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.

Length-weight relationship: eight species of Cyprinidae from river Panjkora, Khyber Pakhtunkhwa, Pakistan / Relação peso-comprimento: oito espécies de Cyprinidae do rio Panjkora, Khyber Pakhtunkhwa, Paquistão

Seven hundred and twenty four fish specimens were captured from March to September 2016. The materials used in the current study were cast nets, hand nets. Eight cyprinid fish species were studied for their length weight relationships. Parameter b in the LWR was 3.03, 3.06, 3.02, 2.29, 2.82, 3.43, 2.73 and 2.47 for Schizothorax plagiostomus, Schizothorax esocinus, Racoma labiata, Tor putitora, Barilius vagra, Garra gotyla, Puntius ticto and Arassius auratus respectively. Current study is the first attempt on the LWRs of cyprinid species, provide a baseline approach for conservation and /management of local fish fauna of economic importance.

Um total de 724 espécimes de peixes foi capturado de março a setembro de 2016. Os materiais usados no presente estudo foram redes de lançamento, redes de mão. Oito espécies de peixes ciprinídeos foram estudadas quanto às suas relações peso/comprimento. O parâmetro b no LWR foi 3,03, 3,06, 3,02, 2,29, 2,82, 3,43, 2,73 e 2,47 para Schizothorax plagiostomus, Schizothorax esocinus, Racoma labiata, Tor putitora, Barilius vagra, Garra gotyla, Puntius ticto e Arassius auratus respectivamente. O estudo atual é a primeira tentativa sobre os LWRs de espécies de ciprinídeos, fornecendo uma abordagem de base para a conservação e o manejo da ictiofauna local de importância econômica.

Use of antioxidants and time of cold storage: effects over viability parameters and enzymatic levels in semen of rainbow trout (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.

Length-weight relationship: eight species of Cyprinidae from river Panjkora, Khyber Pakhtunkhwa, Pakistan

Abstract Seven hundred and twenty four fish specimens were captured from March to September 2016. The materials used in the current study were cast nets, hand nets. Eight cyprinid fish species were studied for their length-weight relationships. Parameter b in the LWR was 3.03, 3.06, 3.02, 2.29, 2.82, 3.43, 2.73 and 2.47 for Schizothorax plagiostomus, Schizothorax esocinus, Racoma labiata, Tor putitora, Barilius vagra, Garra gotyla, Puntius ticto and Arassius auratus respectively. Current study is the first attempt on the LWRs of cyprinid species, provide a baseline approach for conservation and /management of local fish fauna of economic importance.

Resumo Um total de 724 espécimes de peixes foi capturado de março a setembro de 2016. Os materiais usados no presente estudo foram redes de lançamento, redes de mão. Oito espécies de peixes ciprinídeos foram estudadas quanto às suas relações peso/comprimento. O parâmetro b no LWR foi 3,03, 3,06, 3,02, 2,29, 2,82, 3,43, 2,73 e 2,47 para Schizothorax plagiostomus, Schizothorax esocinus, Racoma labiata, Tor putitora, Barilius vagra, Garra gotyla, Puntius ticto e Arassius auratus respectivamente. O estudo atual é a primeira tentativa sobre os LWRs de espécies de ciprinídeos, fornecendo uma abordagem de base para a conservação e o manejo da ictiofauna local de importância econômica.

Length-weight relationship: eight species of Cyprinidae from river Panjkora, Khyber Pakhtunkhwa, Pakistan / Relação peso-comprimento: oito espécies de Cyprinidae do rio Panjkora, Khyber Pakhtunkhwa, Paquistão

Abstract Seven hundred and twenty four fish specimens were captured from March to September 2016. The materials used in the current study were cast nets, hand nets. Eight cyprinid fish species were studied for their length-weight relationships. Parameter b in the LWR was 3.03, 3.06, 3.02, 2.29, 2.82, 3.43, 2.73 and 2.47 for Schizothorax plagiostomus, Schizothorax esocinus, Racoma labiata, Tor putitora, Barilius vagra, Garra gotyla, Puntius ticto and Arassius auratus respectively. Current study is the first attempt on the LWRs of cyprinid species, provide a baseline approach for conservation and /management of local fish fauna of economic importance.

