Predation of Piaractus mesopotamicus and Oreochromis niloticus larvae by Pantala flavescens with different length classes - doi: 10.4025/actascibiolsci.v33i4.5470 / Predation of Piaractus mesopotamicus and Oreochromis niloticus larvae by Pantala flavescens with different length classes - doi: 10.4025/actascibiolsci.v33i4.5470

The experiment had as objective to study the survival of Piaractus mesopotamicus and Oreochromis niloticus larvae subject to predation by Pantala flavescens larvae with different length classes. We used 120 larvae of P. mesopotamicus, 120 of O. niloticus, and also 24 larvae of Pantala flavescens, distributed in 24 aquariums with useful volume for 2 L, being placed one Odonate for aquarium. The treatments differed as regard to the prey species and the predator size, being kept a control treatment. An aquarium (2 L) containing one larvae of Odonate and 10 larvae of fish were considered an experimental unit. After the beginning, each three hours (18:00, 21:00, 0:00, 3:00, 6:00, 9:00, 12:00, 15:00 and 18:00h), the remnant larvae of fish (alive) in each experimental unit was quantified, and we replaced the consumed larvae, so that we always had 10 larvae of fish at each aquarium after each counting. For both fish species, there was a slight increase in consumption by the Odonate with intermediate size, but the values did not differ statistically (p > 0.05). Larvae of Odonate in the treatments with greater length presented a lower consumption (p 0.05) than in other treatments.

The experiment had as objective to study the survival of Piaractus mesopotamicus and Oreochromis niloticus larvae subject to predation by Pantala flavescens larvae with different length classes. We used 120 larvae of P. mesopotamicus, 120 of O. niloticus, and also 24 larvae of Pantala flavescens, distributed in 24 aquariums with useful volume for 2 L, being placed one Odonate for aquarium. The treatments differed as regard to the prey species and the predator size, being kept a control treatment. An aquarium (2 L) containing one larvae of Odonate and 10 larvae of fish were considered an experimental unit. After the beginning, each three hours (18:00, 21:00, 0:00, 3:00, 6:00, 9:00, 12:00, 15:00 and 18:00h), the remnant larvae of fish (alive) in each experimental unit was quantified, and we replaced the consumed larvae, so that we always had 10 larvae of fish at each aquarium after each counting. For both fish species, there was a slight increase in consumption by the Odonate with intermediate size, but the values did not differ statistically (p > 0.05). Larvae of Odonate in the treatments with greater length presented a lower consumption (p 0.05) than in other treatments.

Predation of Piaractus mesopotamicus and Oreochromis niloticus larvae by Pantala flavescens with different length classes - doi: 10.4025/actascibiolsci.v33i4.5470 / Predation of Piaractus mesopotamicus and Oreochromis niloticus larvae by Pantala flavescens with different length classes - doi: 10.4025/actascibiolsci.v33i4.5470

The experiment had as objective to study the survival of Piaractus mesopotamicus and Oreochromis niloticus larvae subject to predation by Pantala flavescens larvae with different length classes. We used 120 larvae of P. mesopotamicus, 120 of O. niloticus, and also 24 larvae of Pantala flavescens, distributed in 24 aquariums with useful volume for 2 L, being placed one Odonate for aquarium. The treatments differed as regard to the prey species and the predator size, being kept a control treatment. An aquarium (2 L) containing one larvae of Odonate and 10 larvae of fish were considered an experimental unit. After the beginning, each three hours (18:00, 21:00, 0:00, 3:00, 6:00, 9:00, 12:00, 15:00 and 18:00h), the remnant larvae of fish (alive) in each experimental unit was quantified, and we replaced the consumed larvae, so that we always had 10 larvae of fish at each aquarium after each counting. For both fish species, there was a slight increase in consumption by the Odonate with intermediate size, but the values did not differ statistically (p > 0.05). Larvae of Odonate in the treatments with greater length presented a lower consumption (p 0.05) than in other treatments.

