Effects of peptides and probiotics supplementation via diet on blood parameters and growth performance of Piaractus brachypomus during the growth-out phase.

Background: There is no evidence of peptides-probiotics symbiosis as supplements in aquafeeds. Aim: To evaluate the effect of peptides and probiotics supplementation via diet on blood parameters and growth performance of juvenile Piaractus brachypomus, an Amazonian fish, during the growth-out phase. Methods: 120 juvenile P. brachypomus (242.77 g) were placed into twelve 200-l tanks (10 fish/tank), housed in an indoor open system with constant water renovation (flow rate:1.50 l/minute). The experiment used a completely randomized design with a 4 × 5 factorial arrangement [4 doses of supplementation (CD: commercial diet; PepD: CD+1.50% of peptides per CD weight; ProD: CD+40.00 ml of activated probiotics per kg of diet (Lactobacillus spp., Rhodopseudomonas spp., Saccharomycetes spp.); PepProD: CD+Pep+Pro); 5 sampling times (zero, second, fourth, sixth, and eighth week); n = 3]. Fish were fed twice a day at a feeding rate of 1% of body weight. At each sampling time, blood was collected and fish were measured for growth performance analysis. Data were analyzed by using two-way ANOVA and Tukey's test (p < 0.05). Results: The values of hematocrit (18.31%), leukocytes (1,216.67 mm3), neutrophils (81.27%), lymphocytes (18.73%), albumin (1.08 g/dl), relative growth rate (1.002%/day), and the Fulton allometric condition factor (2.03) remained constant throughout the experiment (p > 0.05). Plasma glucose decreased for all fish in the second week (59.56 mg/dl); then, that level increased in fish fed with the CD (89.00 mg/dl), while fish fed with PepD, ProD, and PepProD showed constant values (57.22 mg/dl). The plasma protein levels were constant in fish fed with the PepD and PepProD, (p > 0.05), while fish fed with the CD and ProD showed non-constant and higher values. At the end of the trial, fish fed with the PepProD showed the highest weight gain and the lowest feed conversion rate (39.66 g; 0.97). Conclusion: It is possible to maintain the stability of plasma glucose and plasma protein by supplementing diets with peptides, but the peptides-probiotics symbiosis administrated via diet contributes to maintaining the stability of plasma glucose and plasma protein and to improve the growth performance of juvenile P. brachypomus during the growth-out phase.

Niveles de pH gastrointestinal posprandial en juveniles de Piaractus brachypomus (Serrasalmidae) y Schizodon fasciatus (Anostomidae) / Postprandial gastrointestinal pH levels in juveniles of Piaractus brachypomus (Serrasalmidae) and Schizodon fasciatus (Anostomidae)

RESUMEN Se realizó un estudio comparativo para determinar variaciones del pH gastrointestinal posprandial en juveniles de Piaractus brachypomus (n = 21) y Schizodon fasciatus (n = 21) en condiciones de cultivo. Previo ayuno de 24 horas, los peces fueron alimentados tres veces al día a saciedad aparente, empleando una dieta mixta, conformada por alimento balanceado y músculo de corazón de pollo (proporción 1:1). La estimación del pH en el estómago, en la porción anterior y en la porción media del intestino se realizó antes de la alimentación y ocho horas posprandial, utilizando un electrodo de pH con punta tipo lanza. Se observaron diferencias significativas (p < 0,05) de los valores de pH en el estómago y en la porción media del intestino, según el tiempo de digestión en ambas especies; mientras que, en la porción anterior del intestino, solo S. fasciatus mostró diferencias significativas (p < 0,05). En ambas especies se observó un incremento del pH estomacal a la primera hora posprandial (2,39 a 4,78 en P. brachypomus, 4,47 a 4,73 en S. fasciatus), motivado por el efecto del alimento ingerido y con una reducción de los valores al finalizar el experimento. Durante las horas de evaluación, los valores de pH intestinal para P. brachypomus y S. fasciatus estuvieron entre 6,68 y 7,47 y 6,86 y 7,60, respectivamente, aumentando de manera distal a lo largo del intestino. Se concluye que ambas especies presentan una acidificación estomacal permanente, mientras que la porción anterior y media del intestino mantienen un pH ligeramente neutro durante la digestión y asimilación del alimento.

