Use of antioxidants and time of cold storage: effects over viability parameters and enzymatic levels in semen of rainbow trout (Oncorhynchus mykiss, Walbaum, 1792) / Uso de antioxidantes e tempo de armazenamento a frio: efeitos sobre parâmetros de viabilidade e níveis enzimáticos no sêmen da truta arco-íris (Oncorhynchus mykiss, Walbaum, 1792)

Abstract The cold storage of milt implies potentials alterations in its quality because the storage generates as main process, free radicals that produce spermatozoa membrane lipids damage with the consequent motility and fertilising capacity disruptions. To decrease the damage generated by free radicals the cells have antioxidant defences (proteins, enzymes, and low molecular weight substances). The objective of the present study evaluated the time storage effect and different antioxidants prepared in spermatic diluents on sperm viability of O. mykiss milt stored at 4°C. The two-way ANOVA denoted that the time storage and antioxidant influence have significant effects separated or combined on viability parameters (sperm motility and viability, proteins concentrations and superoxide dismutase enzymatic activity in seminal plasma). In contrast, only the storage time affected the fertilising capacity and catalase enzymatic activity in seminal plasma. The resulting analysis can conclude that the antioxidant presence improves the viability of cold stored milt, especially the transport conditions and the antioxidants allow the fecundity despite motility decrease.

Resumo O armazenamento a frio de leite implica potenciais alterações em sua qualidade, pois gera como processo principal radicais livres que provocam danos aos lipídios da membrana dos espermatozoides, com as consequentes alterações na motilidade e na capacidade de fertilização. Para diminuir os danos causados pelos radicais livres, as células têm defesas antioxidantes (proteínas, enzimas e substâncias de baixo peso molecular). O presente estudo avaliou o efeito do tempo de armazenamento e diferentes antioxidantes preparados em diluentes espermáticos no armazenamento de viabilidade de O. mykiss milt a 4°C. A ANOVA de duas vias denotou que o armazenamento no tempo e a influência antioxidante têm efeitos significativos separados ou combinados nos parâmetros de viabilidade (motilidade espermática, viabilidade espermática, concentrações de proteínas e atividade enzimática da superóxido dismutase no plasma seminal), enquanto apenas o tempo de armazenamento afetou a capacidade de fertilização e atividade enzimática da catalase no plasma seminal. A análise resultante pode concluir que a presença de antioxidante melhora a viabilidade do leite frio, especialmente as condições de transporte, e os antioxidantes permitem a fecundidade apesar da diminuição da motilidade.

Use of antioxidants and time of cold storage: effects over viability parameters and enzymatic levels in semen of rainbow trout (Oncorhynchus mykiss, Walbaum, 1792) / Uso de antioxidantes e tempo de armazenamento a frio: efeitos sobre parâmetros de viabilidade e níveis enzimáticos no sêmen da truta arco-íris (Oncorhynchus mykiss, Walbaum, 1792)

The cold storage of milt implies potentials alterations in its quality because the storage generates as main process, free radicals that produce spermatozoa membrane lipids damage with the consequent motility and fertilising capacity disruptions. To decrease the damage generated by free radicals the cells have antioxidant defences (proteins, enzymes, and low molecular weight substances). The objective of the present study evaluated the time storage effect and different antioxidants prepared in spermatic diluents on sperm viability of O. mykiss milt stored at 4°C. The two-way ANOVA denoted that the time storage and antioxidant influence have significant effects separated or combined on viability parameters (sperm motility and viability, proteins concentrations and superoxide dismutase enzymatic activity in seminal plasma). In contrast, only the storage time affected the fertilising capacity and catalase enzymatic activity in seminal plasma. The resulting analysis can conclude that the antioxidant presence improves the viability of cold stored milt, especially the transport conditions and the antioxidants allow the fecundity despite motility decrease.

O armazenamento a frio de leite implica potenciais alterações em sua qualidade, pois gera como processo principal radicais livres que provocam danos aos lipídios da membrana dos espermatozoides, com as consequentes alterações na motilidade e na capacidade de fertilização. Para diminuir os danos causados pelos radicais livres, as células têm defesas antioxidantes (proteínas, enzimas e substâncias de baixo peso molecular). O presente estudo avaliou o efeito do tempo de armazenamento e diferentes antioxidantes preparados em diluentes espermáticos no armazenamento de viabilidade de O. mykiss milt a 4°C. A ANOVA de duas vias denotou que o armazenamento no tempo e a influência antioxidante têm efeitos significativos separados ou combinados nos parâmetros de viabilidade (motilidade espermática, viabilidade espermática, concentrações de proteínas e atividade enzimática da superóxido dismutase no plasma seminal), enquanto apenas o tempo de armazenamento afetou a capacidade de fertilização e atividade enzimática da catalase no plasma seminal. A análise resultante pode concluir que a presença de antioxidante melhora a viabilidade do leite frio, especialmente as condições de transporte, e os antioxidantes permitem a fecundidade apesar da diminuição da motilidade.

