Identification of Novel Genes Associated with Fish Skeletal Muscle Adaptation during Fasting and Refeeding Based on a Meta-Analysis.

The regulation of the fish phenotype and muscle growth is influenced by fasting and refeeding periods, which occur in nature and are commonly applied in fish farming. However, the regulators associated with the muscle responses to these manipulations of food availability have not been fully characterized. We aimed to identify novel genes associated with fish skeletal muscle adaptation during fasting and refeeding based on a meta-analysis. Genes related to translational and proliferative machinery were investigated in pacus (Piaractus mesopotamicus) subjected to fasting (four and fifteen days) and refeeding (six hours, three and fifteen days). Our results showed that different fasting and refeeding periods modulate the expression of the genes mtor, rps27a, eef1a2, and cdkn1a. These alterations can indicate the possible protection of the muscle phenotype, in addition to adaptive responses that prioritize energy and substrate savings over cell division, a process regulated by ccnd1. Our study reveals the potential of meta-analysis for the identification of muscle growth regulators and provides new information on muscle responses to fasting and refeeding in fish that are of economic importance to aquaculture.

Quality assessment of amazonian fish from fish farming stored on ice / Avaliação da qualidade de pescados amazônicos provenientes de piscicultura armazenados em gelo

The cultivation of natives Amazonian fish such as tambaqui (Colossoma macropomum), pirapitinga (Piaractus brachypomus), tambatinga (female, Colossoma macropomum X Piaractus brachypomus, male) and Pintando da Amazônia (female, Pseudoplatystoma sp. X Leiarius marmoratus, male) temmoratus, increased in recent years, making studies related to the validity of these foods after processing necessary. Therefore, the aimed of the study was to evaluate the sensory, microbiological (Staphylococcus coagulase positive count and presence of Salmonella spp.) and chemical (pH and Total Volatile Bases (TVB) quality of fresh gutted fish stored on ice. Nine specimens of each species were used, all cultivated in an excavated tanks. The fasting time ranged from 16 to 48 hours, depending on the species, the fish was slaughtered by means of cold shock. The fish was gutted and stored in the fish fridge. Sensory analysis was performed by a trained team available. For other analyses, it was sent to a laboratory specializing in food analysis. The sensory analysis of fresh eviscerated tambaqui was characteristic of the species until the 15th day of storage. Fresh eviscerated pirapitinga presented until the 16th day. The fresh eviscerated tambatinga hybrid was kept until the 14th day of storage. And for the Pintado da Amazônia, the organoleptic characteristics were presentable until the 12th day of storage. The microbiological and physical-chemical analyzes were in accordance with Brazilian legislation in all specimens of the analyzed species. It was observed that the longer the fasting period, there was a numerical increase in the pH of the fish meat.(AU)

O cultivo de peixes nativos da Amazônia como tambaqui (Colossoma macropomum), pirapitinga (Piaractus brachypomus), tambatinga (fêmea, Colossoma macropomum X Piaractus brachypomus, macho) e o pintado da Amazônia (fêmea, Pseudoplatystoma sp. X Leiarius marmoratus, macho) tem aumentado nos últimos anos, fazendo com que estudos relacionados a validade desses alimentos após o processamento sejam necessários. Por isso, o objetivo do estudo foi avaliar os parâmetros de qualidade senso-rial, microbiológica (contagem de Staphylococcus coagulase positiva e presença de Salmonella spp.) e química (pH e Bases Voláteis Totais (BVT)) deses pescados eviscerados frescos armazenados em gelo. Foram utilizados 9 exemplares de cada espécie, todos de origem de cultivo em viveiro escavado. O tempo de jejum variou de 16 a 48 horas, dependendo da espécie, o abate do pescado foi por meio de choque térmico. O pescado foi eviscerado e armazenado no frigorifico de pescado. Analise sensorial foi realizada por uma equipe treinada disponível. Para as demais análises foi enviado para um laboratório especializado em análises de alimentos. A análise sensorial do tambaqui eviscerado fresco estava característica da espécie até o 15°dia de estocagem. A pirapitinga evisce-rado fresco apresentou até o 16°dia. O hibrido tambatinga eviscerado fresco foi até o 14°dia de estocagem. E para o pintado da Amazônia as características organolépticas estavam apresentáveis até o dia 12° dia de armazenamento. As analises microbiológicas e físico químicas estavam de acordo com a legislação brasileira em todos os exemplares das espécies analisadas. Foi observado que quanto maior o tempo de jejum, houve um aumento numérico no pH da carne dos pescados.(AU)

Effect of Lippia grata essential oil as a feed additive on the performance of tambatinga juveniles / Efeito do óleo essencial de Lippia grata como aditivo alimentar sobre o desempenho de juvenis de tambatinga