ABSTRACT A comparative study to determine variations in postprandial pH values along the gastrointestinal tract was performed among juveniles of Piaractus brachypomus (n = 21) and Schizodon fasciatus (n = 21) in rearing conditions. After fasting for 24 hours, the fish were fed three times a day to apparent satiety, with a mixed diet containing pelleted balanced food and chicken heart muscle (ratio 1:1). The evaluation was made before feeding and postprandial (eight hours), where the pH values of the stomach, in the anterior and in the middle portions of the intestine were estimated, using a pH electrode with a lancetype tip. Significant differences (p < 0.05) at the stomach and the middle portions of the intestine, according to the digestion time were observed in both species, while at the anterior portions of the intestine, only S. fasciatus showed significant differences (p < 0.05). In both species, an increase in stomach pH was observed in the first postprandial hour (2,39 to 4,78 in P. brachypomus, 4,47 to 4,73 in S. fasciatus), led by the effect of the ingested food, and the pH values were reduced at the end of the experiment. During the evaluation hours, intestinal pH values for P. brachypomus and S. fasciatus were between 6,68 and 7,47 and 6,86 and 7,60, respectively, increasing distally along the intestine. It is concluded that both species present a permanent stomach acidification, and that the anterior and middle portions of the intestine maintain a slightly neutral pH during digestion and assimilation of food.

Changes in sperm motility of amazonian fish Tambaqui Colossoma macropomum (Cuvier 1816) (Characiformes: Serrasalmidae) exposed to two pesticides / Alterações na motilidade espermática do peixe amazônico Tambaqui Colossoma macropomum (Cuvier 1816) (Characiformes: Serrasalmidae) exposto a dois pesticidas

Abstract The great biodiversity of neotropical fish species that have external fertilization as a reproductive strategy, like the tambaqui, requires more careful analyzes in toxicological tests of the various pesticides implemented in Brazilian agriculture over the last few years. In this context, the objective of the present work was to evaluate possible sperm alterations in tambaqui (Colossoma macropomum) semen exposed to two different pesticide residues. Seminal samples of sexually mature tambaqui males from a local fish farm were used. Semen was collected eight hours after hormone induction into graduated glass tubes. After initial assessment of the lack of prior activation, the experiment was carried out in a factorial scheme, testing two pesticides widely used in agricultural systems (glyphosate and fenitrothion). For each pesticide, five concentrations were tested (6, 12, 24, 120 and 240 mg/L), with motility analysis at times 0, 30 and 60 seconds after activation. As a control, activation with 0.9% NaCl solution and motility analysis at the same times described for pesticides were used. Results indicate that in natura samples exhibited initial motility of 89.2 ± 4.9% and mean duration of 100 seconds (up to 10% sperm motility). The reduction in sperm motility occurred significantly (p < 0.05) after 30 seconds in all concentrations tested, except for the concentration of 240 mg/L because no activation was observed. The tests described here demonstrate that tambaqui semen was sensitive to the process of exposure to pesticide residues, and can be used in biomonitoring analyzes of the aforementioned agricultural pesticides.

Resumo A grande biodiversidade das espécies de peixes neotropicais que possuem a fertilização externa como estratégia reprodutiva, a exemplo do tambaqui, exige análises mais criteriosas em testes toxicológicos dos diversos defensivos agrícolas implementados na agricultura brasileira ao longo dos últimos anos. Nesse contexto, o objetivo do presente trabalho foi avaliar possíveis alterações espermáticas no sêmen de tambaqui (Colossoma macropomum) exposto a resíduos de dois diferentes pesticidas. Foram utilizadas amostras seminais de machos de tambaqui sexualmente maduros provenientes de uma piscicultura local. O sêmen foi coletado oito horas pós indução hormonal em tubos de vidro graduados. Após avaliação inicial de inexistência de ativação prévia, foi realizado o experimento em esquema fatorial, sendo testados dois pesticidas muito utilizados em sistemas agrícolas (glifosato e fenitrotiona). Para cada pesticida foram testadas cinco concentrações (6, 12, 24, 120 e 240 mg/L), com análise da motilidade nos tempos 0, 30 e 60 segundos pós ativação. Como controle, foi utilizada a ativação com solução de NaCl a 0,9% e análise da motilidade nos mesmos tempos descritos para os pesticidas. Resultados indicam que as amostras in natura exibiram motilidade inicial de 89,2 ± 4,9% e tempo de duração médio de 100 segundos (até 10% de motilidade espermática). A redução da motilidade espermática ocorreu de forma significativa (p < 0,05) após 30 segundos em todas as concentrações testadas, exceto na concentração de 240 mg/L por não ter sido observada ativação. Os testes aqui descritos demonstram que o sêmen de tambaqui se mostrou sensível ao processo de exposição aos resíduos de pesticidas, podendo ser utilizado em análises de biomonitoramento dos referidos defensivos agrícolas.