Evaluación de la mineralización en mandíbula y diente de trucha arcoíris (Oncorhynchus mykiss) mediante microscopía electrónica de barrido de presión variable acoplada a detector de espectroscopía de rayos X de energía dispersiva / Evaluation of mineralization in jaw and teeth of rainbow trout (Oncorhynchus mykiss) using variable pressure scanning electron microscopy coupled to energy-dispersive X-ray spectroscopy detector

RESUMEN: En salmonicultura se utilizan imágenes de rayos X, para evaluar la columna vertebral y las aletas, pero estas no permiten cuantificar los minerales que constituyen el hueso, para esto se utilizan otras técnicas que son destructivas. La Microscopía Electrónica de Barrido de presión variable (VP SEM) acoplada al detector espectroscopia de rayos X de energía dispersiva (EDX) acoplado, nos permite analizar la microestructura y a la vez determinar elementos químicos, porcentaje y distribución presentes en puntos específicos en una muestra. Se utilizaron 5 truchas control y 5 con deformidad mandibular, de agua dulce en etapa de smolt, se analizó la estructura y mineralización del hueso, se eligieron en promedio 6 puntos de cuantificación por región de interés y se analizaron mediante Microscopía Electrónica de Barrido (VP SEM-EDX). Los datos obtenidos muestran porcentaje en masa de Ca promedio en hueso articular de truchas fueron de 8.07 % y de 14.48 % en truchas con deformidad mandibular y control respectivamente y el porcentaje en masa promedio de P es de 4.07 % y 7.60 %, en truchas con deformidad mandibular y control respectivamente. Se identificó además otros elementos presentes en la muestra como Mg, Na, C, O, N, S, F, Zn, Al y Fe, con especial interés en el aumento de carbono en las muestras analizadas con deformidad mandibular y la presencia de aluminio en todas las muestras. La Técnica de VP SEM-EDX, permite evaluar de forma directa, sin destrucción de la muestra y con una preparación mínima de la muestra. En el hueso, la aplicación más frecuente de SEM-EDX es la medición del contenido de Ca y P y la relación que existe entre estos elementos Ca/P, en la muestra. Paralelamente la técnica nos permite la detección de otros microelementos provenientes del agua o de la alimentación y que eventualmente pueden provocar alteraciones en los peces, confirmando la hipótesis que el microanálisis elemental tiene utilidad para la salmonicultura.

SUMMARY: In salmon farming systems, X-ray images are used to evaluate the spine and fins, but these do not allow quantifying the minerals that make up the bone, for different techniques that are destructive are used. Variable Pressure Scanning Electron Microscopy (VP SEM) coupled to an Energy Dispersive X-ray spectroscopy detector (EDX), allows us to analyze the microstructure and at the same time determine chemical elements, percentages, and distribution present at specific points in a sample. Five control and five jaw deformity trout, from freshwater and in the smolt stage were used. The structure and mineralization of the bone were analyzed, an average six quantification points were chosen per region of interest (ROI) and then they were analyzed by Scanning Electron Microscopy (VP SEM-EDX). The data obtained have shown the average mass percentage of calcium in trout joint bone was 8.07 % and 14.48 % in jaw deformity and control trout, respectively; and the average mass percentage of phosphorus is 4.07 % and 7.60 %, in jaw deformity and control trout, respectively. Other elements present in the sample were also identified, such as magnesium, sodium, carbon, oxygen, nitrogen, sulphur, fluorine, zinc, aluminium, and iron, with special interest the increase of carbon in the analyzed samples with mandibular deformity and the presence of aluminum in all samples. The VP SEM-EDX Technique allows direct evaluation, without destruction of the sample and with minimal sample preparation. In bone, the most frequent application of SEM-EDX is the measurement of the content of calcium (Ca) and phosphorus (P) and the relationship that exists between these elements, calcium/phosphorus (Ca/P), in the sample. At the same time, the technique allows us to detect other microelements from water or food that can eventually cause alterations in fish, confirming the hypothesis that elemental microanalysis is useful for salmon farming.

Obtención y evaluación de concentrado proteico hidrolizado de residuos animales como alternativa de alimentación en Piaractus brachypomus (Cuvier 1818) / Obtaining and evaluating hydrolyzed protein concentrate from animal waste as a feeding alternative in Piaractus brachypomus (Cuvier 1818)

RESUMEN En la industria acuícola, se vienen desarrollando acciones encaminadas a buscar fuentes proteicas alternativas palatables y de alto valor biológico para reemplazar las fuentes convencionales. Debido al potencial nutricional de los subproductos animales, se han adoptado tecnologías para su uso, como las técnicas de bioconversión por hidrólisis enzimática. En consecuencia, el objetivo de este estudio fue obtener y evaluar un concentrado de proteína hidrolizada de residuos animales (CPHRA) como alternativa en dietas para Piaractus brachypomus. Las vísceras de los subproductos avícolas se evaluaron utilizando ácido fórmico y vísceras de trucha al 20% para promover la hidrólisis enzimática a un pH más bajo (pH 3,66). El producto resultante se utilizó en la formulación de dietas para determinar coeficiente de digestibilidad aparente (CDA) de energía y nutrientes, utilizando una dieta control () y tres dietas con inclusión de 10%, 20% y 30% de CPHRA (T1, T2 y T3). Se alimentaron por triplicado ciento veinte juveniles de híbridos de cachama blanca con un peso promedio de 145 ± 3,0 g. La CPHRA presentó alto contenido proteico y se evidenciaron diferencias significativas (p < 0,05) para los CDA de materia seca, proteína bruta, grasa bruta, energía bruta y absorción de cenizas, calcio y fósforo. Los CDA de nutrientes y energía estaban por encima del 80%. En consecuencia, el concentrado de proteína hidrolizada de los desechos de aves de corral tiene un gran potencial como alternativa proteica y energética de alto valor nutricional en la alimentación de los peces.