Lippia grata (formerly known as Lippia gracillis) is an aromatic plant native to Brazil, with leaves rich in essential oils that possess significant biological activities. We evaluated the effect of essential oil of L. grata (EOLG) as a dietary additive on the growth, somatic indices, and biochemical parameters of juveniles (5.25 ± 0.26 g) of tambatinga, a hybrid fish obtained by crossing tambaqui (Colossoma macropomum) with pirapitinga (Piaractus brachypomum) of great economic importance in north and northeastern Brazil. We evaluated four dietary treatments, consisting of EOLG supplemented at 0.0, 0.5, 1.0, and 2.0 mL kg-1, over 60 days. Carcass yield was significantly higher in fish fed all EOLG diets compared to those fed the control diet (0.0 mL kg-1). Animals that received the 0.5 mL kg-1 treatment gained significantly more weight and showed a higher specific growth rate than those treated with 1.0 and 2.0 ml kg-1 EOLG, although none differed significantly from the control. The feed conversion rate was significantly lower in the 0.5 than in the 1.0 mL kg-1 treatment. Compared with higher concentrations, the diet containing 0.5 mL kg-1 EOLG increased the use of muscle glycogen, glucose, and lactate to meet energy demands, avoiding the use of muscle protein. Our results suggest that dietary supplementation with EOLG significantly improves carcass yield in tambatinga juveniles but that concentrations above 0.5 mL kg-1 may compromise growth rates and carbohydrate metabolism in this fish.(AU)

Lippia grata (previamente conhecida como Lippia gracillis) é uma planta aromática nativa do Brasil, com folhas ricas em óleos essenciais que possuem atividades biológicas significativas. Avaliamos o efeito do óleo essencial de L. grata (OELG) como aditivo alimentar sobre o crescimento, índices somáticos e parâmetros bioquímicos de juvenis (5,25 ± 0,26 g) de tambatinga, um hibrido obtido do cruzamento de tambaqui (Colossoma macropomum) com pirapitinga (Piaractus brachypomum) com grande importância econômica no norte e nordeste do Brazil. Foram avaliados quatro tratamentos dietéticos consistindo na suplementação com OELG em 0,0; 0,5; 1,0 e 2,0 mL kg-1 durante 60 dias. O rendimento de carcaça foi significativamente maior nos peixes alimentados com todas as dietas contendo OELG em comparação à dieta controle. Os animais do tratamento 0,5 mL kg-1 ganharam significativamente mais peso e apresentaram maior taxa de crescimento específico do que aqueles tratados com 1,0 e 2,0 mL kg-1 OELG, embora nenhum tenha diferido significativamente do controle. A taxa de conversão alimentar foi significativamente menor no tratamento 0,5 mL kg-1 do que no tratamento 1,0 mL kg-1. Comparada com as concentrações mais altas, a dieta contendo 0,5 mL kg-1 OELG aumentou o uso de glicogênio muscular, glicose e lactato para suprir as demandas energéticas, evitando o uso de proteína muscular. Nossos resultados sugerem que a suplementação dietética com OELG melhora significativamente o rendimento de carcaça de juvenis de tambatinga, mas concentrações acima de 0,5 mL kg-1 podem comprometer as taxas de crescimento e metabolismo de carboidratos desses peixes.(AU)

A typical enzyme activity for glutathione conjugation indicates exposure of pacu to pollutants

Functional enzyme assays to detect sublethal poisoning of Neotropical fish are paramount. Accordingly, we assayed a glutathione S-transferase (GST) activity in liver and kidney cytosols from Piaractus mesopotamicus injected with methyl parathion or benzo[a]pyrene using the substrate 1-chloro-2,4-dinitrobenzene (CDNB), which is the usual substrate for assaying a known general activity of GST. Since the most reactive substrate is required to reveal specific changes in enzyme activity, we also used two alternative substrates, 1,2-dichloro-4-nitrobenzene (DCNB) and ethacrynic acid (ETHA). Activities with CDNB or ETHA did not change. However, assays with DCNB showed that methyl parathion caused a decrease in GST activity in the liver on the 24th, 48th and 96th hour after the injection. DCNB also revealed that GST activity in the liver increased seven days after benzo[a]pyrene injection, coming down to normal after fourteen days. Benzo[a]pyrene, but not methyl parathion, increased the activities with DCNB in cytosol from the kidney seven and fourteen days after the injection. Thus, a decreased liver GST activity assayed with DCNB corresponded to contamination of P. mesopotamicus with methyl parathion. The increase of this GST activity in the liver and the kidney correlates to pacu contamination with polycyclic aromatic hydrocarbons.

Ensaios práticos de enzimas para detectar contaminação subletal de peixes neotropicais são da maior importância. Assim, ensaiamos a atividade da glutationa S-transferase (GST) em citosóis de fígado e de rim de Piaractus mesopotamicus injetados com metilparation ou benzo[a]pireno usando 1-cloro-2,4-dinitrobenzeno (CDNB), o substrato usual para ensaiar uma denominada atividade geral de GST. Desde que para indicar alterações na atividade de uma isoenzima, é necessário o substrato mais reativo, também usamos dois substratos alternativos, o 1,2-dicloro-4-nitrobenzeno (DCNB) e o ácido etacrínico (ETHA). As atividades com CDNB ou ETHA não mudaram. Entretanto, ensaios com DCNB mostraram que metilparation decresceu a atividade de GST no fígado em 24, 48 e 96 horas depois da injeção. O DCNB também revelou que sete dias depois da injeção de benzo[a]pireno a atividade da GST aumentou no fígado, normalizando depois de 14 dias. Benzo[a]pireno, mas não metilparation, aumentou as atividades com DCNB no citosol dos rins sete e 14 dias depois da injeção. Assim, uma atividade de GST ensaiada com DCNB diminuída no fígado correspondeu à contaminação de P. mesopotamicus com metilparation. O aumento dessa atividade de GST no fígado e nos rins está correlacionada com contaminação do pacu por hidrocarbonetos policíclicos aromáticos.