Morphological and functional structure of two Ergasilidae parasites determine their microhabitat affinity on the gills of an Anostomidae fish from the Amazon.

The aim of this study was to investigate the microhabitat affinities of Ergasilus sp. and Therodamas longicollum on the gills of Leporinus fasciatus ("aracu-piau"), an anostomid fish from the Amazon. A total of 143 specimens of L. fasciatus were examined, of which 35% had their gills parasitized by at least one ergasilid species. A total of 159 specimens of Ergasilus sp. and 97 specimens of T. longicollum were recovered. Both ergasilids species exhibited a greater affinity for attachment in arch 1 of the gills of the host. There was a negative correlation between the abundance of Ergasilus sp. and the abundance of T. longicollum within each gill arch. Analysis of distribution along the gill arch showed a higher occurrence of Ergasilus sp. in Section 5, while T. longicollum occurred mainly in Section 3 of the gills. There was a positive correlation between the abundance of these ectoparasites and the size of the gill arch. Ergasilus sp. occurred only on the filament of the gill arch and exhibited affinity for the proximal region, while T. longicollum occurred only in the gill arch itself. The results reveal that these two parasite species compete in the gills of the host without the overlapping of their niches.

Dietary lysine requirements of Colossoma macropomum (Cuvier, 1818) based on growth performance, hepatic and intestinal morphohistology and hematology.

This study aimed to determine the dietary lysine requirements of juvenile Colossoma macropomum tambaqui based growth performance, hepatic and intestinal morphohistology and hematology. Tambaqui were fed with levels of 6.60, 9.72, 12.84, 15.96, 19.08, and 22.20 g/kg of total lysine and those who received 15.96 g/kg dietary lysine showed higher final weight (p= 0.001) and optimized feed conversion ratio (p= 0.001). Morphohistological modifications (presence of fat droplets) were present in livers of fish fed with low levels of lysine. In the morphohistology of the intestine, the diets influenced the density of the intestinal, cell layers, height and perimeters of the villi and acid mucin secretion by the goblet cells. In the proximal intestine, mucosa layer density was greater at the level of 15.96 g/kg (p= 0.001). In the middle intestine, height (p= 0.001) and perimeter (p= 0.001) of the villi were greater at low levels of lysine (respectively, 9.72 and 12.84 g/kg dietary lysine). No differences were found for the hemoglobin, hematocrit, erythrocytes, MCV, MCH, MCHC, thrombocytes and leukocytes differentiated of fish fed with experimental diets (p>0.05). The biochemical responses were affected by the diet, both in plasma concentration (protein and cholesterol; p<0.05), and in muscle (ash and moisture; p<0.05). In conclusion, the dietary requirement for lysine for tambaqui juveniles was estimated to be 15.4 - 15.6 g/kg of diet (5.7% -5.8% dietary protein).

Subfamily hypostominae: similarities and differences in testicular structure of amazonian fish.

BACKGROUND: Hypostominae is a subfamily of the family Loricariidae that has a great diversity of species. Accordingly, testicular studies in fish can contribute to the phylogeny and taxonomy of species and to the comparison of reproductive aspects between species. Thus, this work aimed to characterize the testicular morphology and spermatogenesis of the Hypostominae species Baryancistrus xanthellus, Peckoltia oligospila and Hypancistrus zebra. RESULTS: B. xanthellus, P. oligospila and H. zebra had an anastomosed tubular type of testis. The germinal epithelium was continuous with unrestricted spermatogonia, and the proliferative, meiotic and spermiogenic phases were defined in all species. In the spermiogenic phase, spermatids were classified as initial, intermediate and final. Only in B. xanthellus in the final phase was there nuclear rotation. The sperm for the three species had a head with an oval shape and a single flagellum composed of the short midpiece, principal piece and end piece. B. xanthellus and P. oligospila showed a cylindrical flagellum and H. zebra showed projections that produced a flattened appearance. CONCLUSIONS: On the basis testicular structure and ultrastructural characteristics of the germ cells, there was a greater relationship between B. xanthelus and P. oligospila, while H. zebra had particular characteristics. These aspects show that despite belonging to the same subfamily, the species have distinct biological characteristics.

Consequences of oxidative damage on the fatty acid profile in muscle of Cichlasoma amazonarum acutely exposed to copper.