ABSTRACT The aquaculture industry aims to find new strategies to replace fishmeal in formulated diet-sources with high attraction and palatability and high biological value to replace conventional sources. Due to the nutritional potential of animal by-products, technologies have been adopted for their use, such as bioconversion techniques by enzymatic hydrolysis. Consequently, the objective of this study was obtaining and evaluating a hydrolyzed protein concentrate of animal waste (CPHRA, by its Spanish acronym) in diets for Piaractus brachypomus. Viscera from poultry by-products was evaluated by using formic acid and a 20% trout viscera to promote the catalyst at lower pH (3,66). The resulting product was used in feed formulation to determine the Apparent Digestibility Coefficient (ADC) of energy and nutrients, using a control diet (T0) and three diets with 10%, 20%, and 30% CPHRA (T1, T2 y T3). One hundred and twenty juveniles of hybrids of cachama blanca with an average weight of 145 ± 3,0 g were fed in triplicate groups. The CPHRA presented high protein content and significant differences (p < 0,05) were evidenced for the ADCs of dry matter, crude protein, crude fat, crude energy, and ash absorption, calcium and phosphorus. The ADCs for nutrients and energy were above 80%. Accordingly, the hydrolyzed protein concentrate from poultry waste has great potential as a protein and energy alternative of high nutritional value in fish feeding.

Fish products developed from ground rainbow trout and tilapia fillet mixtures: physico-chemical, microbiological and toxicological analyses / Produtos de pescado elaborados a partir de misturas de carne moída de truta-arco-íris (Oncorhynchus mykiss) e tilápia (Oreochromis sp. ): análises físico-químicas, microbiológicas e toxicológicas

Constant fishing industry innovations in response to consumer demands for novel, balanced healthy products exhibiting high nutritional value, as well as easy to prepare and ready to consume, have led to the emergence of new technologies. Among them, the development of products based on ground beef and fish mixtures are noteworthy. In this context, the purpose of this study was to develop products from different ground rainbow trout and tilapia fillet ratios, in the form of meatballs and nuggets, determining their proximate composition and physico-chemical, microbiological and toxicological characteristics. The average dry matter percentage of the developed products was 29.20±2.30%, while mineral content was 1.45±0.55%, lipid pulp content, 3.70±0.30% and crude pulp protein, 16.60±2.04%. Total psychotropic counts remained below 102 CFU/g, for standard counting on aerobic microorganism plates. Histamine and sulfur-based compounds were not detected in any of the prepared samples. The purpose of the work proposal was to develop foods and technologies that can serve as standards, allowing for simple handling products that apply ground meat mixtures from different fish species to maintain adequate nutritional indices after processing.(AU)

A constante inovação da indústria pesqueira, em resposta às demandas dos consumidores por novos produtos saudáveis, com alto valor nutritivo, balanceados, de fácil preparo e prontos para consumo, levou ao surgimento de novas tecnologias, entre elas o desenvolvimento de produtos à base de mistura de carne moída de pescado. Nesse contexto, a proposta deste trabalho é desenvolver produtos a partir de carne moída de pescado de truta-arco-íris e tilápia, confeccionando almôndegas e nuggets em diferentes proporções, com determinação da composição centesimal e de suas características físico-químicas, microbiológicas e toxicológicas. A matéria seca percentual média foi de 29,20±2,30%. Teores de matéria mineral nos produtos estão em 1,45±0,55%. Os teores de lipídeos aferidos na polpa foram de 3,70±0,30%, e os níveis de proteína bruta apresentados na polpa de 16,60±2,04%. A contagem de psicrotróficos totais manteve-se abaixo de 102 CFU/g, para contagem padrão em placas de micro-organismos aeróbicos. Nas amostras, não foram detectados níveis de histamina e de compostos à base de enxofre. A proposta de trabalho objetivou, por fim, desenvolver alimentos e tecnologias que possam servir como padrões, permitindo que produtos de manipulação simples e que utilizem misturas de carne moída de diferentes espécies de pescado mantenham índices nutricionais adequados após o processamento.(AU)

Investigation of the effects of some phytochemicals on Yersinia ruckeri and antimicrobial resistance / Investigação dos efeitos de alguns fitoquímicos em Yersinia ruckeri e resistência antimicrobiana

Abstract In this study, it is aimed to investigate the effects of Moringa oleifera and Sorbus domestica plant extracts on bacterial disease agents Yersinia ruckeri in aquaculture. Morphological and biochemical properties of 2 different Y. ruckeri isolates were determined. Then, Real-Time PCR analysis and gene sequencing of the isolates were identified. Phytochemicals (M. oleifera and S. domestica) and antibiotics (Oxytetracycline (OX) and Enrofloxacin (ENR)) were used together in the antibiogram test of antibiotics compared to the effect status of antibiotics. Also, the effects of phytochemicals on Y. ruckeri growth was examined comparatively by spectrophotometrically measuring at 600 nm wavelength every 2 hours according to bacterial growth densities with 10 different groups formed on TSB medium. As a result of the study, it was observed that the isolates formed Gram negative, catalase positive, oxidase negative, mobile and typical Y. ruckeri colonies. After the biochemical tests performed with Microgen ID panel, 99.85% similarity was determined. The isolates overlap with the 16S rRNA gene region after sequence analysis, and 99% of the isolates were similar in phylogenetic analysis. After the antibiogram test, Oxytetracycline and Enrofloxacin antibiotics were resistant to Y. ruckeri but the effects of phytochemicals were less on solid medium (MHA). As a result of the measurements carried out in liquid medium (TSB), it was observed that phytochemicals such as M. oliefera and S. domestica inhibit the growth of bacteria by 40-50%. As the importance of antibiotic resistance is increasing day by day, we believe that these phytochemicals will give positive results in treatment instead of using antibiotics.