Resumo Um total de 724 espécimes de peixes foi capturado de março a setembro de 2016. Os materiais usados ​​no presente estudo foram redes de lançamento, redes de mão. Oito espécies de peixes ciprinídeos foram estudadas quanto às suas relações peso/comprimento. O parâmetro b no LWR foi 3,03, 3,06, 3,02, 2,29, 2,82, 3,43, 2,73 e 2,47 para Schizothorax plagiostomus, Schizothorax esocinus, Racoma labiata, Tor putitora, Barilius vagra, Garra gotyla, Puntius ticto e Arassius auratus respectivamente. O estudo atual é a primeira tentativa sobre os LWRs de espécies de ciprinídeos, fornecendo uma abordagem de base para a conservação e o manejo da ictiofauna local de importância econômica.

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.

Composición del sedimento del sistema afluente-laguna de oxidación-efluente, en una granja intensiva de Oncorhynchus mykiss / Sediment Composition of the System Affluent-Oxidation Pool-Effluent in an Intensive Farm of Oncorhynchus mykiss

Resumen El sedimento es la capa superficial del fondo en estanques o en lagunas de oxidación. Este se origina fundamentalmente por la deposición de sólidos en suspensión, nutrientes y partículas del suelo que están en contacto con el agua, y que son naturalmente producidos por la operación de las granjas. Su manejo y disposición se constituye actualmente en un imperativo técnico, dadas las implicaciones ambientales que tienen las descargas provenientes de cultivos piscícolas. Se realizó la caracterización general del sedimento en tres sectores de una granja intensiva de producción, afluente, laguna de oxidación y efluente, la cual incluyó cuatro parámetros, que fueron medidos en tres momentos diferentes. Los valores obtenidos fueron comparados mediante análisis de varianza de una vía con α = 0,05 como nivel de significancia. Además, cuando fue necesario se realizó una prueba de Tukey para precisar las diferencias. Aquello cobijó las medidas de fósforo disponible, materia orgánica, carbono orgánico y relación C: N. Las diferencias encontradas entre los sectores son una aproximación al efecto de la producción piscícola sobre la composición de los sedimentos.

Abstract Sediment is the surface layer in the bottom of ponds or oxidation pools. It is created basically due to the deposition of solids in suspension, nutrients, and soil particles that contact the water and are produced naturally in farming operations. Today, the management and arrangement are a must in technical issues due to the environmental implications generated by the discharges coming from fish cultures. The general characterization of the sediment was carried out in three sectors of an intensive production farm, affluent, oxidation pool, and effluent. It included four parameters that were measured in three different time points. Obtained values were compared using one-way variance analysis with α = 0.05 as the significance level. In addition, when necessary, a Tukey test was carried out to pin down the differences. It enabled us to find the measures of available phosphorus, organic matter, organic carbon, and the ratio C: N. the differences found between the sectors are approximate values to the effect of the fish production regarding the sediment composition.

Prevalence of rhabdochoniasis in snow trout of river Swat and river Panjkora, Khyber Pakhtunkhwa province, Pakistan / Prevalência de rabdoconíase em trutas das neves do rio Swat e do rio Panjkora, província de Khyber Pakhtunkhwa, Paquistão

This research was aimed to explore the helminth parasitic diseases in Schizothorax plagiostomus (the snow trout) from river Swat and river Panjkora, Pakistan. Collection of 360 fish specimens have done from the lower, middle and upper reaches of both the rivers through gill nets, cast nets, dragon nets and hooks. All the samples were examined in the University of Malakand, Zoology Department for helminth parasites during the months from January 2015 to December 2016. Of the total examined fish samples 21.9% (n=79) were infected with Rhabdochona spp including 17.7% (n=32/180) in river Swat and 26.6% (n=47/180) in river Panjkora. Highest month-wise prevalence (p=0.09878,p0.05) prevalence (28.8%) than males (16.6%). Fishes of the lower reaches had highest (p=0.0029, P>0.05) prevalence (31.7%) followed by middle reaches (16.5%) while the lowest prevalence was observed in samples of fish collected from upper reaches (9.87%). Present study address that Rhabdochona spp in the intestine of snow trout has a long term relationship and call as a natural infection in cyprinids and zoonotic risk to human.

