Resumo -O objetivo deste trabalho foi avaliar o efeito da suplementação de rações, com prebiótico (mananoligossacarídeo), probiótico (Bacillus subtilis) e simbiótico, em juvenis de tambaqui (Colossoma macropomum), em duas densidades de estocagem, quanto aos parâmetros de crescimento, utilização do alimento, sobrevivência e econômicos. Um total de 192 juvenis (2,4±0,2 g) foi distribuído em 32 aquários (20 L), em delineamento inteiramente casualizado, em arranjo fatorial 2x4, com quatro repetições, durante oito semanas. Testaram-se 0,35 e 1,05 kg m -3 para a densidade de estocagem. A suplementação constituiu-se de: 2 g kg -1 de prebiótico; 2 g kg -1 de probiótico; 2 g kg -1 de prebiótico + 2 g kg -1 de probiótico; e controle. A densidade de estocagem não influenciou a sobrevivência dos peixes, embora tenha causado a redução dos parâmetros econômicos e de crescimento. A suplementação com probiótico e simbiótico aumentou o crescimento, melhorou a utilização do alimento e os parâmetros econômicos. A ração controle apresentou o menor índice de eficiência econômica, enquanto o maior índice foi obtido pelas rações suplementadas com simbiótico. Os parâmetros de crescimento, utilização do alimento e econômicos aumentaram com a suplementação com probiótico e simbiótico, em rações para juvenis de tambaqui, embora não haja efeito sinergístico entre o prebiótico e o probiótico avaliados.Termos para indexação: Bacillus subtilis, Colossoma macropomum, mananoligossacarídeo. Prebiotic, probiotic and synbiotic supplementation in diets for juvenile tambaquis at two stocking densitiesAbstract -The objective of this work was to evaluate the effect of prebiotic (mannan oligosaccharides), probiotic (Bacillus subtilis), and synbiotic diet supplementations on juvenile tambaquis (Colossoma macropomum), at two stocking densities, for growth, food utilization, survival, and economic parameters. A total of 192 juveniles (2.4±0.2 g) was distributed in 32 aquaria (20 L), in a completely randomized design, in a 2x4 factorial arrangement, with four replicates, during eight weeks. Tests were performed for 0.35 and 1.05 kg m -3 stocking density. The supplementation was constituted of: 2 g kg -1 prebiotic; 2 g kg -1 probiotic; 2 g kg -1 prebiotic + 2 g kg -1 probiotic; and a control. Stocking density had no effect on fish survival, although it decreased economic and growth parameters. Probiotic and synbiotic supplementation increased growth, and improved feed utilization and economic parameters. The control diet showed the lowest economic efficiency index, while the highest index was obtained by diets supplemented with synbiotic. Growth, food utilization, and economic parameters increased with the probiotic and synbiotic supplementation in diets for juvenile tambaquis, although there is no synergistic effect between the evaluated prebiotic and probiotic supplementations.

-This study aimed to evaluate economically the inclusion of prebiotics, probiotics and symbiotics in diets of Nile tilapia (4.07 ± 0.30 g), at two stocking densities (0.6 and 1.2 kg m -3 ). A total of 288 fish were distributed over 32 tanks (40 L) in a completely randomised design, in a 2 x 4 factorial (stocking density x additives), with four replications, over six weeks. The following were evaluated: total feed consumption (FC), final biomass (FB), relative gain in biomass (RGB), apparent feed conversion (AFC), survival rate (SUR), average cost of feed per kg of live weight gain (ACF), total cost of feed (TCF), total cost of production (TCP), gross income (GI), operating profit (OP) and economic efficiency index (EEI). No effect was seen on the evaluated parameters from the interaction (p>0.05) between stocking density and inclusion of the feed additives. No influence was observed (p>0.05) on SUR from the stocking density, although this significantly influenced the parameters FB, FC, RGB, AFC, ACF, TCF, TCP, GI and OP. There was no significant influence from the inclusion of prebiotics, probiotics and symbiotics on FC, SUR and TCF, however there was an influence (p<0.05) on the parameters FB, RGB, AFC, ACF, TCP, GI and OP. The control diet at the higher density displayed the worst EEI. The best EEI was obtained by fish at the lower density which received feed with added probiotics and symbiotics. The best indices of economic and zootechnical performance obtained demonstrate the economic viability of including prebiotics, probiotics and symbiotics in the diets of Nile tilapia.

Dwarf rainbowfish (Melanotaenia praecox) are an ornamental fish with a high added value and considerable commercial interest. However, little information is known about the organism's reproductive biology, especially the early stages of embryonic development (initial ontogeny). Melanotaenia praecox embryos were examined throughout development to describe the dwarf rainbowfish initial ontogeny. Eggs were incubated at 28°C, and observations were recorded at pre-determined times. Development stages were identified and classified according to morphophysiological characteristics. The initial size of the eggs ranged between 0.99 and 1.04 mm. Oil droplets were observed in the eggs, and fixing filaments for adhesion were observed in the corium. Embryonic development was similar to that of other species in the genus Melanotaenia, in which hatching begins 119.50 h post-fertilisation or 3405.75 degree-h post-fertilisation. The main features of the newly hatched larvae were excellent swimming activity, a reduced yolk sac, mouth movement and an apparently functional digestive system.

