RESUMO -Objetivou-se, nesta pesquisa, avaliar o efeito da densidade de estocagem sobre o desenvolvimento de girinos de rã-touro em tanques-rede. Foram utilizados 360 girinos com peso médio inicial 0,01g e comprimento inicial médio de 0,92±0,06 cm, distribuídos em um delineamento em blocos ao acaso com cinco tratamentos (0,50; 1,00; 1,50; 2,00 e 2,50 indivíduos/L) e quatro repetições, em 20 tanques-rede experimentais (12 L). Foi fornecida dieta com 40,00% de proteína bruta, na proporção de 8,00% do peso vivo, duas vezes ao dia. Observou-se aumento linear da biomassa por tanque, em função da densidade de estocagem. O peso final médio e a taxa de sobrevivência apresentaram redução linear, com o aumento da densidade. Observaram-se lotes mais uniformes dos girinos cultivados em menores densidades. A conversão alimentar não foi influenciada pelas diferentes densidades de estocagem. As variáveis físico-químicas da água estiveram em níveis adequados. Concluiu-se que, com menores densidades, obtêm-se girinos maiores e lotes mais uniformes com melhor taxa de sobrevivência.Palavras-chave: densidade de estocagem, girinos, Rana catesbeiana, ranicultura, rã-touro, tanques-rede Development of Bullfrog (Rana Catesbeiana, Shaw, 1802) Tadpoles Reared at Different Stocking Densities in Net TanksABSTRACT -This research was conducted to evaluate the effect of different stocking density on the bull-frogs tadpoles development in net-pond. Three hundred and sixty animals, averaging initial weight of 0.01g and initial length of .92±.06 cm were allotted to 20 net-pond (12L) in a block randomized design with five treatments (.5, 1.0, 1.5, 2.0 and 2.5 tadpoles/L) and four replicates. The diet with 40.00% crude protein was fed twice a day at 8.00% live weight. Linear increase in biomass, as the stocking rates increased, was observed. Average final weight and the survival rate showed linear decrease, as the stocking rates increased. It was observed more uniformity groups in the lower density. Feed/gain was not affected by the different stocking rates. Physical and chemical traits had adequate levels. It was concluded that, under low stocking rates, better results of weight, uniformity of group and survival rate of the tadpoles were obtained.

RESUMO -O objetivo deste trabalho foi avaliar os efeitos da substituição da proteína do farelo de soja (FS) pela proteína do farelo de canola (FC) em dietas para alevinos de piavuçu (Leporinus macrocephalus). Um total de 288 alevinos com, em média, 0,17±0,03 g PV inicial e comprimento total inicial de 2,95±0,19 cm, foi distribuído em 24 aquários (50 L) com 12 peixes em cada em um delineamento inteiramente casualizado com seis tratamentos (0,0; 20,0; 40,0; 60,0; 80,0; e 100,0%), que correspondeu, respectivamente, a 0,00; 8,03; 16,10; 24;10; 32,15; e 43,12% de inclusão de FC nas dietas, com quatro repetições. As dietas, formuladas de modo a serem isoprotéicas, isocálcicas e isofosfóricas, foram fornecidas durante 28 dias. A taxa de eficiência protéica e a sobrevivência não foram influenciadas pelos níveis de substituição da proteína do FS pela do FC. Entretanto, foram observados efeitos lineares para porcentagem de ganho de peso, porcentagem de incremento em comprimento e custo da dieta/kg ganho e efeito quadrático dos níveis de substituição da proteína do farelo de soja sobre a conversão alimentar. A substituição de 100,00% da proteína do FS pela do FC ou a inclusão de 43,12% do FC nas dietas resultou em melhor desempenho de alevinos de piavuçu.Palavras-chave: alevinos, farelo de canola, Leporinus macrocephalus, piavuçu Partial and Total Replacement of Soybean Meal Protein by Canola Meal Protein in Piavuçu (Leporinus macrocephalus, L.) Fry DietsABSTRACT -The objective of this work was to evaluate the effects of the replacement of the protein from soybean meal (SM) by protein from canola meal (CM) in diets for piavuçu fry (Leporinus macrocephalus). Two hundred and eighty-eight fry with initial 0.17±.03 g LW and length of 2.95±.19 cm were allotted to 24 aquarium, (50-L) with 12 fish in each one. A completely randomized design with six treatments (0, 20.0, 40.0, 60.0, 80.0, and 100.0%), which corresponded to 0.0, 8.03, 16.10, 24.10, 32.15, and 43.12% of the CM inclusion in the diets and four replicates, was used. The diets, formulated to be isonitrogenous, isocalcium and isophosphoric were fed during 28 days. The protein efficiency and survival rate were not affect by the replacement levels from SM protein by CM protein. However, linear effects were observed for the percentage of weight gain, percentage of length increase and cost of the diet/kg gain and a quadratic effect of the replacement levels of protein from soybean meal on feed:gain ratio. The replacement of 100.0% of the protein from SM by CM protein or the inclusion of 43.12% of CM in the diet produced a better performance of the piavuçu fry.