Esta pesquisa teve como objetivo explorar as doenças parasitárias por helmintos em Schizothorax plagiostomus (a truta das neves) do rio Swat e do rio Panjkora, Paquistão. A coleta de 360 espécimes de peixes foi feita nos trechos inferior, médio e superior de ambos os rios por meio de redes de emalhar, de lançamento, de dragão e anzóis. Todas as amostras foram examinadas na Universidade de Malakand, Departamento de Zoologia, para helmintos parasitas durante os meses de janeiro de 2015 a dezembro de 2016. Do total de amostras de peixes examinadas, 21,9% (n = 79) estavam infectados com Rhabdochona spp, incluindo 17,7% (n = 32/180) no rio Swat e 26,6% (n = 47/180) no rio Panjkora. A maior prevalência no mês (p = 0,09878, p 0,05) prevalência (28,8%) do que o masculino (16,6%). Os peixes do curso inferior tiveram maior (p = 0,0029, P> 0,05) prevalência (31,7%) seguida do curso médio (16,5%), enquanto a menor prevalência foi observada em amostras de peixes coletados do curso superior (9,87%). O presente estudo aborda que Rhabdochona spp no intestino da truta das neves tem uma relação de longo prazo e pode ser considerada uma infecção natural em ciprinídeos e risco zoonótico para humanos.

Prevalence of rhabdochoniasis in snow trout of river Swat and river Panjkora, Khyber Pakhtunkhwa province, Pakistan

ABSTRACT This research was aimed to explore the helminth parasitic diseases in Schizothorax plagiostomus (the snow trout) from river Swat and river Panjkora, Pakistan. Collection of 360 fish specimens have done from the lower, middle and upper reaches of both the rivers through gill nets, cast nets, dragon nets and hooks. All the samples were examined in the University of Malakand, Zoology Department for helminth parasites during the months from January 2015 to December 2016. Of the total examined fish samples 21.9% (n=79) were infected with Rhabdochona spp including 17.7% (n=32/180) in river Swat and 26.6% (n=47/180) in river Panjkora. Highest month-wise prevalence (p=0.09878,p 0.05) was reported in May (30%), then by February and October each (26.6%) while the lowest during August (13.3%). Highest prevalence (p=0.9723, p 0.05) was reported in summer season (26.6%), while lowest in the winter season (20%). Adults were highly infected (p= 0.0001) in prevalence (63.7%) followed by sub-adults (13.2%) while no infection was found in juvenile specimens. Females fish samples had higher (p=0.0277, p>0.05) prevalence (28.8%) than males (16.6%). Fishes of the lower reaches had highest (p=0.0029, P>0.05) prevalence (31.7%) followed by middle reaches (16.5%) while the lowest prevalence was observed in samples of fish collected from upper reaches (9.87%). Present study address that Rhabdochona spp in the intestine of snow trout has a long term relationship and call as a natural infection in cyprinids and zoonotic risk to human.