Resumo Neste estudo, objetiva-se investigar os efeitos dos extratos de plantas de Moringa oleifera e Sorbus domestica sobre agentes bacterianos Yersinia ruckeri na aquicultura. Foram determinadas as propriedades morfológicas e bioquímicas de 2 isolados diferentes de Y. ruckeri. Em seguida, a análise de PCR em tempo real e o seqüenciamento genético dos isolados foram identificados. Fitoquímicos (M. oleifera e S. domestica) e antibióticos (Oxitetraciclina e Enrofloxacina) foram usados ​​juntos no teste de antibiograma dos antibióticos em comparação com o status de efeito dos antibióticos. Além disso, os efeitos dos fitoquímicos no crescimento de Y. ruckeri foram examinados comparativamente por medição espectrofotométrica no comprimento de onda de 600 nm a cada 2 horas de acordo com as densidades de crescimento bacteriano com 10 grupos diferentes formados no meio TSB. Como resultado do estudo, observou-se que os isolados formaram colônias Gram-negativas, catalase-positivas, oxidase-negativas, móveis e típicas de Y. ruckeri. Após os testes bioquímicos realizados com o painel Microgen ID, foi determinada uma similaridade de 99,85%. Os isolados se sobrepõem à região do gene 16S rRNA após a análise da sequência e 99% dos isolados foram semelhantes na análise filogenética. Após o teste do antibiograma, os antibióticos Oxitetraciclina e Enrofloxacina foram resistentes a Y. ruckeri, mas os efeitos dos fitoquímicos foram menores no meio sólido (MHA). Como resultado das medições realizadas em meio líquido (TSB), observou-se que os fitoquímicos inibem o crescimento de bactérias em 40-50%. Como a importância da resistência aos antibióticos está aumentando dia a dia, acreditamos que as plantas que são mais alternativas e mais adequadas para o uso de antibióticos hoje em dia darão resultados positivos no tratamento.

Parasitos em trutas-arco-íris (Oncorhynchus mykiss) criadas em sistema intensivo na região serrana de Santa Catarina, Brasil / [Parasites in rainbow trout (Oncorhynchus mykiss) raised in an intensive system in the mountain region of Santa Catarina, Brazil]

With the aim to determine the prevalence and mean parasite intensity in Oncorhynchus mykiss, 120 specimens were analyzed between April and September 2018. The cavity analysis was done by visual inspection, scraping of mucus, and extraction of the branchial arches. In the evisceration process, the intestine, the liver, and the kidney were separated, while the musculature was analyzed using the "candling table" method. All the collected material was preserved in 10% buffered formaldehyde and sent to the Laboratory of Parasitology and Parasitic Diseases, of the Center for Agroveterinary Sciences (CAV) of the University of the State of Santa Catarina (UDESC) for making the slides and identifying the parasites. Parasites were detected only in the analysis of the scraping of body mucus. Only specimens of the genus Trichodina were identified, in 34 of the 120 fish analyzed, in two collections, resulting in a prevalence of 28.33%. In total, 144 specimens of Trichodina were observed. The overall mean intensity was of 4.24 parasites in each fish analyzed. Characteristic lesions of infection by protozoa were not identified. This is the first report of the occurrence of Trichodina spp. in O. mykiss bred in an intensive system in Brazil, with low rates of parasitic infection in the mountain region of Santa Catarina.(AU)

Avaliação da viabilidade de microrganismos probióticos incorporados em ração de truta-arco-íris (Oncorhynchus mykiss) / [Evaluation of the viability of probiotic microorganisms impregnated into rainbow trout (Oncorhynchus mykiss) ration]

A produção aquícola mundial tem demandado estudos que buscam soluções para os problemas produtivos e sanitários apresentados na piscicultura. Nesse contexto, o uso de produtos probióticos demonstra ser uma abordagem promissora. Dessa forma, o presente trabalho teve como objetivo avaliar a viabilidade de um pool de cepas de Lactobacillus incorporados à ração de truta-arco-íris. Para tanto, as respectivas cepas foram previamente cultivadas em caldo MRS e submetidas à criocentrifugação. As células obtidas foram ressuspensas em soro fisiológico acrescentado de 2% de óleo de soja, sendo posteriormente incorporadas à ração por meio de misturador circular. Essa ração foi devidamente armazenada sob refrigeração a 4°C, por 120 dias, sendo retiradas aleatoriamente três amostras, a cada 15 dias, para avaliação da viabilidade das bactérias, por meio da contagem em placas. Os resultados demonstraram que houve uma redução não significativa (P>0,05) na população de células viáveis, correspondente a 2%, após 30 dias de armazenamento. Verificou-se também, após esse período, uma população aproximada equivalente a 3,00 x 108 UFC/g. Dessa forma, demonstrou-se a possibilidade de desenvolvimento de formulações probióticas por meio da incorporação de cepas específicas em rações de trutas, o que poderá contribuir para o desenvolvimento de tecnologias alternativas para produção de peixes.(AU)

Among the exotic species of fish produced in Brazil, the rainbow trout (Oncorhynchus mykiss) has been highlighted during the past few years. The expansion of this sector has been intensifying the need for further studies in order to decrease production and health problems presented in aquaculture, as well as to develop alternative technics to controversial antimicrobial treatments. In this context, the use of probiotics has been shown to be a promising approach to the improvement in trout husbandry. Thus, the present study aimed to contribute to the development of an alternative technology in the rainbow trout husbandry by evaluating the effect of probiotic preparations on the performance of the animals subjected to conventional husbandry conditions or chronic stress. Therefore, in this paper we report the results regarding the evaluation of the viability of a pool of 4 Lactobacillus probiotic strains incorporated into rainbow trout ration using soybean oil as vehicle. The results have demonstrated a high efficacy of cell incorporation into the ration with high viability rate after storage for 120 days at 4°C.(AU)

Assessment and incidence of fish associated bacterial pathogens at hatcheries of Azad Kashmir, Pakistan / Avaliação e incidência de patógenos bacterianos associados a peixes em incubadoras da Caxemira de Azad, Paquistão