The experiment had as objective to study the survival of Piaractus mesopotamicus and Oreochromis niloticus larvae subject to predation by Pantala flavescens larvae with different length classes. We used 120 larvae of P. mesopotamicus, 120 of O. niloticus, and also 24 larvae of Pantala flavescens, distributed in 24 aquariums with useful volume for 2 L, being placed one Odonate for aquarium. The treatments differed as regard to the prey species and the predator size, being kept a control treatment. An aquarium (2 L) containing one larvae of Odonate and 10 larvae of fish were considered an experimental unit. After the beginning, each three hours (18:00, 21:00, 0:00, 3:00, 6:00, 9:00, 12:00, 15:00 and 18:00h), the remnant larvae of fish (alive) in each experimental unit was quantified, and we replaced the consumed larvae, so that we always had 10 larvae of fish at each aquarium after each counting. For both fish species, there was a slight increase in consumption by the Odonate with intermediate size, but the values did not differ statistically (p > 0.05). Larvae of Odonate in the treatments with greater length presented a lower consumption (p 0.05) than in other treatments.

Replacement of corn Zea mays L. by cassava Manihot esculenta crants meal in grass-carp Ctenopharyngodon idella fingerlings diets - DOI: 10.4025/actascianimsci.v27i2.1228 / Farelo de mandioca (Manihot esculenta) Crants em substituição ao milho (Zea mays L.) em rações para alevinos de carpa-capim (Ctenopharyngodon idella) - DOI: 10.4025/actascianimsci.v27i2.1228

The experiment was carried out aiming to evaluate different substitution levels of corn by cassava meal in grass carp ctenopharyngodon idella fingerlings diets. It was used 120 fingerlings with initial live weigh of 2.51+0.05 g, distributed in 24 net ponds at a randomized blocks design with six treatments and four replications, each block corresponding to a fiber-ciment 1000 L tank with six net ponds (120 L) inside. Each net ponds with five fingerlings was considered an experimental unit. The treatments consisted in rations (32% crude protein and 3000 kcal/kg digestible energy) with different cassava meal inclusion levels of (0.00, 5.99, 11.98, 17.97, 23.95, 29.94) corresponding a 00.0, 20.0, 40.0, 60.0, 80.0 e 100.0% of replacement of corn. Effect were not observed of cassava-by-product meal inclusion levels on the final weight, final length, feed: gain, condition index and survival rate of grass carp ctenopharyngodon idella fingerlings. The water physical-chemical parameters were 22.92oC, 24.54oC 6.38 mg/L, 7.47 e 0.16 ms/cm, respectively to morning temperature, afternoon temperature, dissolved oxygen, ph and electric conduct. It may be concluded that the cassava meal can substitute the corn in even 100% in grass carp fingerlings diets

O experimento foi realizado com o objetivo de avaliar a substituição do milho pelo farelo de mandioca em rações para alevinos de Carpa-capim (Ctenopharyngodon idella). Foram utilizados 120 alevinos de Carpa-capim, com peso vivo inicial de 2,51+ 0,05 g, distribuídos em 24 tanques-rede, em um delineamento em blocos casualizados com seis tratamentos e quatro repetições, cada bloco correspondendo a uma caixa de fibrocimento com 1.000 L de capacidade, com seis tanques-rede (120 L) em seu interior. Cada tanque-rede com cinco alevinos foi considerado uma unidade experimental. Os tratamentos consistiam em rações (32% de proteína bruta e 3000 kcal/kg de energia digestível) com diferentes níveis de inclusão de farelo de mandioca (0.00; 5.99; 11.98; 17.97; 23.95; 29.94), correspondendo a substituição de 0.0%; 20.0%; 40.0%; 60.0%; 80.0% e 100.0% do milho na ração. Não foram observados efeitos dos níveis de inclusão do farelo de mandioca sobre o peso final, comprimento final, conversão alimentar, fator de condição e sobrevivência dos alevinos. Os parâmetros físico-químicos médios da água foram 22,92oC, 24,54oC, 6,38 mg/L, 7,47; 0,16 mS/cm, respectivamente para temperatura matutina, temperatura vespertina, oxigênio dissolvido, pH e condutividade. Conclui-se que e farelo de varredura de mandioca pode substituir o milho em até 100% nas rações para alevinos de carpa-capim

Replacement of corn Zea mays by millet Pennisetum americanum in grass carp Ctenopharyngodon idella fingerlings diets - DOI: 10.4025/actascibiolsci.v27i1.1365 / Substituição do milho Zea mays por milheto Pennisetum americanum em rações para alevinos de carpa-capim Ctenopharyngodon idella - DOI: 10.4025/actascibiolsci.v27i1.1365