Resumo Esta pesquisa teve como objetivo explorar as doenças parasitárias por helmintos em Schizothorax plagiostomus (a truta das neves) do rio Swat e do rio Panjkora, Paquistão. A coleta de 360 espécimes de peixes foi feita nos trechos inferior, médio e superior de ambos os rios por meio de redes de emalhar, de lançamento, de dragão e anzóis. Todas as amostras foram examinadas na Universidade de Malakand, Departamento de Zoologia, para helmintos parasitas durante os meses de janeiro de 2015 a dezembro de 2016. Do total de amostras de peixes examinadas, 21,9% (n = 79) estavam infectados com Rhabdochona spp, incluindo 17,7% (n = 32/180) no rio Swat e 26,6% (n = 47/180) no rio Panjkora. A maior prevalência no mês (p = 0,09878, p 0,05) foi relatada em maio (30%), depois em fevereiro e outubro cada (26,6%), enquanto a menor em agosto (13,3%). A maior prevalência (p = 0,9723, p 0,05) foi relatada no verão (26,6%), enquanto a menor no inverno (20%). Os adultos foram altamente infectados (p = 0,0001) na prevalência (63,7%), seguidos por subadultos (13,2%), enquanto nenhuma infecção foi encontrada em espécimes juvenis. As amostras de peixes do sexo feminino tiveram maior (p = 0,0277, p> 0,05) prevalência (28,8%) do que o masculino (16,6%). Os peixes do curso inferior tiveram maior (p = 0,0029, P> 0,05) prevalência (31,7%) seguida do curso médio (16,5%), enquanto a menor prevalência foi observada em amostras de peixes coletados do curso superior (9,87%). O presente estudo aborda que Rhabdochona spp no intestino da truta das neves tem uma relação de longo prazo e pode ser considerada uma infecção natural em ciprinídeos e risco zoonótico para humanos.

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.

Prevalence of rhabdochoniasis in snow trout of river Swat and river Panjkora, Khyber Pakhtunkhwa province, Pakistan / Prevalência de rabdoconíase em trutas das neves do rio Swat e do rio Panjkora, província de Khyber Pakhtunkhwa, Paquistão

This research was aimed to explore the helminth parasitic diseases in Schizothorax plagiostomus (the snow trout) from river Swat and river Panjkora, Pakistan. Collection of 360 fish specimens have done from the lower, middle and upper reaches of both the rivers through gill nets, cast nets, dragon nets and hooks. All the samples were examined in the University of Malakand, Zoology Department for helminth parasites during the months from January 2015 to December 2016. Of the total examined fish samples 21.9% (n=79) were infected with Rhabdochona spp including 17.7% (n=32/180) in river Swat and 26.6% (n=47/180) in river Panjkora. Highest month-wise prevalence (p=0.09878,p<0.05) was reported in May (30%), then by February and October each (26.6%) while the lowest during August (13.3%). Highest prevalence (p=0.9723, p<0.05) was reported in summer season (26.6%), while lowest in the winter season (20%). Adults were highly infected (p=< 0.0001) in prevalence (63.7%) followed by sub-adults (13.2%) while no infection was found in juvenile specimens. Females fish samples had higher (p=0.0277, p>0.05) prevalence (28.8%) than males (16.6%). Fishes of the lower reaches had highest (p=0.0029, P>0.05) prevalence (31.7%) followed by middle reaches (16.5%) while the lowest prevalence was observed in samples of fish collected from upper reaches (9.87%). Present study address that Rhabdochona spp in the intestine of snow trout has a long term relationship and call as a natural infection in cyprinids and zoonotic risk to human.

Esta pesquisa teve como objetivo explorar as doenças parasitárias por helmintos em Schizothorax plagiostomus (a truta das neves) do rio Swat e do rio Panjkora, Paquistão. A coleta de 360 espécimes de peixes foi feita nos trechos inferior, médio e superior de ambos os rios por meio de redes de emalhar, de lançamento, de dragão e anzóis. Todas as amostras foram examinadas na Universidade de Malakand, Departamento de Zoologia, para helmintos parasitas durante os meses de janeiro de 2015 a dezembro de 2016. Do total de amostras de peixes examinadas, 21,9% (n = 79) estavam infectados com Rhabdochona spp, incluindo 17,7% (n = 32/180) no rio Swat e 26,6% (n = 47/180) no rio Panjkora. A maior prevalência no mês (p = 0,09878, p <0,05) foi relatada em maio (30%), depois em fevereiro e outubro cada (26,6%), enquanto a menor em agosto (13,3%). A maior prevalência (p = 0,9723, p <0,05) foi relatada no verão (26,6%), enquanto a menor no inverno (20%). Os adultos foram altamente infectados (p = <0,0001) na prevalência (63,7%), seguidos por subadultos (13,2%), enquanto nenhuma infecção foi encontrada em espécimes juvenis. As amostras de peixes do sexo feminino tiveram maior (p = 0,0277, p> 0,05) prevalência (28,8%) do que o masculino (16,6%). Os peixes do curso inferior tiveram maior (p = 0,0029, P> 0,05) prevalência (31,7%) seguida do curso médio (16,5%), enquanto a menor prevalência foi observada em amostras de peixes coletados do curso superior (9,87%). O presente estudo aborda que Rhabdochona spp no intestino da truta das neves tem uma relação de longo prazo e pode ser considerada uma infecção natural em ciprinídeos e risco zoonótico para humanos.