Abstract Fish is the most indispensable source of proteins for individuals and have high nutritional value. On the other hand, the fish culturing raised issues of fish health due to close contact between the aquatic environment and the fish pathogens. So, the aim of the current study was to identify the bacterial pathogens and screen the injured Rainbow trout rearing in different trout hatcheries run under fisheries department of the government of Azad Jammu and Kashmir, Pakistan. Seven bacterial pathogens such as Shigella flexneri, Enterobacter amnigenus, Salmonella Typhimurium, Serratia odorifera, Pseudomonas aeruginosa, Streptococcus pyogenes, and Bacillus cereus were isolated and identified. Results revealed that the injury of fish specimens was due to overcrowding. Instead of rainbow coloration, specimens have darker black in color. The water of ponds was not clean and clear and such conditions was because of the greater quantity of feed thrown in the water. It was concluded that poor hygienic water condition and overloading allowed the opportunistic bacterial contaminations to succeed which cause a serious threat to hatcheries.

Resumo O peixe é a fonte mais indispensável de proteínas para os indivíduos e tem alto valor nutricional. Por outro lado, a cultura dos peixes levantou questões sobre a saúde dos peixes devido ao próximo contato entre o ambiente aquático e os agentes patogênicos desses peixes. Assim, o objetivo do presente estudo foi identificar os patógenos bacterianos e rastrear a criação da truta arco-íris que apresentou lesões em diferentes incubadoras de trutas, com supervisão do departamento de pesca do governo de Azad Jammu e Caxemira, Paquistão. Sete patógenos bacterianos foram isolados e identificados, tais como: Shigella flexneri, Enterobacter amnigenus, Salmonella typhimurium, Serratia odorifera, Pseudomonas aeruginosa, Streptococcus pyogenes e Bacillus cereus. Os resultados revelaram que a lesão de espécimes de peixes foi devido à superlotação. Em vez da coloração do arco-íris, os espécimes tiveram uma coloração preta mais escura. A água das lagoas não era limpa e nem clara, e tais condições ocorreram devido a maior quantidade de alimento lançada na água. Concluiu-se que a precária condição higiênica da água e também a sobrecarga permitiram que as contaminações bacterianas oportunistas fossem bem-sucedidas, causando séria ameaça às incubadoras.

Nonlinear regression analysis of length growth in cultured rainbow trout / [Análise não linear do crescimento em comprimento de truta-arco-íris de aquicultura ]

Length growth as a function of time has a non-linear relationship, so nonlinear equations are recommended to represent this kind of curve. We used six nonlinear models to calculate the length gain of rainbow trout (Oncorhynchus mykiss) during the final grow-out phase of 98 days under three different feed types in triplicate groups. We fitted the von Bertalanffy, Gompertz, Logistic, Brody, Power Function, and Exponential equations to individual length-at-age data of 900 fish. Equations were fitted to the data based on the least square method using the Marquardt iterative algorithm. Accuracy of the fitted models was evaluated using a model performance metrics combining mean squared residuals (MSR), mean absolute error (MAE) and Akaike's Information Criterion corrected for small sample sizes (AICc). All models converged in all cases tested. Evaluation criteria for the Logistic model indicated the best overall fit (0.67 of combined metric MSR, MAE and AICc) under all different feeding types, followed by the Exponential model (0.185), and the von Bertalanffy and Brody model (0.074, respectively). Additionally, ∆AICc results identify the Logistic and Gompertz models as being substantially supported by the data in 100% of cases. The logistic model can be suggested for length growth prediction in aquaculture of rainbow trout.(AU)

O crescimento em comprimento em função do tempo tem uma relação não linear; por isso, funções não lineares são recomendáveis para descrever essa relação. Seis modelos não lineares foram usados para calcular o ganho em comprimento de truta-arco-íris (Oncorhynchus mykiss) durante 98 dias, na fase final da engorda, submetidas a três dietas diferentes em grupos triplicados. Foram ajustadas as equações de von Bertalanffy, Gompertz, logístico, Brody, função potencial e exponencial a dados individuais de comprimento-idade de 900 peixes. O ajuste foi feito pelo método dos mínimos quadrados, usando-se o algoritmo iterativo de Marquardt. A precisão do ajuste foi avaliada pelo uso de critérios combinados de ajuste: quadrado médio do resíduo (QMR), erro médio absoluto (EMA) e o critério de informação de Akaike corrigido para tamanhos amostrais pequenos (AICc). Todos os modelos atingiram a convergência para cada caso avaliado. Os critérios de avaliação do modelo logístico indicaram o melhor ajuste geral (0,67 vez dos critérios combinados MSR, MAE e AICc) para cada grupo de peixe avaliado, seguido pelo modelo exponencial (0,185) e os modelos von Bertalanffy e Brody, com 0,074, respectivamente. Similarmente, os resultados de ΔAICc identificaram-se ao modelo logístico e ao de Gompertz, com grande suporte das informações em 100% dos casos. Por fim, o modelo logístico pode ser sugerido na predição do crescimento em comprimento de truta-arco-íris cultivada.(AU)

Proximate and Nutritional Content of Rainbow Trout (Oncorhynchus mykiss) Flesh Cultured in a Tropical Highland Area

Abstract The present study was performed to assess the proximate and nutrient content of rainbow trout flesh, cultured in the Doi Inthanon Fisheries Research Unit, Chiang Mai Inland Fisheries Research and Development Center, Thailand. 240 fish were randomly distributed across 12 cages with 20 fish cage-1. Sixteen individual fish from each cage were randomly collected at different ages of 10, 12 and 24 months. Body composition, pH, water-holding capacity, shear force, collagen content analysis, sensory, lipid oxidation, and fatty acids profile were evaluated. The results indicated that body composition and carcass length were significantly higher in fish aged 24 months, except for carcass and viscero-somatic index percentages (P ≤ 0.05). Fish at 24 months showed significantly higher pH, moisture, fat, shear force, thiobarbituric acid reactive substances, and total collagen content values than fish at 10 and 12 months (P ≤ 0.05). However, protein percentage, sensory measurement and water-holding capacity were significantly higher in younger fish at 10 and 12 months. The average lipid content and n-6/n-3 ratios were significantly greater in fish at 12 months and in ventral fillets (P ≤ 0.05). However, polyunsaturated fatty acids: saturated fatty acid ratio was higher in fish at 24 months and in dorsal fillets. In conclusion, rainbow trout cultured in sub-tropical, montane conditions can be valuable sources of protein, unsaturated fatty acids, eicosapentaenoic acids, and docosahexaenoic acids.