A six week study was conducted to investigate the supplementation of prebiotic (Mannan oligosaccharide-MOS, from yeast Saccharomyces cerevisiae), probiotic (Bacillus subtilis-BS, C-3102 strain) and their combination in diets for Nile tilapia. 192 fishes (4.03 ± 0.28 g) were distributed into 16 tanks (40-L), in a completely randomized design (n=4). The following treatments were evaluated: control; prebiotic-2 g MOS kg-1 ; probiotic-2 g BS kg-1 and synbiotic-1 g MOS kg-1 plus 1 g BS kg-1. Fishes fed diets pre-, pro-and synbiotic supplemented performed better in average daily gain, feed conversion rate, specific growth rate, protein efficiency ratio, carcass yield, total and standard length and body height than those maintained on control diets. The probiotic supplementation resulted in higher villus height and intestinal perimeter ratio than the control diet while the pre-and synbiotic supplementation in diets resulted in higher intestinal perimeter ratio. Carcass protein and ether extract were, respectively, higher and lower in fish fed synbiotic diets than other fish. The results of this study indicated that the mannan oligosaccharide and Bacillus subtilis supplementation, isolated or combined (synbiotic), could improve growth, body index, intestine morphometry and carcass composition in Nile tilapia.

This study aimed to evaluate the effects of the co-feeding period (C) on the survival and growth of larvae of nishikigoi Cyprinus carpio, during the weaning period from live to inert food. A total of 1680 larvae with initial weight of 1.33 ± 0.12mg and initial length of 6.0 ± 0.33mm were used. The inert diet used was a commercial ration with 55% crude protein and the live food was the newly hatched nauplii of Artemia franciscana. The experiment was conducted following a completely randomized design with six treatments and four replications. Treatments constituted of: a) LF = supply of live food throughout the experimental period; b) C4 = 6 days of live food + 4 days of co-feeding (inert diet and live food) + 16 days of inert diet; c) C8 = 6 days of live food + 8 days of co-feeding + 12 days of inert diet; d) C12 = 6 days of live food + 12 days of co-feeding + 8 days of inert diet; e) IF = supply with inert diet throughout the experimental period; and f) F = fasting. Our results showed that the co-feeding period influences the survival and growth of the larvae. Survival in the treatment with the longest cofeeding period showed an improvement of over 70% when compared to the shortest period. Further, we noted a doubling of the juvenile weight after 26 days of age. There was a quadratic effect for all parameters, with maximum points ranging between 19.4 and 22.6 days of supply of live food. We concluded that the supply of commercial feed as exclusive food is unworkable in nishikigoi larviculture. RESUMO:Com o objetivo de avaliar os efeitos do período de co-alimentação (C) na sobrevivência e crescimento de larvas de nishikigoi Cyprinus carpio, durante o período de transição de alimentos vivos (AV) para dieta inerte (DI), foram utilizados um total de 1680 larvas com peso inicial de 1,33 ± 0,12mg e comprimento inicial de 6,0 ± 0,33mm. Para a dieta inerte foi utilizada uma ração comercial com 55% de proteína bruta e como alimento vivo, nauplios recém eclodidos de Artemia franciscana. O experimento foi conduzido em delineamento inteiramente casualizado com seis tratamentos e quatro repetições. Os tratamentos foram constituídos por: LF = suprimento de alimento vivo ao longo de todo período experimental; C4 = 6 dias de alimento vivo + 4 dias de co-alimentação (dieta inerte e alimento vivo) + 16 dias de dieta inerte; C8 = 6 dias de alimento vivo + 8 dias de co-alimentação + 12 dias de dieta inerte; C12 = 6 dias de alimento vivo + 12 dias de co-alimentação + 8 dias de dieta inerte; ID = dieta inerte durante todo o período experimental, J = jejum. O período de co-alimentação influencia a sobrevivência e o crescimento das larvas melhorando mais de 70% a sobrevida entre os períodos de co-alimentação mais longos e curtos testados. Além disso, foi verificado um aumento de duas vezes o peso juvenil após 26 dias de idade. Houve um efeito quadrático para todos os parâmetros, com pontos máximos variando entre 19,4 e 22,6 dias de suprimento de alimentos vivos. Também é possível concluir que o fornecimento de alimentação comercial, com...