Effects of elderflower extract enriched with polyphenols on antioxidant defense of salmon leukocytes

BACKGROUND: In fish farming, the plant extracts containing antioxidant compounds have been added to the diet for enhancing pathogen resistance. In vitro studies evaluating the antioxidant effect of herbal extracts on fish cell models have focused on ROS production and the respiratory burst mechanism. However, the effects on enzymatic antioxidant defense on salmon leukocytes have not been evaluated. This study aims to evaluate the enzymatic antioxidant defense and ROS-induced cell damage in Salmon Head Kidney-1 (SHK-1) cell line exposed to polyphenol-enriched extract from Sambucus nigra flowers. RESULTS: Firstly, the Total Reactive Antioxidant Power (TRAP) assay of elderflower polyphenol (EP) was evaluated, showing 459 and 489 times more active than gallic acid and butyl hydroxy toluene (BHT), respectively. The toxic effect of EP on salmon cells was not significant at concentrations below 120 mg/ mL and no hemolysis activity was observed between 20 and 400 mg/mL. The treatment of SHK-1 cell line with EP decreased both the lipid peroxidation and protein oxidation induced by H2O2, which could be associated with decreasing oxidative stress in the SHK-1 cells since the GSH/GSSG ratio increased when only EP was added. CONCLUSIONS: These results suggest that plant extracts enriched with polyphenols could improve the enzymatic antioxidant defense of salmon leukocytes and protect the cells against ROS-induced cell damage

Assessment of ecto and endo parasites of Schizothorax plagiostomus inhabiting river Panjkora, Khyber Pakhtunkhwa, Pakistan / Avaliação de ecto e endoparasitas de Schizothorax plagiostomus habitantes do rio Panjkora, Khyber Pakhtunkhwa, Paquistão

Abstract Fish provides main source of high quality protein to more than one billion people in the world. Fish parasites directly affect the productivity of fish and indirectly on human health. This research was aimed to assess the helminth parasites in Schizothorax plagiostomus (the snow trout) from river Panjkora, KP, Pakistan. A total of 88 fish samples (n= 88) were collected from the upper, middle and lower regions of the river through cast nets, hand nets and hooks. All the collected fish samples were examined in the Parasitology Laboratory, Department of Zoology, University of Malakand for helminth parasites during July 2018 to February 2019.Among these fishes nematodes, trematodes, cestodes and acanthocephalan were isolated and identified. Overall prevalence of the fish parasites was 60.22% (53/88). The intensity of the parasite was observed from 1.7% to 4.61%. Highest prevalence was reported in summer season 86.36% while lowest in the winter season 36.36%. This study shows that summer season affects the fish business and result in poor quality fish meat with risk of zoonotic diseases. Adults were highly infected 82.25% while no infection was found in juvenile specimens. Female fish samples had higher prevalence 68.22% than males 48.22%. Fishes of the lower reaches had highest prevalence 60.22% than the upper reaches 40.0%. Fish samples with maximum length and weight were highly 76.92% infected than small sized fish with low body weight. Present study addresses that Rhabdochona schizothoracis in the intestine and Diplozoon paradoxum in gills of snow trout fish has a long term relationship and call as a natural infection in cyprinids and it is zoonotic threat to human.