RESUMO. Com o objetivo de avaliar diferentes fontes protéicas de origem vegetal para a tilápia do Nilo durante a fase de reversão sexual, foram utilizadas 360 larvas distribuídas em 24 aquários (12 litros cada) em um delineamento inteiramente casualizado com quatro tratamentos e seis repetições. Foram comparadas quatro fontes protéicas de origem vegetal, sendo o farelo de soja (FS), farelo de canola (FC), farelo de girassol (FG) e farelo de algodão (FA). A uniformidade do lote, o fator de condição e a sobrevivência não foram afetadas pelos diferentes tratamentos. O FA levou aos piores resultados no peso e no comprimento final. A matéria seca da carcaça dos peixes alimentados com FG apresentou-se superior a do FS (p<0,05). A percentagem de proteína bruta da carcaça foi mais alta nos tratamentos FC e FS, sendo que a menor percentagem foi observada no FG. Conclui-se que os farelos de soja, canola e girassol podem ser utilizados como fontes protéicas de origem vegetal sem prejudicar o desempenho das larvas de tilápia do Nilo. Palavras-chave: alimentação, fase inicial, fontes protéicas, Oreochromis niloticus, reversão sexual, tilápia do Nilo. ABSTRACT. Different protein vegetal sources for the Nile tilapia (Oreochromis niloticus L.) during sexual reversion. Three hundred and sixty Nile tilapia larvae were distributed in 24 12L-aquaria to evaluate different protein vegetal sources. Design was totally randomised with four treatments and six repetitions. Four protein vegetal sources were compared: soy meal (SM), canola meal (CM), sunflower meal (FG) and cotton meal (TM). Uniformity of lots, condition factor and survival were not affected by the different treatments. TM had the worst results in weight and final length. Carcass dry matter of fish fed on FM was superior to SM (p<0.05). Percentage of crude protein of carcass was highest in treatments CM and SM; the lowest percentage belonged to FM. SM, CM and FM may be used as protein vegetal sources without any impairment in the performance of Nile tilapia larvae.

Aim: This study uses the abundance of fish eggs and larvae to evaluate the importance of the main channel of the Paraná River and the adjacent areas of the floodplain, in the last dam-free stretch in the Brazilian territory, for the spawning and development of fish of different reproductive guilds, in order to obtain subsidies to assist in the management and conservation policies of this area, focusing on the maintenance of dam-free areas. Methods: Data were taken quarterly from August 2013 to May 2015, in 25 sites, grouped into three biotopes: main channel, tributaries and lagoons. Possible spatial variations in fish spawning and development as well as composition and structure of larvae were evaluated. Results: Higher densities of eggs were found in tributaries (Paracaí and Amambai rivers) and greater densities of larvae were observed in lagoons (Saraiva). Significant differences in composition and structure of larvae were detected only between sampling stations. As for taxonomic composition, 29 taxa were recorded, mostly non-migratory. However, long-distance migratory were also widely distributed, such as Brycon orbignyanus, Pseudoplatystoma corruscans, Prochilodus lineatus, Piaractus mesopotamicus and Rhaphiodon vulpinus, as well as invasive species Platanichthys platana and Hemiodus orthonops. In turn, Salminus brasiliensis presented low occurrence. Conclusions: This study evidenced that different species spawn in the region, mainly in tributaries, and their eggs and larvae are transported to the main channel of the Paraná River and adjacent lagoons, to complete their early development. The capture of larvae of important migratory species suggests that this environment still exhibits suitable conditions for their reproduction, mainly due to the presence of dam-free tributaries. Also, they emphasize the importance of the integrity of these environments for the maintenance of the regional fish fauna, and it is extremely important the monitoring of reproduction of the most endangered species, as well as of invasive species.