Rapid industrialization results in the production of large quantities of waste that are commonly discharged into water bodies, leading to the damage of the aquatic ecosystem and freshwater organisms. Copper (Cu) can induce oxidative damage in fish muscle, the main fish portion that is consumed by humans. However, the responses of the Amazon fish Cichlasoma amazonarum and its capacity to withstand acute Cu concentrations found in Amazon water around mines remain unknown. Thus, the aim of this study was to evaluate whether exposure to Cu causes muscle oxidative stress and/or oxidative damage and impairs the fillet fatty acid profile of C. amazonarum acutely exposed to Cu found in Amazon waters around mines. Muscle reactive oxygen species and protein carbonylation levels were significantly higher in fish exposed to 1500 µg/L Cu compared with the control group, while muscle lipid peroxidation levels were significantly higher in fish exposed to 500, 750, and 1500 µg/L Cu compared with control group. Muscle antioxidant capacity against peroxyl radical's levels and glutathione peroxidase activity were significantly lower in fish exposed to 1500 µg/L Cu compared with the control group, while muscle superoxide dismutase activity was significantly lower in fish exposed to 750 and 1500 µg/L Cu compared with control group. The total content of saturated fatty acids was significantly higher in fish exposed to 1500 µg/L Cu compared with the control group, while the total content of monounsaturated fatty acids and sum of n3 fatty acids were significantly lower in fish exposed to 1500 µg/L Cu compared with control group. No significant difference was observed regarding muscle catalase, glutathione S-transferase, and glutathione reductase activities. Based on these lines of evidence, the results of this comprehensive study agree with the initial hypothesis that the exposure to Cu found in Amazon water around mines induces oxidative damage and inhibits enzymatic and non-enzymatic antioxidant response in the muscle of C. amazonarum exposed to high Cu levels. Moreover, the impairment of the fillet fatty acid profile appears to be mediated by oxidative damage, representing a negative impact on fish health.

Dietary garlic essential oil on development parameters of severum post-larvae / Óleo essencial de alho sobre os parâmetros de desenvolvimento de pós-larvas de acará severo

The present study aimed to evaluate the influence of garlic essential oil (GEO) on the growth performance and morphometric variables of severum (Heros severus) post-larvae. A growth trial was performed using 150 severum post-larvae (1.6 ± 0.03 mg and 5.58 ± 0.1 mm), distributed in fifteen 1-L aquaria, with constant aeration. The fish were essayed in a completely randomized design with five treatments, using diets containing graded levels of GEO (0.00, 0.05, 0.50, 1.00 and 1.50 g kg-1) and three replicates. The diets were offered four times a day, until apparent satiation, for 30 days. At the end of the experiment, the fish were counted, weighed and measured, to evaluate growth performance and morphometric variables. Increased diet levels of GEO resulted in a linear reduction in growth performance parameters, except for the survival rate, weight and length uniformity of the batch, and morphometric variables which did not present significant differences. Elevated concentrations of dietary GEO may be detrimental to larvae and post-larvae of fish, which could be more sensitive to the potential damage that high concentrations of this essential oil may cause. Therefore, the inclusion of GEO in levels above 0.05 g kg-1 in diets for severum post-larvae is not recommended.(AU)

O presente estudo teve como objetivo avaliar a influência do óleo essencial de alho (OEA) sobre o desempenho produtivo e as variáveis morfométricas de pós-larvas de acará severo (Heros severus). Foi realizado ensaio de crescimento com 150 pós-larvas severas (1,6 ± 0,03 mg e 5,58 ± 0,1 mm), distribuídas em quinze aquários de 1 L, com aeração constante. Os peixes foram distribuídos em delineamento inteiramente casualizado com cinco tratamentos, dietas contendo diferentes níveis de OEA (0,00; 0,05; 0,50; 1,00 e 1,50 g kg-1) e três repetições. As dietas foram oferecidas quatro vezes ao dia, até saciedade aparente, por 30 dias. Ao final do experimento, os peixes foram contados, pesados e medidos, para avaliação do desempenho produtivo e das variáveis morfométricas. O aumento dos níveis de OEA na dieta resultou em redução linear nos parâmetros de desempenho produtivo, com exceção da taxa de sobrevivência e uniformidade de peso e comprimento do lote, que não apresentaram diferenças significativas, assim como as variáveis morfométricas. Concentrações elevadas de OEA na dieta podem ser prejudiciais para larvas e pós-larvas de peixes, que podem ser mais sensíveis ao dano potencial que altas concentrações deste óleo essencial podem causar. Portanto, a inclusão de OEA em níveis acima de 0,05 g kg-1 em dietas para pós-larvas de acará severo não é recomendada.(AU)

Seminal characterization of the Amazonian fire-eye tetra Moenkhausia oligolepis (Günther, 1864).