Resumo O peixe é a principal fonte de proteína de alta qualidade para mais de um bilhão de pessoas no mundo. Contudo, parasitas afetam diretamente a produtividade de peixes e, indiretamente, a saúde humana. Esta pesquisa teve como objetivo avaliar os parasitas helmintos em Schizothorax plagiostomus (truta da neve) do rio Panjkora, Khyber Pakhtunkhwa, Paquistão. Foram coletadas 88 amostras de peixes (n = 88) dos trechos alto, médio e baixo do rio por meio de redes de arrasto, redes de mão e varas de pesca. Todas as amostras de peixes coletadas foram examinadas no Laboratório de Parasitologia do Departamento de Zoologia, da Universidade de Malakand, quanto a parasitas helmintos durante o período de julho de 2018 a fevereiro de 2019. Entre esses peixes, nematódeos, trematódeos, cestóideos e acantocéfalos foram isolados e identificados. A prevalência geral de parasitas de peixes foi de 60,22% (53/88). A intensidade do parasita foi observada de 1,7 a 4,61%. A maior prevalência (86,36%) foi relatada no verão, enquanto a menor (36,36%), no inverno. Este estudo mostra que a temporada de verão afeta o ramo da pesca e resulta em carne de baixa qualidade, com risco de doenças zoonóticas. Os adultos foram altamente infectados (82,25%), enquanto nenhuma infecção foi encontrada em jovens. As amostras de peixes do sexo feminino apresentaram maior prevalência (68,22%) do que as do sexo masculino (48,22%). Os peixes coletados no trecho baixo do rio tiveram maior prevalência (60,22%) do que os do trecho alto (40%). Amostras de peixes com comprimento e peso máximos foram altamente infectadas (76,92%) do que peixes de pequeno porte e baixo peso corporal. O presente estudo aborda que Rhabdochona schizothoracis no intestino e Diplozoon paradoxum em brânquias de peixes de truta da neve possuem uma estreita relação que causa uma infecção natural em ciprinídeos, sendo uma ameaça zoonótica ao ser humano.

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.

Toxicity of Zinc at sublethal exposure to rainbow trout (Oncorhynchus mykiss) / Toxicidad de zinc por exposición subletal en trucha arco iris (Oncorhynchus mykiss) / Toxicidade por exposição ao zinco em trutas arco-íris (Oncorhynchus mykiss)

Abstract Zinc (Zn), can alter different physiological processes in fish such as growth and serum parameters. The objective of this study was to investigate the toxicity of Zn on sublethal exposure to rainbow trout (Oncorhnychus mykiss). Fish exposed to higher levels of Zn grew slower than fish exposed to lower levels of Zn. Weight gain and SGR (Specific Growth Rate) decreased linearly as the Zn level in the water increased. The CF (Condition factor) of fish grown in water with a high concentration of Zn also decreased significantly compared to the low concentration of Zn, whereas the Food Conversion Ratio (FCR) increased with the concentration of Zn in water. Both AST (Aspartate Transaminase) and ALT (Alanine Transaminase) activities were significantly altered by Zn and showed a linear pattern and decreased after 30 days, while ALP (Alkaline Phosphatase) levels showed a remarkable increase from a mean level of control. This study suggests that biochemical parameters of growth and serum could be used as important and sensitive biomarkers to monitor heavy metal toxicity on fish health status.

Resumen TZinc (Zn), puede alterar diferentes procesos fisiológicos en peces, tales como, el crecimiento y los parámetros séricos. El objetivo de este estudio fue investigar la toxicidad de Zn en la exposición subletal de la trucha arco iris (Oncorhnychus mykiss). Los peces expuestos a niveles más altos de Zn crecieron más lentamente que los peces expuestos a niveles más bajos de Zn. El aumento de peso y la SGR (tasa de crecimiento específica) disminuyeron linealmente a medida que aumentó el nivel de Zn en el agua. El CF (factor de condición) de los peces cultivados en agua con una alta concentración de Zn, también disminuyó significativamente en comparación con la baja concentración de Zn, mientras que el índice de conversión de alimentos (FCR) aumentó con la concentración de Zn en el agua. Las actividades AST (Aspartate Transaminase) y ALT (Alanine Transaminase) fueron significativamente alteradas por el Zn y mostraron un patrón lineal y disminuyeron después de 30 días, mientras que los niveles de ALP (Fosfatasa Alcalina) mostraron un aumento notable desde un nivel medio de control. Este estudio sugiere que los parámetros bioquímicos de crecimiento y suero podrían usarse como biomarcadores importantes y sensibles para controlar la toxicidad de metales pesados en el estado de salud de los peces.