Método do índice de qualidade (MIQ) aplicado em trutas arco-íris (Oncorhynchus mykiss) inteiras e resfriadas oriundas de pesque pague no Estado do Rio de Janeiro, Brasil / Quality index method (QIM) applied to rainbow trout (Oncorhynchus mykiss) whole and refrigerated from pesque pague in the State of Rio de Janeiro, Brazil

Na região serrana do estado do Rio de Janeiro são comuns a prática da truticultura e o consumo dessa espécie de peixe. A aceitação do pescado está estritamente relacionada às características de frescor do mesmo, que pode sofrer alterações devido a processos físico-químicos, microbiológicos e sensoriais de deterioração. Objetivou-se com esse trabalho avaliar o frescor de trutas arco-íris (Oncorhynchus mykiss) e, com isso, desenvolver um padrão específico através da adaptação do Método do Índice de Qualidade (MIQ) para essa espécie, ao longo de 11 dias de armazenamento sob refrigeração. A análise consistiu na avaliação de características determinantes para o frescor das trutas e o registro dos parâmetros foi realizado por meio de um sistema de pontuação de demérito, tendo em vista que quanto menor a pontuação, mais fresco o peixe. Foi concluído que, aos 11 dias, a truta inteira não apresentava aspectos de repugnância ou rejeição de acordo com os parâmetros preconizados pelo RIISPOA.

Parâmetros físico químicos de qualidade em trutas arco-íris (Oncorhynchus mykiss) inteiras e resfriadas: uma discussão fundamentada dos valores oficiais / Quality chemical physical parameters in rainbow trout (Oncorhynchus mykiss) whole and refrigerated: a based discussion of official values

Parâmetros de qualidade de peixes marinhos e dulcícolas tem sido foco de muitas polêmicas, e até alvo de problemas jurídicos em empresas de beneficiamento. Objetivou-se avaliar as alterações físico-químicas de trutas arco-íris por meio de análises de pH, NH3 e BVT, por um período de 10 dias em refrigeração. Foram examinadas 10 trutas inteiras, capturadas em um pesque pague da região serrana do Rio de Janeiro. Após captura, os animais foram eutanasiados e acondicionados em recipiente isotérmico com gelo. Foi avaliado o pH em quatro diferentes porções musculares, analisado também as BVT e NH3. Não foram observadas diferenças significativas dos resultados de pH entre as porções avaliadas, com exceção da ventral. Conclui-se que em 10 dias de armazenamento de trutas inteiras e refrigeradas os parâmetros físico químicos são satisfatórios.

The effect of banana leaf package on the shelf life of rainbow trout fillet in comparison with plastic bag s / O efeito da embalagem de folha de bananeira na vida de prateleira do filé de truta arco-íris em comparação com sacos de plástico

The aim of this study was to evaluate the effect of banana leaf extract on the quality and shelf life of rainbow trout compared to plastic bags at freezing temperature for 40 days. For evaluating this propose, the antioxidant activity of banana leaf extract was assessed. In addition, the shelf life of fish filets was determined by measuring thiobarbituric acid (TBA) and pHof fish. The banana leaves extract showed the highest content of vitamin E (5.8 ± 0.61 mg /g) and carotenoids (12.8 ± 0.1 mg /g). The potential of Cu (II) reduction the extract was 1.76 ± 0.09. The magnitude of modification in TBA and pH of the packed fish with banana leaves were less than the control samples. The present study demonstrated that the use of banana leaf extract will retard lipid oxidation in fish. fillet during freezing storage that may due to its strong antioxidant properties.

O objetivo deste estudo foi avaliar o efeito do extrato de folhas de bananeira sobre a qualidade e vida de prateleira da truta arco-íris comparada a sacolas plásticas na temperatura de congelamento por 40 dias. Para avaliar essa proposta, foi determinada a atividade antioxidante do extrato de folhas de bananeira. Além disso, a vida de prateleira dos filés de peixe foi determinada medindo o ácido tiobarbitúrico (TBA) e o pH do peixe. O extrato de folhas de bananeira apresentou o maior teor de vitamina E (5,8 ± 0,61 mg/g) e carotenóides (12,8 ± 0,1 mg/g). O potencial de redução de Cu (II) no extrato foi de 1,76 ± 0,09. A magnitude da modificação no TBA e pH do peixe embalado com folhas de bananeira foi menor que as amostras controle. O presente estudo demonstrou que o uso de extrato de folhas de bananeira é capaz de retardar a oxidação lipídica no filé de peixe durante o armazenamento de congelamento, devido às suas fortes propriedades antioxidantes.