Pantanal's fish native meatballs has the nutritional values increased with the use of pequi in its recipe

The study aimed to evaluate whether the addition of pequi increases the nutritional value of meatballs made with piranha and pacu fillets. Piranhas were obtained from the colony of fishermen; pacu with the fish farmer and the pequis were collected in nature. Fish were filleted and triturated, and the resulting masses were used to prepare 4 types of meatballs: piranha fillet with 2.0% pequi pulp, piranha fillet without pequi pulp, pacu fillet with with 2.0% pequi pulp, and pacu fillet without pequi pulp. After preparation, acceptance, purchase intention and frequency of consumption were evaluated with untrained tasters. Chemical composition parameters evaluated were crude protein, lipids, ash, moisture, carotenoids and antioxidant activity. Results of acceptability for all formulations were similar. The chemical composition of piranha meatballs presented differences (p < 0.05) for lipids and carotenoids. Pacu meatballs showed no difference (p > 0.05) for moisture, carotenoids, and antioxidant activity. The addition of pequi did not alter the organoleptic characteristics, however increased the nutritional values, therefore, it can add value to the product to be marketed and be more nutritionally attractive to the consumer.(AU)

Pantanals fish native meatballs has the nutritional values increased with the use of pequi in its recipe

The s tudy aimed to evaluate whether the addition of pequi increases the nutritional v alue of meatballs made with piranha and pacu fillets. Piranhas were obtained fro m the colony of fishermen; pacu with the fish farmer and the pequis were collected in nature. Fish were filleted and triturated, and the result ing masses were used to prepare 4 types of meatballs: piranha fillet with 2.0% pequi pulp, piranha fillet without pequi pulp, pacu fillet with w ith 2.0% pequi pulp, and pacu fillet without pequipulp. After preparation, accep tance, purchase intention and frequency of consumption were evaluated with untra ined tasters. Chemical composition parameters evaluated were crude protein, lipi ds, ash, moisture, carotenoids and antioxidant activity. Results of acce ptability for all formulations were similar. The chemical composit ion of piranha meatballs presented differences (p<0.05) for lipids and carotenoi ds. Pacu meatballs showed no difference (p>0.05) for moisture, carotenoids,and a ntioxidant activity. The addition of pequi did not alter the organoleptic c haracteristics, however increased the nutritional values, therefore, it can add value to the product to be marketed and be more nutritionally attractive to the consumer.(AU)

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.

Uso de perifiton en un sistema de policultivo en agro acuicultura integrada en la comunidad indígena de Jimaín, Sierra Nevada de Santa Marta (Colombia) / Periphyton-based polyculture in an integrated agri-aquaculture system at the indigenous community of Jimaín, Sierra Nevada de Santa Marta (Colombia)

RESUMEN Los Sistemas de Agro Acuicultura Integrada (SAAI) han sido estudiados como opción para la producción de pescado en comunidades con recursos limitados. Así mismo, el uso de perifiton se ha convertido recientemente en una alternativa viable por el aporte de alimento natural de bajo costo. El objetivo de este estudio fue evaluar el efecto del perifiton sobre el desempeño productivo del policultivo Piaractus sp. (cachama híbrida) y Prochilodus magdalenae (bocachico) en SAAI en la comunidad Indígena de Jimaín, Colombia. Se sembraron 1,5 alevinos de cachama híbrida y 1,5 bocachicos/m2, con peso promedio de 0,49 ± 0,14 g y 1,83 ±1,61 g respectivamente, en seis estaques en tierra de 90 m2 tres de los cuales contaron con varas de madera (3 varas/m2) para la fijación de perifiton. La duración del cultivo fue de 135 días. Los tratamientos (CS: con sustrato y SS: sin sustratos) recibieron una dieta suplementaria dos veces al día, calculada como porcentaje de la biomasa con ajuste quincenal. Se realizaron biometrías quincenales. Los datos productivos por especie y para el policultivo se evaluaron mediante ANOVA con un modelo lineal general (p < 0,05). Los datos de peso (g) y longitud estándar (cm) por especie se evaluaron mediante un modelo mixto de medidas repetidas. No se encontraron efectos del sustrato sobre los parámetros productivos analizados tanto para cada especie, como para el policultivo. Se presentó interacción significativa para el peso del bocachico el día 90 (CS: 74,7 y SS: 47,1). Según los resultados obtenidos, la utilización de perifiton y el manejo en policultivo de especies nativas requiere más estudios.

ABSTRACT Integrated agri-aquaculture systems (IAAS) have been studied as an option for fish production in communities with limited resources. Likewise, the use of periphyton has recently become a viable alternative for its contribution of low-cost natural food. The effect of periphyton use on the productive yield of a hybrid cachama and bocachico polyculture in IAAS, was studied in the Jimaín Indigenous community, Colombia. For this experiment, 1.5 hybrid cachama and 1.5 bocachico fingerlings/m2 were stocked with average weights of 0.49 ± 0.14 g and 1.83 ± 1.61 g, respectively, in six 90 m2 land ponds; three of these ponds had wooden dowels (three dowels/m2) for periphyton fixation. The growth evaluation lasted 135 days. The treatments (WS: with substrate and WOS: without substrates) received a supplementary diet, adjusted as a percentage of the biomass with biweekly adjustment, twice a day. Biometrics were performed every two weeks. The productive data by species and for the polyculture were evaluated using an ANOVA with a general linear model (p <0.05). Weight (g) and standard length (cm) data by species were evaluated using a mixed model of repeated measures. No substrate effects were found on the productive parameters analyzed for each species as well as for the polyculture. A significant interaction was observed for bocachico weight on day 90 (WS: 74.7 and WOS: 47.1). According to the obtained results, optimizing the use of periphyton and the management of native species polyculture requires further studies.