The present experiment was carried out to evaluate the effects of the replacement of corn Zea. Mays (0.00%; 33.00%; 66.67% e 100.00%) by millet P. americanum in grass carp Ctenopharyngodon idella fingerlings diets, during a 45 days period. One hundred and twelve carp grass fingerlings (0.75 g) were used, distributed in 16 net ponds (160 L), in randomized blocks with four treatments and four replicates. Each block corresponded to one fiber cement tank (1000 L) with four net ponds. Each net pond containing seven grass carp fingerlings was considered one experimental unit. The variables evaluated were: mean weight, mean weight gain, mean length, outward feed conversion, condition factor and survival rate. Differences on the performance parameters of the animals were not observed. The average values of temperature, pH, electric conductivity and dissolved oxygen was 24.5th C ± 1.39; 7.51 ± 0.32; 0.16 ± 0.01 µS/cm and 6.04 ± 1.28 mg/L, respectively. Results show that the millet can be included in Ctenopharyngodon idella fingerlings diets up to 33.70%, replacing the corn completely, without affecting the performance of the fish

O presente experimento com duração de 45 dias foi conduzido com o objetivo de avaliar o efeito da substituição do milho Zea mays (0,00%; 33,00%; 66,67% e 100,00%) pelo milheto Pennisetum americanum, em rações sobre o desempenho de alevinos de carpa-capim Ctenopharyngodon idella. Foram utilizados 112 alevinos de carpa-capim (0,75 g), distribuídos em 16 tanques-rede (160 L), em um delineamento em blocos casualizados, com 4 tratamentos e 4 repetições. Cada bloco correspondeu a uma caixa de fibrocimento (1.000 L) com 4 tanques-rede, onde cada um deles contendo 7 alevinos foi considerado uma unidade experimental. As variáveis avaliadas foram peso final médio, ganho de peso, comprimento final médio, conversão alimentar aparente, fator de condição e taxa de sobrevivência. Não foram observados efeitos da utilização do milheto sobre os parâmetros de desempenho produtivo analisados (p > 0,01). Os valores médios de temperatura, pH, condutividade elétrica e oxigênio dissolvido durante o período experimental foram de 24,5 ± 1,39ºC; 7,51 ± 0,32; 0,16 ± 0,01 µS/cm e 6,04 ± 1,28 mg/L, respectivamente. Conclui-se que o milheto pode ser incluído na ração para alevinos de C. idella em até 33,7%, substituindo totalmente o milho sem afetar o desempenho dos animais

Replacement of corn Zea mays L. by cassava Manihot esculenta crants meal in grass-carp Ctenopharyngodon idella fingerlings diets - DOI: 10.4025/actascianimsci.v27i2.1228 / Farelo de mandioca (Manihot esculenta) Crants em substituição ao milho (Zea mays L.) em rações para alevinos de carpa-capim (Ctenopharyngodon idella) - DOI: 10.4025/actascianimsci.v27i2.1228

The experiment was carried out aiming to evaluate different substitution levels of corn by cassava meal in grass carp ctenopharyngodon idella fingerlings diets. It was used 120 fingerlings with initial live weigh of 2.51+0.05 g, distributed in 24 net ponds at a randomized blocks design with six treatments and four replications, each block corresponding to a fiber-ciment 1000 L tank with six net ponds (120 L) inside. Each net ponds with five fingerlings was considered an experimental unit. The treatments consisted in rations (32% crude protein and 3000 kcal/kg digestible energy) with different cassava meal inclusion levels of (0.00, 5.99, 11.98, 17.97, 23.95, 29.94) corresponding a 00.0, 20.0, 40.0, 60.0, 80.0 e 100.0% of replacement of corn. Effect were not observed of cassava-by-product meal inclusion levels on the final weight, final length, feed: gain, condition index and survival rate of grass carp ctenopharyngodon idella fingerlings. The water physical-chemical parameters were 22.92oC, 24.54oC 6.38 mg/L, 7.47 e 0.16 ms/cm, respectively to morning temperature, afternoon temperature, dissolved oxygen, ph and electric conduct. It may be concluded that the cassava meal can substitute the corn in even 100% in grass carp fingerlings diets