Resumo O TZinc (Zn) pode alterar diferentes processos fisiológicos em peixes, como parámetros de crescimento e soro. O objetivo deste estudo foi investigar a toxicidade do Zn na exposição subletal à truta arco-íris (Oncorhnychus mykiss). Os peixes expostos a níveis mais altos de Zn cresceram mais lentamente do que os peixes expostos a níveis mais baixos de Zn. O ganho de peso e a SGR (Taxa de Crescimento Específico) diminuíram linearmente à medida que o nível de Zn na água aumentou. O CF (fator de condição) de peixes cultivados em água com alta concentração de Zn também diminuiu significativamente em comparação com a baixa concentração de Zn, enquanto a tax on de conversão alimentar (FCR) aumentou com a concentração de Zn na água. As atividades de AST (Aspartate Transaminase) e ALT (Alanine Transaminase) foram significativamente alteradas pelo Zn e mostraram um padrão linear e diminuíram após 30 dias, enquanto os níveis de ALP (Fosfatase Alcalina) mostraram um aumento notável em relação ao nível médio de controle. Este estudo sugere que parâmetros bioquímicos de crescimento e soro podem ser usados como biomarcadores importantes e sensíveis para monitorar a toxicidade de metais pesados no estado de saúde dos peixes.

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.

Criteria for Safe Use of Plant Ingredients in Diets for Aquacultured Fish

The Norwegian Food Safety Authority (Mattilsynet) asked the Norwegian Scientific Committee for Food Safety (Vitenskapskomiteen for mattrygghet) to assess if the criteria for safe use of plant ingredients in diets for aquacultured fish fulfil the Feed regulative §7 to “not induce negative health effects in the animal”, and in this context aquacultured fish. The use of feed ingredients of both plant and animal origin is set by the regulation “Forskrift 7. November 2002 nr 1290”, and amendments. The objective of the regulation is to protect animals, consumers and the environment. For animals, the feed shall not pose a risk, or danger, to their health. Aspects to be assessed were whether the changes in fish diet ingredient composition seen in recent years with high levels of plant ingredients, plus additions of immunostimulants, would in any manner challenge fish health and if any ingredient should be limited due to its negative effect, or induce any long-term negative effect. “Long-term” here extends beyond normal production time for consumption, e.g. when substances that might affect fish health are included in broodstock diets. Atlantic salmon (Salmo salar), rainbow trout (Onchorhyncus mykiss), Atlantic halibut (Hippoglossus hippoglossus) and Atlantic cod (Gadus morhua) should especially be addressed. However, since all life stages should be included, especially broodstock, and also possible long-term effects, and literature on these for the requested species is scarce, the assessment mentions studies on other species when relevant. With the exception of full-fat and extracted soybean meal for salmonids, substituting at least part of the fishmeal fraction of aquafeeds with individual plant ingredients is promising, at least in the short to medium term. Indeed in some cases, diets containing up to 20% inclusion level of high-quality plant protein sources have resulted in better nutrient digestibility and growth parameters than the fishmeal-based control diets. When substituting fishmeal with plant ingredients, however, it is necessary to balance the diets regarding limiting amino acids and minerals. Adding plant proteins to fish diets result in the introduction of anti-nutritional factors. There is an urgent need to investigate consequences of various anti-nutritional factors, individually and in combinations, to nutrient digestibility, utilization and metabolism as well as to intestinal function, structure, defence mechanisms and microbiota. Long-term effects also merit investigation. This will aid in the ability to predict how a newly introduced plant ingredient as well as combinations of plant ingredients may affect the fish and identify steps needed to avoid adverse health effects. As many of the potential disadvantages of using plant oils in salmonid diets are related to either very high levels of n-6 PUFA (most available oils) or very high levels of linseed oil, it would be recommended that mixtures of plant oils should be used as feed inclusions. By adjusting the ratio of n-6 and n-3 the level of eicosanoids can be controlled. By including