Using aerobic exercise to evaluate sub-lethal tolerance of acute warming in fishes.

We investigated whether fatigue from sustained aerobic swimming provides a sub-lethal endpoint to define tolerance of acute warming in fishes, as an alternative to loss of equilibrium (LOE) during a critical thermal maximum (CTmax) protocol. Two species were studied, Nile tilapia (Oreochromis niloticus) and pacu (Piaractus mesopotamicus). Each fish underwent an incremental swim test to determine gait transition speed (UGT), where it first engaged the unsteady anaerobic swimming mode that preceded fatigue. After suitable recovery, each fish was exercised at 85% of their own UGT and warmed 1°C every 30 min, to identify the temperature at which they fatigued, denoted as CTswim Fish were also submitted to a standard CTmax, warming at the same rate as CTswim, under static conditions until LOE. All individuals fatigued in CTswim, at a mean temperature approximately 2°C lower than their CTmax Therefore, if exposed to acute warming in the wild, the ability to perform aerobic metabolic work would be constrained at temperatures significantly below those that directly threatened survival. The collapse in performance at CTswim was preceded by a gait transition qualitatively indistinguishable from that during the incremental swim test. This suggests that fatigue in CTswim was linked to an inability to meet the tissue oxygen demands of exercise plus warming. This is consistent with the oxygen and capacity limited thermal tolerance (OCLTT) hypothesis, regarding the mechanism underlying tolerance of warming in fishes. Overall, fatigue at CTswim provides an ecologically relevant sub-lethal threshold that is more sensitive to extreme events than LOE at CTmax.

Novel myxosporean species parasitizing an economically important fish from the Amazon basin.

This paper provides morphological and phylogenetic analyses of two new myxobolid species found infecting Piaractus brachypomus from the Amazon basin. The fish were caught in the Tapajós River, in the municipality of Santarém, in the state of Pará, Brazil. The plasmodial development of Henneguya brachypomus n. sp. occurred in the gill lamellae while Myxobolus pirapitingae n. sp. developed in the pyloric cecum. Morphological analyses did not identify inflammatory infiltrate for either species, but H. brachypomus n. sp. induced stretching of the epithelium, compression of the adjacent tissues, and displacement and deformation of the neighboring lamellae. The mature myxospores of H. brachypomus n. sp. were ellipsoid, with a length of 11.7-13.8 µm, a width of 4.0-4.6 µm, and a thickness of 3.5-4.3 µm. The polar capsules were elongated, with a length of 5.6-7.3 µm and a width of 1.3-2.0 µm, and each contained a polar filament with 8-9 coils. The caudal process was 40.5-48.1 µm long and the total length of the myxospore was 52.4-61.6 µm. Myxobolus pirapitingae n. sp. exhibited rounded mature myxospores measuring 10.0-11.1 µm in length, 7.0-7.6 µm in width, and 5.4-6.3 µm in thickness. The polar capsules were of equal size and occupied less than half the myxospore, measuring 3.5-4.0 µm in length and 2.0-2.6 µm in width, with each containing a polar filament with 6-7 coils. Phylogenetic analysis based on partial small subunit ribosomal DNA (ssrDNA) sequences showed that H. brachypomus n. sp. clustered as a sister species of Henneguya piaractus, while M. pirapitingae n. sp. was grouped in a sub-clade together with Myxobolus matosi and Myxobolus colossomatis.

ß-Glucan enhances respiratory activity of leukocytes suppressed by stress and modulates blood glucose levels in pacu (Piaractus mesopotamicus).

We evaluated the immune response of pacu fed with a ß-glucan diet (0.5%) for 10 days. After the feeding period, fish were subjected to handling and 3 h after, inoculated with Aeromonas hydrophila. Fish were sampled before handling (baseline condition), 3, 6, and 24 h and 1 week after inoculation. A higher level of blood glucose was found in fish treated with ß-glucan in baseline conditions. Handling and bacterial inoculation increased the circulating levels of cortisol and glucose and promoted the acute inflammatory response (lymphopenia and neutrophilia). ß-Glucan prevented the decrease in the respiratory activity of leukocytes observed in the control group at 3 h sampling. ß-Glucan did not affect the complement and lysozyme, which were activated 24 h after the bacterial challenge in control fish. A reduction in the number of leukocytes was found in fish treated with ß-glucan 1 week after the challenge. We suggest two plausible hypotheses for this event: (1) it could be attributed to a depletion of the immune responses or (2) it could be due to a mobilization of the leukocytes to the spleen for antigen presenting/processing. In general, ß-glucan avoided the reduction of the activity of leukocytes after stress and the bacterial challenge and increased the baseline glucose levels. Our findings confirm the immunomodulatory action of glucan and add evidence showing that glucan can have a role in stress response.