O experimento foi realizado com o objetivo de avaliar a substituição do milho pelo farelo de mandioca em rações para alevinos de Carpa-capim (Ctenopharyngodon idella). Foram utilizados 120 alevinos de Carpa-capim, com peso vivo inicial de 2,51+ 0,05 g, distribuídos em 24 tanques-rede, em um delineamento em blocos casualizados com seis tratamentos e quatro repetições, cada bloco correspondendo a uma caixa de fibrocimento com 1.000 L de capacidade, com seis tanques-rede (120 L) em seu interior. Cada tanque-rede com cinco alevinos foi considerado uma unidade experimental. Os tratamentos consistiam em rações (32% de proteína bruta e 3000 kcal/kg de energia digestível) com diferentes níveis de inclusão de farelo de mandioca (0.00; 5.99; 11.98; 17.97; 23.95; 29.94), correspondendo a substituição de 0.0%; 20.0%; 40.0%; 60.0%; 80.0% e 100.0% do milho na ração. Não foram observados efeitos dos níveis de inclusão do farelo de mandioca sobre o peso final, comprimento final, conversão alimentar, fator de condição e sobrevivência dos alevinos. Os parâmetros físico-químicos médios da água foram 22,92oC, 24,54oC, 6,38 mg/L, 7,47; 0,16 mS/cm, respectivamente para temperatura matutina, temperatura vespertina, oxigênio dissolvido, pH e condutividade. Conclui-se que e farelo de varredura de mandioca pode substituir o milho em até 100% nas rações para alevinos de carpa-capim

Replacement of corn Zea mays by millet Pennisetum americanum in grass carp Ctenopharyngodon idella fingerlings diets - DOI: 10.4025/actascibiolsci.v27i1.1365 / Substituição do milho Zea mays por milheto Pennisetum americanum em rações para alevinos de carpa-capim Ctenopharyngodon idella - DOI: 10.4025/actascibiolsci.v27i1.1365

The present experiment was carried out to evaluate the effects of the replacement of corn Zea. Mays (0.00%; 33.00%; 66.67% e 100.00%) by millet P. americanum in grass carp Ctenopharyngodon idella fingerlings diets, during a 45 days period. One hundred and twelve carp grass fingerlings (0.75 g) were used, distributed in 16 net ponds (160 L), in randomized blocks with four treatments and four replicates. Each block corresponded to one fiber cement tank (1000 L) with four net ponds. Each net pond containing seven grass carp fingerlings was considered one experimental unit. The variables evaluated were: mean weight, mean weight gain, mean length, outward feed conversion, condition factor and survival rate. Differences on the performance parameters of the animals were not observed. The average values of temperature, pH, electric conductivity and dissolved oxygen was 24.5th C ± 1.39; 7.51 ± 0.32; 0.16 ± 0.01 µS/cm and 6.04 ± 1.28 mg/L, respectively. Results show that the millet can be included in Ctenopharyngodon idella fingerlings diets up to 33.70%, replacing the corn completely, without affecting the performance of the fish

O presente experimento com duração de 45 dias foi conduzido com o objetivo de avaliar o efeito da substituição do milho Zea mays (0,00%; 33,00%; 66,67% e 100,00%) pelo milheto Pennisetum americanum, em rações sobre o desempenho de alevinos de carpa-capim Ctenopharyngodon idella. Foram utilizados 112 alevinos de carpa-capim (0,75 g), distribuídos em 16 tanques-rede (160 L), em um delineamento em blocos casualizados, com 4 tratamentos e 4 repetições. Cada bloco correspondeu a uma caixa de fibrocimento (1.000 L) com 4 tanques-rede, onde cada um deles contendo 7 alevinos foi considerado uma unidade experimental. As variáveis avaliadas foram peso final médio, ganho de peso, comprimento final médio, conversão alimentar aparente, fator de condição e taxa de sobrevivência. Não foram observados efeitos da utilização do milheto sobre os parâmetros de desempenho produtivo analisados (p > 0,01). Os valores médios de temperatura, pH, condutividade elétrica e oxigênio dissolvido durante o período experimental foram de 24,5 ± 1,39ºC; 7,51 ± 0,32; 0,16 ± 0,01 µS/cm e 6,04 ± 1,28 mg/L, respectivamente. Conclui-se que o milheto pode ser incluído na ração para alevinos de C. idella em até 33,7%, substituindo totalmente o milho sem afetar o desempenho dos animais