The seminal characteristics of Moenkhausia oligolepis are described. Three males were induced with a single dose of carp pituitary. Semen was collected 6 h after induction, and diluted in dibasic sodium phosphate extender solution. For motility analysis, 1 µl of diluted semen was added to 10 µl of distilled water to achieve gamete activation. The average duration of total motility was 76.67 s; while the average sperm motility rate at intervals of 15 s was 95.3, 85.3, 59.6, 31.7, 13.0, 4.6 and 1.2%. To determine sperm concentration in samples, 0.5 µl of semen was diluted with 500 µl of glutaraldehyde. An aliquot of 10 µl of this dilution was utilized for cell counting. An average count of 4.97 × 109 ± 3.46 sperm/ml was obtained. Morphological analyses were performed using eosin-nigrosine dye; 20.33% of the sperm were observed to be dead. Live sperm, comprising the other 79.67%, had an average length of approximately 30 µm, with a head diameter of 4.488 ± 0.7 µm; and a flagella plus mid-piece length of 26.071 ± 12.4 µm. Of those sperm, 69% had a normal morphology, while 31% had primary and secondary abnormalities. The observed abnormality rate did not have a detrimental effect on artificial fertilization potential for the species. The description of the seminal characteristics of a species is one of the most important sets of information required for artificial reproduction of fish in captivity. It also contributes significantly to the total biological knowledge of the studied species.

Dietary garlic essential oil on development parameters of severum post-larvae / Óleo essencial de alho sobre os parâmetros de desenvolvimento de pós-larvas de acará severo

The present study aimed to evaluate the influence of garlic essential oil (GEO) on the growth performance and morphometric variables of severum (Heros severus) post-larvae. A growth trial was performed using 150 severum post-larvae (1.6 ± 0.03 mg and 5.58 ± 0.1 mm), distributed in fifteen 1-L aquaria, with constant aeration. The fish were essayed in a completely randomized design with five treatments, using diets containing graded levels of GEO (0.00, 0.05, 0.50, 1.00 and 1.50 g kg-1) and three replicates. The diets were offered four times a day, until apparent satiation, for 30 days. At the end of the experiment, the fish were counted, weighed and measured, to evaluate growth performance and morphometric variables. Increased diet levels of GEO resulted in a linear reduction in growth performance parameters, except for the survival rate, weight and length uniformity of the batch, and morphometric variables which did not present significant differences. Elevated concentrations of dietary GEO may be detrimental to larvae and post-larvae of fish, which could be more sensitive to the potential damage that high concentrations of this essential oil may cause. Therefore, the inclusion of GEO in levels above 0.05 g kg-1 in diets for severum post-larvae is not recommended.

O presente estudo teve como objetivo avaliar a influência do óleo essencial de alho (OEA) sobre o desempenho produtivo e as variáveis morfométricas de pós-larvas de acará severo (Heros severus). Foi realizado ensaio de crescimento com 150 pós-larvas severas (1,6 ± 0,03 mg e 5,58 ± 0,1 mm), distribuídas em quinze aquários de 1 L, com aeração constante. Os peixes foram distribuídos em delineamento inteiramente casualizado com cinco tratamentos, dietas contendo diferentes níveis de OEA (0,00; 0,05; 0,50; 1,00 e 1,50 g kg-1) e três repetições. As dietas foram oferecidas quatro vezes ao dia, até saciedade aparente, por 30 dias. Ao final do experimento, os peixes foram contados, pesados e medidos, para avaliação do desempenho produtivo e das variáveis morfométricas. O aumento dos níveis de OEA na dieta resultou em redução linear nos parâmetros de desempenho produtivo, com exceção da taxa de sobrevivência e uniformidade de peso e comprimento do lote, que não apresentaram diferenças significativas, assim como as variáveis morfométricas. Concentrações elevadas de OEA na dieta podem ser prejudiciais para larvas e pós-larvas de peixes, que podem ser mais sensíveis ao dano potencial que altas concentrações deste óleo essencial podem causar. Portanto, a inclusão de OEA em níveis acima de 0,05 g kg-1 em dietas para pós-larvas de acará severo não é recomendada.