Growth curve of pacu and the patinga hybrid farmed in a semi-intensive system / Curva de crescimento do pacu e do híbrido patinga produzidos em sistema semi-intensivo

The growth curve is a tool that can be used to determine the performance potential of fish at different ages. The aim of this study was to evaluate the growth curve of pacu (P. mesopotamicus) and the patinga hybrid (P. mesopotamicus × P. brachypomus) cultivated in a semi-intensive system. In the initial phase of the experiment, the pacu and patinga fish weighed 32.6 ± 7.5 g and 24.9 ± 7.1 g, respectively. The Gompertz model was adopted to describe the growth curve. At the end of the experiment, body weight, standard length, head length, body height and body width did not differ significantly between the pacu (625.9 g; 25.6 cm; 7.2 cm; 12.1 cm; 4.5 cm) and the patinga hybrid (727.1 g; 27.3 cm; 7.6 cm; 13.2 cm; 4.9 cm). The asymptotic value (parameter A), relative growth rate (parameter B), and age at the inflection point (parameter C) of the growth curve of the two species were similar for weight and for the evaluated morphometric traits. The asymptotic values obtained for weight in the pacu and the patinga hybrid were 1212.0 g and 1348.0 g, respectively. The growth curve of the patinga hybrid is similar to that of pacu, contrasting with the belief of many fish farmers.(AU)

A curva de crescimento possibilita determinar o potencial de desempenho dos peixes em diferentes idades. O objetivo do estudo foi avaliar a curva de crescimento do pacu (P. mesopotamicus) e do híbrido patinga (P. mesopotamicus x P. brachypomus) produzidos em sistema semi-intensivo. Foram utilizados no início do experimento pacu e patinga com peso de 32,6 ± 7,5 g e 24,9 ± 7,1 g, respectivamente. Foi utilizado o modelo Gompertz para descrever a curva de crescimento. No final do experimento, o peso corporal, comprimento padrão, comprimento da cabeça, altura do corpo e largura do corpo não diferiram significativamente entre o pacu (625,9 g; 25,6 cm; 7,2 cm; 12,1 cm; 4,5 cm) e o híbrido patinga (727,1g; 27,3 cm; 7,6 cm; 13,2 cm; 4,9 cm). O valor assintótico (parâmetro A), taxa de crescimento relativo (parâmetro B) e idade no ponto de inflexão (parâmetro C) da curva de crescimento do pacu e patinga foram semelhantes para peso e características morfométricas avaliadas. O valor assintótico obtido para peso no pacu e no híbrido patinga foi de 1212,0 g e 1348,0 g, respectivamente. O híbrido patinga apresenta curva de crescimento semelhante ao pacu, contrastando com a crença de muitos piscicultores.(AU)

Growth curve of pacu and the patinga hybrid farmed in a semi-intensive system / Curva de crescimento do pacu e do híbrido patinga produzidos em sistema semi-intensivo

The growth curve is a tool that can be used to determine the performance potential of fish at different ages. The aim of this study was to evaluate the growth curve of pacu (P. mesopotamicus) and the patinga hybrid (P. mesopotamicus × P. brachypomus) cultivated in a semi-intensive system. In the initial phase of the experiment, the pacu and patinga fish weighed 32.6 ± 7.5 g and 24.9 ± 7.1 g, respectively. The Gompertz model was adopted to describe the growth curve. At the end of the experiment, body weight, standard length, head length, body height and body width did not differ significantly between the pacu (625.9 g; 25.6 cm; 7.2 cm; 12.1 cm; 4.5 cm) and the patinga hybrid (727.1 g; 27.3 cm; 7.6 cm; 13.2 cm; 4.9 cm). The asymptotic value (parameter A), relative growth rate (parameter B), and age at the inflection point (parameter C) of the growth curve of the two species were similar for weight and for the evaluated morphometric traits. The asymptotic values obtained for weight in the pacu and the patinga hybrid were 1212.0 g and 1348.0 g, respectively. The growth curve of the patinga hybrid is similar to that of pacu, contrasting with the belief of many fish farmers.

A curva de crescimento possibilita determinar o potencial de desempenho dos peixes em diferentes idades. O objetivo do estudo foi avaliar a curva de crescimento do pacu (P. mesopotamicus) e do híbrido patinga (P. mesopotamicus x P. brachypomus) produzidos em sistema semi-intensivo. Foram utilizados no início do experimento pacu e patinga com peso de 32,6 ± 7,5 g e 24,9 ± 7,1 g, respectivamente. Foi utilizado o modelo Gompertz para descrever a curva de crescimento. No final do experimento, o peso corporal, comprimento padrão, comprimento da cabeça, altura do corpo e largura do corpo não diferiram significativamente entre o pacu (625,9 g; 25,6 cm; 7,2 cm; 12,1 cm; 4,5 cm) e o híbrido patinga (727,1g; 27,3 cm; 7,6 cm; 13,2 cm; 4,9 cm). O valor assintótico (parâmetro A), taxa de crescimento relativo (parâmetro B) e idade no ponto de inflexão (parâmetro C) da curva de crescimento do pacu e patinga foram semelhantes para peso e características morfométricas avaliadas. O valor assintótico obtido para peso no pacu e no híbrido patinga foi de 1212,0 g e 1348,0 g, respectivamente. O híbrido patinga apresenta curva de crescimento semelhante ao pacu, contrastando com a crença de muitos piscicultores.