RESUMOConduziu-se um experimento com o objetivo de avaliar a influência do período de coalimentação na sobrevivência e no crescimento de larvas de Betta splendens. As larvas foram alimentadas com náuplios de Artemia durante sete dias e, posteriormente, submetidas aos seguintes tratamentos: jejum contínuo; ração contínua; quatro dias de coalimentação + 14 dias de ração; oito dias de coalimentação + 10 dias de ração; 12 dias de coalimentação + seis dias de ração; náuplios de Artemia durante todo o período experimental. Os valores das variáveis de desempenho das larvas do tratamento 12 dias de coalimentação + seis dias de ração e do tratamento náuplios de Artemia foram superiores aos demais tratamentos, exceto para sobrevivência, em que não houve diferença significativa com o tratamento oito dias de coalimentação + 10 dias de ração. Considerando-se apenas o tempo de oferta de Artemia (em dias), obteve-se a equação de regressão para as variáveis analisadas. A sobrevivência e a taxa de crescimento específico (TCE) apresentaram efeito quadrático, e as demais variáveis apresentaram efeito linear. O ponto de máxima para sobrevivência foi de 21,7 dias (88,92%) e para TCE foi de 26,2 dias (23,47% dia -1 ). O período de co-feeding influencia no crescimento e na sobrevivência de larvas de Betta splendens. Após o período de 19 dias de oferta de alimento vivo, com 12 dias de coalimentação, as larvas estão aptas a aproveitar de maneira eficiente o alimento inerte sem prejuízos ao crescimento e à sobrevivência.Palavras-chave: peixes ornamentais, Betta splendens, larvicultura de peixes, coalimentação, transição alimentar ABSTRACT An experiment was carried out to evaluate the influence of the period of co-feeding on survival and growth of Betta splendens larvae. The following strategies for co-feeding were used: continuous fasting, 18 days of inert diet, 4 days of co-feeding + 14 days of inert diet; 8 days of co-feeding + 10 days of inert diet; 12 days of co-feeding + 6 days of inert diet, nauplii of Artemia throughout the experiment period. The values of performance variables for larvae with 12 days of treatment for co-feeding + 6 days of inert diet and the nauplii treatment with

The aim of this study was to describe the embryonic and larval development of discus fish (Symphysodon aequifasciatus), and to determine the time required, hours post fertilization (hpf), for the emergence of various structures. To describe embryonic and larval stages, observations were made at regular periods under an optical microscope and images were taken with a digital camera attached to a microscope. The average temperature reached in the experimental tank was 27.9°C. Important facts in embryonic and larval development are described, such as the closure of the blastopore, which occurred at 31.5 hpf; a period of eruption, which occurred at 58.5 hpf; and a mouth opening, which occurred at 90.5 hpf; and larvae that exhibited oriented swimming and eating exogenous food at 136.5 hpf.

The blue discus (Symphysodon aequifasciatus) is often sold for ornamental purposes. It is a neotropical cichlid from South America, which is native to the rivers of the Amazon basin of Brazil, Peru and Colombia. The purpose of this study was to characterize the reproductive behavior of S. aequifasciatus and identify features that can later be used by breeders to facilitate the handling and reproduction of this species in captivity. The experiment was divided into two stages: the first dealt with partner selection and couple formation to observe the behaviors of territoriality, pursuing, fleeing, biting, stay, protecting and cleaning of the substrate. The second stage documented mating behavior, nesting and parental care, to observe vibration, spawning, permanence with the offspring, aeration of eggs, cleaning of spawning, color change and shift-taking in parental care. The results of the study allowed identifying disputes for and establishment of territory, as well as the selection and cleaning of the substrate for spawning performed by both sexes. The parental care was observed from spawning in the substrate until the care for the larvae. It was found that the reproductive success of this species is closely linked to biparental care observed during the entire reproductive process and early stages of the hatchings. KEYWORDS: Amazonian Fish, Ornamental Fish, Larviculture, Reproduction, Behavior Descrição do comportamento reprodutivo de Symphysodon equifasciatus (Cichlidae) em cativeiro RESUMO Dentre as espécies de ciclídeos neotropicais comercializados para ornamentação, destaca-se o acará-disco (Symphysodon aequifasciatus), que é um ciclídeo neotropical originário da América do Sul, pertencente aos rios da bacia Amazônica do Brasil, Peru e Colômbia. Este estudo caracteriza o comportamento reprodutivo do acará disco (S. aequifasciatus) identificando características que posteriormente possam ser identificadas por criadores e utilizadas para facilitar o manejo e reprodução desta espécie em cativeiro. O experimento foi dividido em duas etapas, a primeira com a escolha de parceiro e formação do casal, e a segunda com acasalamento, desova e cuidado parental. Na primeira etapa foram observados os comportamentos de territorialidade, perseguição, fuga, mordida, permanência, proteção e limpeza do substrato, enquanto que na segunda etapa os comportamentos observados nesta etapa foram: tremor, desova, permanência com a prole, aeração dos ovos, limpeza da desova, mudança de coloração e revezamento do cuidado parental. Como resultado foi possível constatar disputa e estabelecimento de território, bem como a seleção e limpeza do substrato para a desova realizada por ambos os sexos. O cuidado parental foi observado desde a desova no substrato até o cuidado com as larvas e o sucesso reprodutivo desta espécie está intimamente ligado ao cuidado biparental observado por durante todo o processo reprodutivo e estágio inicial dos filhotes.