concentrações 1, 2, 4 e 8%, nos dias 4, 5 e 6 deavaliação, em fotoperíodo de 12 horas. No entanto, para Rhizoctonia solani não houve redução no crescimento micelial. Trichoderma spp. apresentou a maior redução micelial, em ambos os esquemas de luz, em todas as concentrações avaliadas, nos dias um, dois e três. Os resultados indicam que o crescimento micelial de Fusarium oxysporum e Trichoderma spp. foram inibidos pela quitosana. Assim, o uso combinado de quitosana e Trichoderma spp. como agentes de biocontrole de fitopatógenos não é indicado.(AU)

Utilization of rice byproducts as carbon sources in high-density culture of the Pacific white shrimp, Litopenaeus vannamei

This study was conducted to evaluate the effect of rice byproducts on water quality, microbial community, and growth performance of L. vannamei juveniles. Shrimp of 0.98±0.10 g body weight (BW) were reared in 49 tanks of 1.5 m3 under 127 animals m−2 for 77 days. Rice bran, rice grits, and rice hulls were mixed into five different fertilizers varying their fiber content (90, 110, 150, 200, and 250 g kg−1) and compared against sugarcane molasses (MO) and unfertilized tanks (UNF). Rice byproducts and MO were applied in water three times a week at a fixed rate of 4.5 g m−3. Water salinity, pH, temperature, and dissolved oxygen reached 43±2 g L−1, 8.03±0.32, 30.2±0.90 °C, and 5.03±0.53 mg L−1, respectively. Settleable solids (SS) were higher in tanks fertilized with rice byproducts (from 2.5±1.0 to 3.1±1.1 mL L−1) and MO (3.4±1.0 mL L−1). Total ammonia nitrogen (0.19±0.09 mg L−1), nitrite (5.97±2.04 mg L−1), and nitrate (1.29±0.48 mg L−1) were kept low without any significant differences among treatments. The concentration of heterotrophic bacteria and fungi was significantly higher in rice byproducts compared with MO. Water fertilization had no effect on final shrimp survival (85.5±9.5%), weekly growth (0.72±0.11 g), and feed conversion ratio (1.59±0.10). Tanks treated with rice byproducts, except with 90 g kg−1 fiber, resulted in a higher final shrimp BW (from 9.04±1.56 to 9.52±1.89 g) compared with MO (8.75±2.14 g) and UNF (7.74±1.48 g). Gained yield and feed intake were significantly higher for tanks treated with rice byproducts than with UNF. A mix of rice byproducts can be equally or more effective as carbon sources to shrimp culture than MO.(AU)

Preparo de água superoxigenada com peróxido de hidrogênio para uso emergencial em tanques de aquicultura / Making of super oxygenated water with hydrogen peroxide for emergency use in aquaculture tanks

O presente trabalho teve por objetivo produzir água superoxigenada, quimicamente estável, com peróxido de hidrogênio para uso emergencial em tanques de aquicultura. Vinte e quatro galões de 12 L receberam, cada um, 10 L de água doce limpa. Os galões do grupo-controle não receberam nenhuma aplicação de peróxido de hidrogênio 35% p.a. (P35). Os galões dos grupos experimentais receberam uma aplicação única de P35, no início do trabalho, em diferentes dosagens: 2,0 mL P35 L-1 e 4,0 mL P35 L-1. Após a aplicação do produto na água, os galões foram mantidos hermeticamente fechados, sendo que metade dos galões foram abertos periodicamente, por ocasião das amostragens experimentais (galões manipulados), e metade dos galões somente foram abertos nos dias 15 e 28 (galões não manipulados). Determinações de temperatura, pH e concentração de O2 dissolvido na água foram realizadas em todos os galões manipulados, a cada dois dias, nos primeiros 15 dias, e a cada 3-4 dias, do 16° ao 28° dia. Concluiu-se que é possível preparar água superoxigenada quimicamente estabilizada para uso emergencial em tanques de aquicultura pela aplicação de 2,0 mL L-1 de peróxido de hidrogênio 35% p.a, em água doce limpa. Após o preparo, deve-se respeitar uma carência mínima de três dias para uso da água superoxigenada. Concentrações dissolvidas de O2 superiores a 15 mg L-1 poderão ser mantidas por no mínimo 28 dias, caso a vedação dos galões contendo água oxigenada seja apropriada.

The present work aimed at producing chemically stable super oxygenated water with hydrogen peroxide for emergency use in aquaculture tanks. Twenty-four gallons of 12-L each received 10 L of clean freshwater. The control group gallons did not receive any application of hydrogen peroxide 35% p.a. (P35). The experimental group gallons received one single application of P35 at the beginning, in different levels: 2.0 mL P35 L-1 and 4.0 mL P35 L-1. After product applications, the gallons were kept hermetically locked, but half of the gallons were periodically unlocked to take water samples (manipulated gallons), and half were unlocked only at the day 15 and 28 (unmanipulated gallons). Measuring of temperature, pH and dissolved O2 were carried out in all manipulated gallons every two days, in the first 15 days, and every 3-4 days from the 16th to the 28th day. It was concluded that it is possible to prepare chemically stable super oxygenated water for emergency use in aquaculture tanks by applying 2.0 mL L-1 of hydrogen peroxide 35% p.a in clear freshwater. A minimal period of three days must be observed before using the super oxygenated water. Concentrations of dissolved O2 higher than 15 mg L-1 could be obtained for at least 28 days if the water gallons are properly locked up.