Genetic diversity of migratory fish populations of the Rio Grande Reservoir (São Paulo, Brazil) / Diversidade genética de populações de peixes migratórios do reservatório do Rio Grande (São Paulo, Brasil)

In recent years, anthropogenic factors such as pollution, overfishing, and construction of hydroelectric plants have significantly impacted natural fish populations. Research focusing on genetically evaluation of these impacts is necessary to objectively target conservation programs. The aim of this study was to evaluate the genetic diversity of Curimba (Prochilodus lineatus), Pacu (Piaractus mesopotamicus), and Piracanjuba (Brycon orbignyanus) populations from the Água Vermelha Reservoir, Rio Grande-SP. Microsatellite loci were amplified, producing 56, 24, and 26 alleles for the populations of the three species, respectively. The number of alleles per locus ranged from three to ten for P. lineatus, two to five for P. mesopotamicus, and two to four for B. orbignyanus. The observed heterozygosity (Ho) was higher in the P. lineatus population (0.547), relative to the P. mesopotamicus and B. orbignyanus populations (0.473 and 0.527, respectively). The mean values of Ho were lower than the average expected heterozygosity (He) in the three species, being corroborated by the positive inbreeding coefficient (Fis). Deviations from the Hardy-Weinberg equilibrium (HWE) were found in five, three, and two loci for P. lineatus, P. mesopotamicus, and B. orbignyanus, respectively. Wilcoxon tests revealed recent bottlenecks in the three species, evidenced by a significant excess of heterozygotes (p < 0.05) detected only in the Infinite Allele Model (IAM). In conclusion, adequate genetic variability was observed in the three populations with the presence of heterozygous deficits.(AU)

Nos últimos anos, fatores antrópicos como poluição, sobrepesca e construção de hidrelétricas têm impactado significativamente as populações naturais de peixes. Pesquisas que permitam avaliar geneticamente esse impacto são necessárias para orientar objetivamente programas de conservação. O objetivo do presente estudo foi avaliar a diversidade genética de populações de Curimba (Prochilodus lineatus), Pacu (Piaractus mesopotamicus) e Piracanjuba (Brycon orbignyanus) provenientes do reservatório de Água Vermelha, Rio Grande-SP. Foram amplificados loci microssatélites que produziram 56, 24 e 26 alelos para as populações das três espécies, respectivamente. O número de alelos por locus variou de três a dez para P. lineatus, dois a cinco para P. mesopotamicus e dois a quatro para B. orbignianus. A heterozigosidade observada (Ho) foi mais elevada na população de P. lineatus (0,547) em relação às populações de P. mesopotamicus e B. orbignyanus (0,473 e 0,527, respectivamente). A média dos valores de Ho foram inferiores à média de He nas três espécies sendo corroborado pelo Fis positivo observado. Foi encontrado desvio do equilíbrio de Hardy-Weinberg (HWE) em cinco loci para P. lineatus, três loci para P. mesopotamicus e dois em B. orbignyanus. A análise de bottleneck revelou excesso de heterozigotos (p<0,05) pelo teste de Wilcoxon nas três espécies apenas no modelo Infinite Allele Model (IAM). Foi observada adequada variabilidade genética nas três populações com a presença de déficit de heterozigotos.(AU)

Viscera of fishes as raw material for extraction of glycosaminoglycans of pharmacological interest.

World fisheries and aquaculture production totaled 167 million tons in 2014. This high fish production generates a lot of waste that could be used as raw material for extraction of substances of pharmacological interest. In this work, we extract and characterize glycosaminoglycans (GAGs) present in the viscera of Nile tilapia (Oreochromis niloticus) and Pacu (Piaractus mesopotamicus), which are among the most vastly produced fishes in inland aquaculture in Brazil. Moreover, the anticoagulant activity of the GAGs fractions was evaluated. GAGs were obtained from total defatted viscera, after proteolysis, precipitation with ethanol, anion exchange chromatography and treatment with chondroitinase. Chondroitin sulfate (CS), dermatan sulfate (DS) and heparan sulfate (HS) were identified by agarose gel electrophoresis and NMR analyses. CS, DS and HS were identified in equivalent fractions obtained from both fishes, and all GAGs fractions showed anticoagulant activity.

Hematological parameters of the hybrid serrasalmids farmed in Central-Western Brazil / Parâmetros hematológicos de serrasalmídeos híbridos cultivados na região Centro-Oeste do Brasil

This study evaluated the hematological parameters of tambacu and patinga, two the hybrid serrasalmid fishes farmed in the state of Mato Grosso do Sul, Brazil, with emphasis on the influence of seasons on them. Two-hundred forty hybrid fishes, 120 tambacus and 120 patingas, were collected over 12 months to assess their hematological parameters and compare them between the warm (October-March) and cold seasons (April-September). Water quality parameters were also measured weekly to test for the influence of environmental conditions on the results. The dissolved oxygen content in the water decreased in the warm season, and increased in the cold season. In the warm season, tambacus presented significantly higher values (p<0.05) of the total plasmatic protein (TPP), hemoglobin, mean corpuscular volume (MCV), mean corpuscular hemoglobin concentration (MCHC), and eosinophil count parameters. In the cold season, counts of erythrocytes, thrombocytes, total leukocytes, lymphocytes, and neutrophils were higher in tambacus (p<0.05). For patinga, MCV was higher in the warm season, while hemoglobin, erythrocytes, MCHC, total leukocytes, and basophil counts were higher (p<0.05) in the cold season. These results demonstrated the influences of seasonality on the hematological parameters of the hybrids tambacu and patinga when held under normal farming conditions in the region.(AU)