Saprolegnia parasitica Isolated from Rainbow Trout in Korea: Characterization, Anti-Saprolegnia Activity and Host Pathogen Interaction in Zebrafish Disease Model

Saprolegniasis is one of the most devastating oomycete diseases in freshwater fish which is caused by species in the genus Saprolegnia including Saprolegnia parasitica. In this study, we isolated the strain of S. parasitica from diseased rainbow trout in Korea. Morphological and molecular based identification confirmed that isolated oomycete belongs to the member of S. parasitica, supported by its typical features including cotton-like mycelium, zoospores and phylogenetic analysis with internal transcribed spacer region. Pathogenicity of isolated S. parasitica was developed in embryo, juvenile, and adult zebrafish as a disease model. Host-pathogen interaction in adult zebrafish was investigated at transcriptional level. Upon infection with S. parasitica, pathogen/antigen recognition and signaling (TLR2, TLR4b, TLR5b, NOD1, and major histocompatibility complex class I), pro/anti-inflammatory cytokines (interleukin [IL]-1β, tumor necrosis factor α, IL-6, IL-8, interferon γ, IL-12, and IL-10), matrix metalloproteinase (MMP9 and MMP13), cell surface molecules (CD8⁺ and CD4⁺) and antioxidant enzymes (superoxide dismutase, catalase) related genes were differentially modulated at 3- and 12-hr post infection. As an anti-Saprolegnia agent, plant based lawsone was applied to investigate on the susceptibility of S. parasitica showing the minimum inhibitory concentration and percentage inhibition of radial growth as 200 μg/mL and 31.8%, respectively. Moreover, natural lawsone changed the membrane permeability of S. parasitica mycelium and caused irreversible damage and disintegration to the cellular membranes of S. parasitica. Transcriptional responses of the genes of S. parasitica mycelium exposed to lawsone were altered, indicating that lawsone could be a potential anti-S. parasitica agent for controlling S. parasitica infection.

Effects of levamisole on immune responses and resistance against density stress in rainbow trout fingerling [Oncorhynchus my kiss]

Background: It is necessary to potentiate the immune system of fishes against stresses in farms

Objectives: This study was carried out to address the potential effect of Levamisole on immune system of rainbow trout against density stress

Methods: 1500 fish [average weight of 50 g] were divided into 5 test groups, in which each test group was repeated three times with average density of 33 kg/m[3]. They were fed with commercial diet supplemented with Levamisole at concentrations of 0 [control], 100, 250, 500 and 1000 mg / kg for a period of 45 days. The fishes of all groups were then fed with Levamisole free diet and exposed to 2 and 3-fold density stress for the following 15 days. Blood samples were collected on days 0, 15, 30, 45 and 60 to evaluate the serum compliment and lysozyme activity as well as total immunoglobulins

Results: The results showed that all used concentrations of Levamisole just had significant effect on compliment activity after 45 days feeding period [p<0.05]. Higher levels of lysozyme and complement activity as well as total immunoglobulin were observed in 1000 mg/kg Levamisole treated group when exposed to density stresses 2 and 3-fold at the end of trial [day 60] [p<0.05]. The highest overall survival was found in group which was treated with 1000 mg/kg of Levamisole

Conclusions: Our results revealed that using 0/1% Levamisole as an im-munostimulator in commercial diet could potentiate rainbow trout against outbreak of high density stresses and increase its overall survival

Environmental indicators in effluent assessment of rainbow trout (Oncorhynchus mykiss) reared in raceway system through phosphorus and nitrogen / Indicadores ambientais na avaliação de efluentes de truta arco-íris (Oncorhynchus mykiss) criados em sistema de raceway através do fósforo e nitrogênio

Abstract The phosphorus and nitrogen discharge via effluent of intensive trout farming system was quantified through the use of environmental indicators. The nutrient loads, the mass balance, the estimated amount of nutrients in feed and the amount of nutrients converted in fish biomass were calculated based on the concentrations of phosphorus (P) and nitrogen (N) in the feed and in the water. Of the offered feed, 24.75 kg were available as P and 99.00 kg as N, of these, 9.32 kg P (38%) and 29.12 kg N (25%) were converted into fish biomass and 15.43 kg P (62%) and 69.88 kg N (75%) were exported via effluent. The loads and the mass balance show the excessive discharge of nutrients via effluent, corroborated by the feed conversion ratio (2.12:1) due to the low efficiency of feed utilization, therefore, it is proposed the use of this zootechnical parameter as environmental indicator. In addition, feed management practices are not adequate, highlighting the low frequency of feeding during the day, excessive amount and low quality of feed offered. These results demonstrate the need for adequate feed management and the need for careful monitoring of effluent.

Resumo A descarga de fósforo e nitrogênio via efluente do sistema intensivo de truticultura foi quantificada através da utilização de indicadores ambientais. As cargas de nutrientes, o balanço de massa, a quantidade estimada de nutrientes na ração e a quantidade de nutrientes convertidos em biomassa de peixes foram calculados com base nas concentrações de fósforo (P) e nitrogênio (N) na ração e na água. Da ração oferecida, 24,75 kg estavam disponíveis como P e 99,00 kg como N, destes, 9,32 kg de P (38%) e 29,12 kg de N (25%) foram convertidos em biomassa de peixe e 15,43 kg P (62%) e 69,88 kg N (75%) foram exportados via efluente. As cargas e o balanço de massa mostram a descarga excessiva de nutrientes via efluente, corroborado pela taxa de conversão alimentar (2,12:1), devido à baixa eficiência na utilização da ração, portanto, propõe-se a utilização deste parâmetro zootécnico como indicador ambiental. Além disso, as práticas de manejo alimentar não são adequadas, destacando a baixa frequência de alimentação durante o dia, quantidade excessiva e baixa qualidade da alimentação ofertada. Esses resultados demonstram a necessidade de manejo alimentar adequado e de monitoramento do efluente.