Ichthyofauna from floodplain lakes of Reserva de Desenvolvimento Sustentável Piagaçu-Purus (RDS-PP), lower rio Purus / Ictiofauna de lagos de várzea da Reserva de Desenvolvimento Sustentável Piagaçu-Purus (RDS-PP), baixo rio Purus

Abstract: The ichthyofauna of the rio Purus has been little investigated, especially in its lower portion, characterized by diverse aquatic environments, especially in flooded areas. We inventoried the ichthyofauna of floodplain lakes with different management efforts in Reserva de Desenvolvimento Sustentável Piagaçu-Purus (RDS-PP), which represent important resource for commercial fishing in North region, in the first illustrated inventory of the fish fauna from lower rio Purus. We surveyed 20 lakes, classified as open access (eight lakes) and protected (12 lakes) during 2009 low water levels. A total of 2,299 individuals were collected, represented by seven orders, 25 families and 74 species. Characiformes was the most representative order in number of species and families, followed by Siluriformes, Cichliformes, Gymnotiformes, Clupeiformes, and Osteoglossiformes. Most abundant and frequent species were Pygocentrus nattereri, Triportheus angulatus, Serrasalmus sp. "2n=58", Pterygoplichthys gibbiceps, and Osteoglossum bicirrhosum. Protected lakes presented higher species richness compared to open access lakes. Similarly, protected lakes possessed 26 species occurring exclusively, with emphasis on Colossoma macropomum, an important species for fisheries due to its commercial importance. We added 44 new records of fish species for the lower rio Purus. Our results indicate the potential efficiency of zoning systems of open access and protected lakes established by local population and ruled by RDS-PP for fisheries management. Therefore, we strongly suggest its maintenance for conservation of ichthyofauna of floodplain lakes of lower rio Purus.

Resumo: A ictiofauna do rio Purus tem sido pouco investigada, especialmente em seu curso inferior, caracterizada pela diversidade de ambientes aquáticos, especialmente em áreas de inundação. Inventariamos a ictiofauna dos lagos de várzea com diferentes tipos de manejo na Reserva de Desenvolvimento Sustentável Piagaçu-Purus (RDS-PP), que representa importante recurso para pesca commercial na região Norte, no primeiro inventário ilustrado da fauna de peixes do baixo rio Purus. Amostramos 20 lagos classificados como de uso (oito lagos) e proteção (12 lagos), durante o período de águas baixas de 2009. Foi coletado um total de 2.299 indivíduos representados por sete ordens, 25 famílias e 74 espécies. Characiformes foi a ordem mais representativa em número de espécies e famílias, seguida por Siluriformes, Cichliformes, Gymnotiformes, Clupeiformes e Osteoglossiformes. As espécies mais abundantes e frequentes foram Pygocentrus nattereri, Triportheus angulatus, Serrasalmus sp. "2n=58", Pterygoplichthys gibbiceps e Osteoglossum bicirrhosum. Lagos de proteção apresentaram maior riqueza de espécies comparados aos lagos de uso. Similarmente, lagos de proteção possuíam 26 espécies ocorrendo exclusivamente nesta categoria, com ênfase no Colossoma macropomum, uma espécie importante para pesca devido ao seu valor comercial. Adicionamos 44 novos registros de espécies de peixes para o baixo rio Purus. Nossos resultados indicam a potencial eficácia do sistema de zoneamento de lagos de uso e proteção para o manejo da pesca estabelecido pela população local e regulamentada pela RDS-PP. Portanto, sugerimos fortemente sua manutenção para conservação da ictiofauna dos lagos de várzea do baixo rio Purus.

Trypan blue staining is not efficient in determining oocyte viability in Colossoma macropomum and Brycon amazonicus / Coloração com azul de tripan não é eficiente na determinação da viabilidade de oócitos em Colossoma macropomum e Brycon amazonicus

Currently, there is no effective technique to evaluate the quality of oocytes in fish farming in apractical and affordable way. The cell membrane integrity test with the vital dye trypan blue (TB)could be an option. In this study, Colossoma macropomum and Brycon amazonicus oocytes were exposed to different TB concentrations seeking to verify a possible relationship between the results of staining tests and reproductive rates. Oocytes were exposed to concentrations of 0.05, 0.04, 0.03, 0.02 and 0.01% TB for 1 minute and subsequently were evaluated under a stereomicroscope. The percentage of unstained (viable) oocytes from each sample was correlated with fertilization and hatching rates using a linear regression (P>0.05). We observed a weak correlation between the results of the staining tests and the fertilization and hatching rates in both species. TB integrity tests were not effective in predicting spawning viability in C. macropomum and B. amazonicus.(AU)