Aim: To analyze temporal distribution of larvae and juveniles and the early development and of Moenkhausia cf. gracilima. Methods: Samples were taken quarterly in twenty-five sites in the upper Paraná River floodplain between August 2013 and May 2015. The samples were taken under the water surface at night using 0.5 mm mesh plankton nets. In the laboratory, samples were sorted, identified and separated into larval (preflexion, flexion and postflexion) and juvenile periods. Results: A total of 248 individuals was collected, mainly in the Saraiva Lagoon, suggesting that the entire life cycle of this species occurs in this environment. The reproductive period takes place between December and April, since the postflexion larvae were found until May. However, the occurrence of juveniles between February and May indicates probable batch spawning. Among the 95 individuals used for ontogenic description, 82 were larvae and 13 juveniles. Larvae may be characterized by irregular pigmentation in the upper region of the head, mouth, and body, increasing throughout development; upper lobe of the caudal fin more pigmented than the lower lobe, only visible in postflexion larvae; terminal mouth; anal opening located anterior to the median region of the body and total number of myomers ranging from 34 to 40 (15 to 20 pre and 16 to 23 postanal), while juveniles have characteristics similar to adults. The total number of fin rays is: P. 11-16, V. 7-11, D, 9-11 and A. 21-23. Conclusions: According to the distribution of developmental periods it is possible to conclude that this species reproduces in the summer, preferably in lagoons. Growth analysis indicated important alterations in larval morphology (metamorphosis) that may be associated with the ecomorphological characteristics of the species. The morphological separation of larvae of M. cf. gracilima from other larvae of small characids, especially at preflexion and flexion stages may be complicated by the overlap of traits, suggesting the use of other variables, mainly morphometric, for the separation of the species.

RESUMO -Objetivando verificar a influência da substituição da proteína do farelo de soja (FS) pela proteína do farelo de canola (FC), em rações para alevinos de curimbatá, foram utilizados 120 animais com peso médio de 1,88 ± 0,82 g e comprimento total médio de 5,40 ± 0,99 cm, distribuídos em um delineamento inteiramente casualizado com seis tratamentos e quatro repetições em aquários de vidro (50 L), com cinco alevinos por unidade experimental. As rações foram formuladas para serem isoprotéicas (26,00%), isocálcicas (0,90%) e isofosfóricas (0,70%), com níveis crescentes de substituição da proteína do FS pela do FC (0,00; 20,00; 40,00; 60,00; 80,00 e 100,00%), o que correspondeu a 0,00; 8,03; 16,10; 24,10; 32,15 e 43,12% de inclusão do FC nas rações e fornecidas por um período de 30 dias. Os parâmetros físico-químicos da água foram medidos a cada sete dias. Observou-se redução linear do ganho de peso e da taxa de eficiência protéica e aumento linear da taxa de conversão alimentar, com aumento da inclusão do FC nas rações. A taxa de sobrevivência e o custo de ração/kg ganho não foram afetados com o uso do FC nas rações. Os valores da temperatura da água, do pH e da condutividade elétrica permaneceram dentro dos níveis adequados. Concluiu-se que o aumento dos níveis de inclusão da proteína do farelo de canola nas rações para alevinos de curimbatá acarretou redução no desempenho dos mesmos.Palavras-chave: Brassica napus, curimbatá, farelo de canola, farelo de soja, Prochilodus lineatus Replacement of Soybean Meal Protein by Canola Meal Protein in "Curimbatá" (Prochilodus lineatus V.) Fingerling DietsABSTRACT -The influence of the substitution of soybean meal protein (SM) by canola meal protein (CM) in Prochilodus lineatus fingerling diets was verified. One hundred and twenty specimens, averaging weight 1.88±0.82g and total length 5.40±0.99cm, was assigned to a completely randomized randomized design, with six treatments and four replicates, in a 50 L glass aquarium, with five fingerlings in each experimental unit. Isoprotein (26.00%), isocalcium (0.90%) and isophosphorus (0.70%) diets were formulated with increasing replacement levels of SM protein by CM protein (0.00, 20.00, 40.00, 60.00, 80.00, and 100.00%). Values correspond respectively to 0. 00, 8.03, 16.10, 24.10, 32.15 and 43.12% of CM inclusion in diets for 30 days. Physical and chemical parameters of water were measured every seven days. Through an increase in CM inclusion in diets, a linear decrease in weight gain and protein efficiency rate was reported; a linear increase in food conversion has also been recorded. There was no influence of CM inclusion in diets on survival rate and feed costs/kg gained. Water temperature, pH and electrical conductivity remained within proper limits. Increase in levels of protein inclusion of CM in diets for Prochilodus lineatus fingerlings caused a decrease in their performance.