Expressão da enzima indoleamina-2, 3-dioxigenase em truta arco-íris (Oncorhynchus mykiss) / Expression of the enzyme indoleamine-2, 3-dioxygenase in Rainbow Trout (Oncorhynchus mykiss

A indoleamina 2,3-dioxigenase (IDO) é uma enzima que cataboliza o aminoácido triptofano, levando à inibição da proliferação de linfócitos T, seja pela exaustão desse aminoácido no ambiente, ou pela indução via catabólitos induzindo-os a apoptose. Em mamíferos, esta enzima atua em diversas condições do organismo como a gestação, infecções, inflamações crônicas, transplantes e tumores, atuando na regulação imunológica. Estudos recentes identificaram a presença de moléculas homólogas a IDO em espécies filogeneticamente inferiores, cuja função parece estar restrita ao metabolismo do triptofano como fonte de energia. Este estudo teve por objetivo averiguar a expressão da IDO em células sanguíneas e órgãos hematopoiéticos de truta arco-íris pela imuno-histoquímica, buscando evidências de que a mesma poderia, nesta espécie, estar relacionada ao sistema imune. A expressão de IDO foi observada nos órgãos hematopoiéticos estudados incluindo o rim cefálico que apresentou marcação em células interrenais e leucócitos; baço, na qual a marcação restringiu à alguns leucócitos; no fígado a marcação ficou limitada à apenas algumas células dentro dos vasos sanguíneos e nas extensões sanguíneas pode-se visualizar a marcação de alguns leucócitos como os monócitos, linfócitos e neutrófilos. A predominância da marcação da IDO nesses tecidos pode constituir uma evidência de que a IDO identificada na O. mykiss esteja relacionada ao sistema imunológico nessa espécie...

Indoleamine 2,3-dioxygenase (IDO) is an enzyme that catabolizes the amino acid tryptophan, leading to inhibition of T lymphocyte proliferation, whether by depletion of this amino acid in the environment, or by induction via the catabolites inducing apoptosis. In mammals, this enzyme acts on various conditions of the body such as pregnancy, infections, chronic inflammation, transplantation and tumors, acting in immune regulation. Recent studies have identified the presence of homologous molecules IDO lower phylogenetically related species, whose function appears to be confined to the tryptophan metabolism as an energy source. This study aimed to investigate the expression of IDO in blood cells and hematopoietic organs of rainbow trout by immunohistochemistry, seeking evidence that it could, this species is related to the immune system. The expression of IDO was observed in hematopoietic organs studied including head kidney that show labeling in interrenal cells and leukocytes; spleen, in which the marking restricted to a few leukocytes in the liver;, labeling was restricted to only certain cells within the blood vessels and the blood extensions can view the marking of some leukocytes including monocytes, lymphocytes and neutrophils. The predominance of IDO marking these tissues may constitute evidence that IDO identified in O. mykiss is related to the immune system in this species...

Effect of CuO nanoparticles on some hematological indices of rainbow trout oncorhynchus mykiss and their potential toxicity

This study aimed to determine the possible toxicity of Cuo nanoparticles [NPs] on Oncorhynchus mykiss by evaluating hematological parameters. Fish were sampled and treated in 4 aquariums containing the concentration ranges of 1, 5, 20 and 100 ppm of CuO NPs. There was one control group [no CuO NPs] and three replicates. The physicochemical properties of water were as follows: the temperature was 22 +/- 2 C degree, oxygen saturation was 90.9 +/- 0.2%, pH was at 7 +/- 0.004 and the concentration of CaCO3 was 270. No mortality was observed after 96 hours of exposure. The analysis of hematological parameters showed that CuO NPs affected the counts of white blood cells, lymphocytes, eosinophils, neutrophils, hematocrits, MCH, MCHC and MCV and did not have any effects on monocytes and hemoglobins. The data showed that the overall hardness [270 ppm] neutralized the lethal effect of copper on O. mykiss and no mortality was recorded

[Effect of calcium and magnesium ions in the billard salt solution on sperm motility in rainbow trout [Oncorhynchus mykiss, walbaum 1792]]

There are different activating salt solutions for sperm induction of rainbow trout [Oncorhynchus mykiss] under artificial spawning condition, although some uncertainties are associated with the performance. This study was conducted to consider the effects of different concentration of calcium and magnesium ions and change of pH in the Billard salt solution on sperm motility of rainbow trout. Four-year old broodstocks [n=10] of rainbow trout were randomly selected and adapted to the same experimental condition for two weeks. Experimental solutions were also prepared in triplicate by separately adding 1, 2, and 3 mmol calcium and magnesium to the Billard solution. Another three solutions were also prepared with pH adjustment from 9.0 in the Billard solution to 8.0, 8.5, and 9.5. The broodstocks were then transported to the hatchery and artificially spawned. The collected sperm from all broodstocks were mixed for eliminating the effect of genetically differences between the fishes. Finally, the rainbow trout sperm mobility in the experimental treatments was determined in triplicate and compared by the Billard solution as the control treatment. Sperm mobility of rainbow trout in all treatments was significantly more than the control [p<0.01]. The maximum mobility with 105.0 +/- 6.7 s was obtained in the 1 mmol calcium treatment, while the lowest level was found in the Billard treatment [31.33 +/- 4.50 s]. Between the experimental treatments, calcium had the most effect on the sperm mobility of rainbow trout, although no significant differences was observed on the sperm mobility between 3 mmol calcium and 3 mmol magnesium treatments [p<0.01]. A downward trend in sperm mobility was found by increasing the pH of activating solutions with the highest and lowest sperm mobility in the pH of 8 and 9.5 treatments, respectively. The findings of the present study demonstrated that modification of activating salt solutions using each doubly charged ions of calcium and magnesium and the pH adjustment could improve the reproduction efficiency and hatching rate in the hatcheries of rainbow trout