Atualmente não existem técnicas efetivas para avaliar a qualidade de oócitos na piscicultura deforma prática e acessível. O teste de integridade da membrana celular com corante vital azul detripan (AT) surge como uma alternativa. Nesse estudo, oócitos de Colossoma macropomum e Bryconamazonicus foram expostos a diferentes concentrações de AT, buscando verificar uma possível relação entre os resultados dos testes de coloração e as taxas reprodutivas. Oócitos foram expostos a concentrações de 0,05; 0,04; 0,03; 0,02 e 0,01% de AT durante 1 minuto e, posteriormente avaliados em estereomicroscópio. A porcentagem de oócitos não corados (intactos) de cada amostra foicorrelacionada com as taxas de fertilização e eclosão utilizando análise de regressão linear (P>0,05). Fraca correlação entre resultados dos tratamentos e as taxas de fertilização e eclosão nas duas espécies foi observada. Os testes de integridade com AT foram ineficazes em predizer o sucesso da desova em C. macropomum e B. amazonicus(AU)

Trypan blue staining is not efficient in determining oocyte viability in Colossoma macropomum and Brycon amazonicus / Coloração com azul de tripan não é eficiente na determinação da viabilidade de oócitos em Colossoma macropomum e Brycon amazonicus

Currently, there is no effective technique to evaluate the quality of oocytes in fish farming in apractical and affordable way. The cell membrane integrity test with the vital dye trypan blue (TB)could be an option. In this study, Colossoma macropomum and Brycon amazonicus oocytes were exposed to different TB concentrations seeking to verify a possible relationship between the results of staining tests and reproductive rates. Oocytes were exposed to concentrations of 0.05, 0.04, 0.03, 0.02 and 0.01% TB for 1 minute and subsequently were evaluated under a stereomicroscope. The percentage of unstained (viable) oocytes from each sample was correlated with fertilization and hatching rates using a linear regression (P>0.05). We observed a weak correlation between the results of the staining tests and the fertilization and hatching rates in both species. TB integrity tests were not effective in predicting spawning viability in C. macropomum and B. amazonicus.

Atualmente não existem técnicas efetivas para avaliar a qualidade de oócitos na piscicultura deforma prática e acessível. O teste de integridade da membrana celular com corante vital azul detripan (AT) surge como uma alternativa. Nesse estudo, oócitos de Colossoma macropomum e Bryconamazonicus foram expostos a diferentes concentrações de AT, buscando verificar uma possível relação entre os resultados dos testes de coloração e as taxas reprodutivas. Oócitos foram expostos a concentrações de 0,05; 0,04; 0,03; 0,02 e 0,01% de AT durante 1 minuto e, posteriormente avaliados em estereomicroscópio. A porcentagem de oócitos não corados (intactos) de cada amostra foicorrelacionada com as taxas de fertilização e eclosão utilizando análise de regressão linear (P>0,05). Fraca correlação entre resultados dos tratamentos e as taxas de fertilização e eclosão nas duas espécies foi observada. Os testes de integridade com AT foram ineficazes em predizer o sucesso da desova em C. macropomum e B. amazonicus

Evolutionary Relationships among Boulengerella Species (Ctenoluciidae, Characiformes): Genomic Organization of Repetitive DNAs and Highly Conserved Karyotypes.

Ctenoluciidae is a Neotropical freshwater fish family whose representatives are known as bicudas. The genus Boulengerella contains 5 species, and 4 of them (B. cuvieri, B. lateristriga, B. lucius, and B. maculata) were cytogenetically analyzed in the present study by conventional and molecular procedures. All 4 species have a very similar karyotype, with 2n = 36 chromosomes (14 metacentrics + 16 submetacentrics + 6 subtelocentrics; FN = 72). However, the heterochromatin distribution pattern is species-specific. In all 4 species, the nucleolus organizer region is located in pair 18, as also confirmed by cytogenetic mapping of 18S rDNA. In turn, 5S rRNA genes are present in 2 chromosome pairs: in pair 1 of all 4 species, and in pair 10 of B. lateristriga, B. maculata, and B. cuvieri, but in pair 4 of B. lucius. The telomeric probe highlighted terminal regions in all chromosomes, as well as an interstitial centromeric sequence in pair 3 of the 3 first-mentioned species. Notably, a conspicuous heteromorphic secondary constriction in chromosomes 18 was found only in the males of the 3 species, rendering one of the homologs much larger than the other one. This feature, associated with a large 18S rDNA block and accumulation of telomeric sequences, suggests the presence of an XX/XY sex chromosome system in the analyzed Boulengerella species.

Description of the reproductive behavior of Symphysodon aequifasciatus (Cichlidae) in captivity / Descrição do comportamento reprodutivo de Symphysodon equifasciatus (Cichlidae) em cativeiro

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.(AU)

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.(AU)

Description of the reproductive behavior of Symphysodon aequifasciatus (Cichlidae) in captivity / Descrição do comportamento reprodutivo de Symphysodon equifasciatus (Cichlidae) em cativeiro

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.