Objetivou-se avaliar a seleção alimentar de organismos-alimento por formas jovens de pacu (Piaractus mesopotamicus) e curimba (Prochilodus lineatus) com diferentes idades (6, 12, 19 e 26 dias), na presença e ausência de Pistia stratiotes. Foram utilizados quatro tratamentos (T1 = pacu + P. stratiotes; T2 = pacu; T3 = curimba + P. stratiotes; T4 = curimba) e quatro repetições. A cada sete dias, foram coletadas 24 larvas de cada espécie de peixe dos tanques, sendo estas mantidas em jejum por 24 horas. Depois de distribuídas nos aquários com plâncton, as larvas permaneceram por três horas, sendo coletadas e fixadas para análise, juntamente com as amostras de água. Os tratos digestórios das larvas foram retirados e analisados sob microscópio óptico. Observaram-se diferenças estatísticas na seletividade alimentar de organismos planctônicos por larvas de mesma espécie, em diferentes idades e também entre larvas de espécies diferentes, com mesma idade, não diferindo quanto à presença ou ausência de P. stratiotes. As formas jovens de pacu e curimba selecionaram organismos similares aos seis dias de idade, passando por alterações até o 26º dia. À medida que se desenvolveram, as larvas de pacu passaram a selecionar cladóceros e ostrácodos e as de curimba, protozoários e algas.

RESUMO.O objetivo desse experimento foi determinar o nível adequado de incorporação de farinha de peixe (FP) em rações para alevinos de tilápia do Nilo, Oreochromis niloticus (Perciformes, Cichlidae) linhagem tailandesa. Foram distribuídos 300 animais com peso inicial médio de 0,42 ± 0,01 g, em 25 tanques-rede, em um delineamento em blocos casualizados com cinco tratamentos (0, 4, 8, 16 e 20% de FP na ração) e cinco repetições. Foi observado efeito quadrático (p<0,05) para o peso final médio, índice hepato-somático e conversão alimentar, com pontos de máximo em 12,15 e 15,33%, e ponto de mínimo de 18,59% de inclusão de FP, respectivamente, e aumento linear da taxa de eficiência protéica, com o aumento nos teores de FP. Não houve efeito (p>0,05) dos níveis da FP sobre a sobrevivência e rendimento de carcaça. Conclui-se que o nível adequado de inclusão de farinha de peixe em rações para alevinos de tilapia do Nilo é de 12,15%.Palavras-chave: alevinos, farinha de peixe, fontes protéicas, Oreochromis niloticus, tilápia do Nilo. ABSTRACT. Fishmeal in the diets of Nile tilapia fingerlings Oreochromis niloticus (L.), Thai strains. The adequate fishmeal (FM) inclusion level in diets forNile tilapia fingerlings, Oreochromis niloticus (Perciformes, Cichlidae) Thai strain, is provided. Three hundred fishes with initial mean average weight of 0.42 ± 0.01 g were distributed in 25 net ponds in a randomized block design with five treatments (0, 4, 8, 16 e 20% of FM in diet) and five repetitions. Quadratic effect (p<0,05) was reported for average final weight, hepatic-somatic index and feed conversion, with maximum points at 12.15 and 15.33% and minimal points at 18.59% of FM inclusion respectively, besides linear increase in protein efficiency rate with an increase in FM rates. Fish meal levels (p>0,05) did not affect survival and carcass yield. It may be concluded that the appropriate fishmeal inclusion is 12.15% in diets for Nile tilapia fingerlings.