palm oil, potential problems in lipid digestibility and transport can be controlled. A standard inclusion of soybean lecithin may also be advisory. These and other variants of mixtures of oil sources have been explored in recent years with some success in salmonid fish. Such mixtures do not seem to be necessary for marine fish. Modern finfish aquaculture faces problems such as bone and skeletal deformities, cataracts, heart disorders, unspecific ulceration and various digestive disorders including intestinal colic in Atlantic cod, gastric dilatation (bloat) in rainbow trout, and intestinal tumours, at low incidence, in Atlantic salmon broodstock. Most of the mentioned problems have been related to malnutrition, feed, intensive growth and/or unfavourable environmental conditions. The disorders are often not lethal, but may imply a fish welfare problem and increase the susceptibility to secondary disorders and infectious diseases. Major changes in feed composition and feed ingredients may increase the risk for such production-related disorders in intensive fish farming. Care should be taken when choosing plant alternatives, both types and qualities, to prevent nutrition-related diseases such as skeletal deformities, cataracts, heart conditions, and other, unspecific symptoms. The change from marine- to plant-based diet ingredients, results in changed profile and content of undesirable substances. The list of undesirable substances included in the feed legislation is, in general, sufficient, but it should be considered to include pesticides in use today and more of the mycotoxins. Currently only aflatoxin B1 is included, while only recommendations exist for other mycotoxins. Studies of dietary exposure to undesirable substances, e.g. pesticides and mycotoxins, and their toxic effects and toxicokinetics in fish are scarce. To date, the application of pre- and probiotics for the improvement of aquatic environmental quality and for disease control in aquaculture seems promising; however, the information is limited and sometimes contradictory. Currently there are numerous gaps in existing knowledge about exogenous nucleotide application to fish including various aspects of digestion, absorption, metabolism, and influences on various physiological responses, especially expression of immunogenes and modulation of immunoglobulin production. As limited information is available about the effect of immunostimulants, prebiotics and nucleotides on gut morphology, this topic should be given high priority in future studies. Heat processing of raw materials and of the complete fish diets may potentially alter nutritional properties of plant materials. However, the negative effects appear to be modest under practical conditions.

Preparation of Rainbow Trout Bone Oil by Aqueous Enzymatic Methodand Identification by Gas Chromatography-Mass Spectrometry / 分析化学

Fish oil is an important nutrient component in rainbow trout bone, and the optimization of extraction by enzymatic hydrolytic method is of great significance.This study selected the alkaline protease as the hydrolytic enzyme, and optimized the process conditions of enzymatic hydrolysis of rainbow trout fish using single factor analysis method.Effects of several factors on the extraction of fish oil were studied, including the ratio of material to liquid, pH, enzymatic hydrolysis time, enzymatic hydrolysis temperature and amount of enzyme.Fatty acids were identified by gas chromatography-mass spectrometry (GC-MS).Results showed that the optimum extraction parameters of enzymatic hydrolysis were as follows: 2000 U/g alkaline protease, ratio of material to liquid of 1∶1 (w/w), pH 7.5, and extraction at 55℃ for 3h.It was found that the main composition of rainbow trout bone oil was unsaturated fatty acid with the content of 80.4% (w/w).The relative content of monounsaturated fatty acid and polyunsaturated fatty acid was about 76.9% (w/w) and 23.1% (w/w), respectively.The total content of EPA and DHA was 3.4% (w/w).This study optimized the extraction method of rainbow trout fish oil, analyzed and identified the main volatile compounds, and identified the main substances contributing to fish oil flavor.The method thus was of significance for the analysis and identification of fish oil products.

Assessment and incidence of fish associated bacterial pathogens at hatcheries of Azad Kashmir, Pakistan

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.