Este estudo avaliou os parâmetros hematológicos de híbridos tambacu e patinga cultivados no Mato Grosso do Sul, Brasil, com ênfase na influência das épocas do ano. Duzentos e quarenta peixes híbridos, 120 tambacus e 120 patingas, foram coletados ao longo de 12 meses para análises hematológicas, comparando a estação quente (Outubro-Março) com a estação fria (Abril-Setembro). Os parâmetros de qualidade de água foram medidos semanalmente, para verificar sua influência sobre os parâmetros hematológicos. A estação quente mostrou tendência ao declínio nos níveis de oxigênio dissolvido, enquanto na estação fria ocorreu o inverso. Na estação quente, tambacus apresentaram valores mais altos (p<0,05) de proteína plasmática total (TPP), concentração de hemoglobina, volume corpuscular médio (MCV), concentração de hemoglobina corpuscular média (MCHC) e número de eosinófilos. Na estação fria, as contagens de eritrócitos, trombócitos, leucócitos totais, linfócitos e neutrófilos foram mais altas (p<0,05). Em patingas, valores mais altos de MCV foram observados na estação quente, enquanto a concentração de hemoglobina, eritrócitos, MCHC, leucócitos totais e basófilos foram mais altos (p<0,05) na estação fria. Os resultados mostram influência da sazonalidade sobre os parâmetros hematológicos dos híbridos tambacu e patinga mantidos em condições típicas de cultivo na região.(AU)

Growth performance and incidence of skeletal anomalies in pacu larvae under different weaning protocols / Desempenho e incidência de anomalias esqueléticas em larvas de pacu sob diferentes protocolos de transição alimentar

The inadequate supply of food during a fishs larval stage, in addition to impairing growth and survival, may lead to the emergence of skeletal anomalies, since essential nutrients are involved in the osteogenic process. The aim of this study was to evaluate the effects of two weaning periods on growth, survival and incidence of skeletal anomalies in pacu larvae (Piaractus mesopotamicus) during its initial development. The larvae (5 dph) were placed in 100L tanks at a density of 12 larvae L-1, during 42 days. The experiment was conducted in a completely randomized design with four feeding treatments: (A) larvae fed only Artemia nauplii; (D) larvae fed only formulated diet; and two treatments with different weaning periods, early at six (W6) and late, at twelve days of feeding (W12). Higher growth indexes and survival rates were observed in A and W12, in comparison to W6 and D. At the end of the experiment, larvae fed Artemia nauplii and subjected to late weaning (W12) presented higher mass gain and survival, in comparison to W6 and D, however the incidence of skeletal anomalies was similar among treatments. It was concluded that the emergence of skeletal anomalies in P. mesopotamicus larvae was not associated to the weaning protocols used in this study and late weaning, at 12 days of feeding, did not impair growth and survival of these larvae.(AU)

A oferta inadequada do alimento durante a fase larval dos peixes, além de prejudicar o crescimento e a sobrevivência, podem causar anomalias esqueléticas, uma vez que nutrientes essenciais estão envolvidos na osteogênese. O objetivo deste estudo foi avaliar os efeitos de dois períodos de transição alimentar no crescimento, sobrevivência e na incidência de anomalias esqueléticas em larvas de pacu (Piaractus mesopotamicus) durante seu desenvolvimento inicial. Larvas com 5 dias pós-eclosão (dph) foram acondicionadas em tanques (100L), em uma densidade de 12 larvas L-1, durante 42 dias. O experimento foi conduzido em delineamento inteiramente casualizado e apresentou quatro tratamentos alimentares: (A) larvas alimentadas apenas com náuplios de artêmia; (D) larvas alimentadas apenas com dieta formulada; e dois tratamentos com diferentes períodos de início da transição entre alimento vivo e formulado, (W6) prematuro, aos seis dias de alimentação, e (W12) tardio, aos 12 dias de alimentação. Ao final do experimento, as larvas dos tratamentos A e W12 apresentaram médias de ganho em massa e sobrevivência maiores que as dos tratamentos W6 e D, no entanto a incidência de anomalias esqueléticas foi similar entre os tratamentos. Foi possível concluir que incidência de anomalias esqueléticas em larvas de P. mesopotamicus não foi associada aos protocolos de transição alimentar adotados nesse estudo e a transição alimentar tardia, aos 12 dias de alimentação, pode ser realizada sem comprometer o crescimento e sobrevivência das larvas.(AU)

Growth performance and incidence of skeletal anomalies in pacu larvae under different weaning protocols / Desempenho e incidência de anomalias esqueléticas em larvas de pacu sob diferentes protocolos de transição alimentar

The inadequate supply of food during a fish’s larval stage, in addition to impairing growth and survival, may lead to the emergence of skeletal anomalies, since essential nutrients are involved in the osteogenic process. The aim of this study was to evaluate the effects of two weaning periods on growth, survival and incidence of skeletal anomalies in pacu larvae (Piaractus mesopotamicus) during its initial development. The larvae (5 dph) were placed in 100L tanks at a density of 12 larvae L-1, during 42 days. The experiment was conducted in a completely randomized design with four feeding treatments: (A) larvae fed only Artemia nauplii; (D) larvae fed only formulated diet; and two treatments with different weaning periods, early at six (W6) and late, at twelve days of feeding (W12). Higher growth indexes and survival rates were observed in A and W12, in comparison to W6 and D. At the end of the experiment, larvae fed Artemia nauplii and subjected to late weaning (W12) presented higher mass gain and survival, in comparison to W6 and D, however the incidence of skeletal anomalies was similar among treatments. It was concluded that the emergence of skeletal anomalies in P. mesopotamicus larvae was not associated to the weaning protocols used in this study and late weaning, at 12 days of feeding, did not impair growth and survival of these larvae.

A oferta inadequada do alimento durante a fase larval dos peixes, além de prejudicar o crescimento e a sobrevivência, podem causar anomalias esqueléticas, uma vez que nutrientes essenciais estão envolvidos na osteogênese. O objetivo deste estudo foi avaliar os efeitos de dois períodos de transição alimentar no crescimento, sobrevivência e na incidência de anomalias esqueléticas em larvas de pacu (Piaractus mesopotamicus) durante seu desenvolvimento inicial. Larvas com 5 dias pós-eclosão (dph) foram acondicionadas em tanques (100L), em uma densidade de 12 larvas L-1, durante 42 dias. O experimento foi conduzido em delineamento inteiramente casualizado e apresentou quatro tratamentos alimentares: (A) larvas alimentadas apenas com náuplios de artêmia; (D) larvas alimentadas apenas com dieta formulada; e dois tratamentos com diferentes períodos de início da transição entre alimento vivo e formulado, (W6) prematuro, aos seis dias de alimentação, e (W12) tardio, aos 12 dias de alimentação. Ao final do experimento, as larvas dos tratamentos A e W12 apresentaram médias de ganho em massa e sobrevivência maiores que as dos tratamentos W6 e D, no entanto a incidência de anomalias esqueléticas foi similar entre os tratamentos. Foi possível concluir que incidência de anomalias esqueléticas em larvas de P. mesopotamicus não foi associada aos protocolos de transição alimentar adotados nesse estudo e a transição alimentar tardia, aos 12 dias de alimentação, pode ser realizada sem comprometer o crescimento e sobrevivência das larvas.

Hematological parameters of the hybrid serrasalmids farmed in Central-Western Brazil / Parâmetros hematológicos de serrasalmídeos híbridos cultivados na região Centro-Oeste do Brasil

This study evaluated the hematological parameters of tambacu and patinga, two the hybrid serrasalmid fishes farmed in the state of Mato Grosso do Sul, Brazil, with emphasis on the influence of seasons on them. Two-hundred forty hybrid fishes, 120 tambacus and 120 patingas, were collected over 12 months to assess their hematological parameters and compare them between the warm (October-March) and cold seasons (April-September). Water quality parameters were also measured weekly to test for the influence of environmental conditions on the results. The dissolved oxygen content in the water decreased in the warm season, and increased in the cold season. In the warm season, tambacus presented significantly higher values (p<0.05) of the total plasmatic protein (TPP), hemoglobin, mean corpuscular volume (MCV), mean corpuscular hemoglobin concentration (MCHC), and eosinophil count parameters. In the cold season, counts of erythrocytes, thrombocytes, total leukocytes, lymphocytes, and neutrophils were higher in tambacus (p<0.05). For patinga, MCV was higher in the warm season, while hemoglobin, erythrocytes, MCHC, total leukocytes, and basophil counts were higher (p<0.05) in the cold season. These results demonstrated the influences of seasonality on the hematological parameters of the hybrids tambacu and patinga when held under normal farming conditions in the region.

Este estudo avaliou os parâmetros hematológicos de híbridos tambacu e patinga cultivados no Mato Grosso do Sul, Brasil, com ênfase na influência das épocas do ano. Duzentos e quarenta peixes híbridos, 120 tambacus e 120 patingas, foram coletados ao longo de 12 meses para análises hematológicas, comparando a estação quente (Outubro-Março) com a estação fria (Abril-Setembro). Os parâmetros de qualidade de água foram medidos semanalmente, para verificar sua influência sobre os parâmetros hematológicos. A estação quente mostrou tendência ao declínio nos níveis de oxigênio dissolvido, enquanto na estação fria ocorreu o inverso. Na estação quente, tambacus apresentaram valores mais altos (p<0,05) de proteína plasmática total (TPP), concentração de hemoglobina, volume corpuscular médio (MCV), concentração de hemoglobina corpuscular média (MCHC) e número de eosinófilos. Na estação fria, as contagens de eritrócitos, trombócitos, leucócitos totais, linfócitos e neutrófilos foram mais altas (p<0,05). Em patingas, valores mais altos de MCV foram observados na estação quente, enquanto a concentração de hemoglobina, eritrócitos, MCHC, leucócitos totais e basófilos foram mais altos (p<0,05) na estação fria. Os resultados mostram influência da sazonalidade sobre os parâmetros hematológicos dos híbridos tambacu e patinga mantidos em condições típicas de cultivo na região.