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.

Caracterização físico-química e rendimento do filé e resíduos de diferentes espécies de jaraqui (Semaprochilodus spp. ) / Physicochemical characterization and fillet and waste yield of different species of jaraqui (Semaprochilodus spp. )

Jaraqui is a fish found in the Amazon basin. The species has low commercial value when compared to noble fish of the region, such as tambaqui, arapaima and matrinxã, being consumed mostly by the low-income population. To better use of this fish and to aggregate value, we analyzed two filleting procedures, chemical composition and fillet yield of two jaraqui species, as well as the performance of their waste. The work was developed in two stages; the first, two filleting methods were analyzed, and biometrics taken; in the second stage we used the methodology filleting presented the best performance, biometrics were taken and analyzed the chemical composition of the fillets. The results showed that the method of filleting and subsequent removal of the skin was that provided greater fillet yield. In the second stage, the skinless fillet yield ranged between 30.96 and 32.29% and the fillet with skin between 40.29 and 41.20% for jaraqui of coarse scale and fine scale respectively. The residues showed yield from 67.62 to 69.15% of body weight for jaraquis of coarse scale and fine scale, respectively. Regarding centesimal composition, only protein levels did not differ between species (p>0.05), and both showed high lipid content, which may be related to the period in which they were acquired, the migration to spawning. We conclude therefore that both species exhibited good fillet yield and residue, indicating that can be exploited by processingand handicrafts industries.(AU)

Jaraqui é um peixe encontrado na bacia Amazônica, que possui baixo valor comercial quando comparado a peixes nobres da região, como o tambaqui, pirarucu e matrinxã, sendo consumido pela maioria da população de baixa renda. Visando o melhor aproveitamento e agregação de valor a esse pescado, foram analisados dois procedimentos de filetagem, composição centesimal e rendimento do filé de duas espécies de jaraqui, assim como o rendimento de seus resíduos. O trabalho foi desenvolvido em duas etapas; na primeira foram analisadas duas metodologias de filetagem e tomados dados biométricos; na segunda etapa foi utilizada a metodologia de filetagem que apresentou melhor rendimento, foram tomados dados biométricos e analisada a composição centesimal dos filés. Os resultados apontaram que a metodologia de filetagem e posterior retirada da pele foi a que proporcionou um maior rendimento de filé. Na segunda etapa, o rendimento de filé sem pele variou entre 30,96 e 32,29%, e de filé com pele, entre 40,29 e 41,20% para jaraqui de escama grossa e escama fina, respectivamente. Os resíduos apresentaram rendimento de 67,62% a 69,15% do peso corporal de jaraquis de escama fina e escama grossa, respectivamente. Com relaçãoà composição centesimal, apenas teores de proteína não diferiram entre as espécies (p>0,05), e ambas apresentaram altos teores de lipídios, fato que pode estar relacionado ao período em que foram adquiridos, na migração para desova. Ambas as espécies apresentam bom rendimento de filé e de resíduos, indicando que podem ser aproveitadas pelas indústrias processadoras e de artesanato.(AU)

Caracterização físico-química e rendimento do filé e resíduos de diferentes espécies de jaraqui (Semaprochilodus spp. ) / Physicochemical characterization and fillet and waste yield of different species of jaraqui (Semaprochilodus spp. )

Jaraqui is a fish found in the Amazon basin. The species has low commercial value when compared to noble fish of the region, such as tambaqui, arapaima and matrinxã, being consumed mostly by the low-income population. To better use of this fish and to aggregate value, we analyzed two filleting procedures, chemical composition and fillet yield of two jaraqui species, as well as the performance of their waste. The work was developed in two stages; the first, two filleting methods were analyzed, and biometrics taken; in the second stage we used the methodology filleting presented the best performance, biometrics were taken and analyzed the chemical composition of the fillets. The results showed that the method of filleting and subsequent removal of the skin was that provided greater fillet yield. In the second stage, the skinless fillet yield ranged between 30.96 and 32.29% and the fillet with skin between 40.29 and 41.20% for jaraqui of coarse scale and fine scale respectively. The residues showed yield from 67.62 to 69.15% of body weight for jaraquis of coarse scale and fine scale, respectively. Regarding centesimal composition, only protein levels did not differ between species (p>0.05), and both showed high lipid content, which may be related to the period in which they were acquired, the migration to spawning. We conclude therefore that both species exhibited good fillet yield and residue, indicating that can be exploited by processingand handicrafts industries.

Jaraqui é um peixe encontrado na bacia Amazônica, que possui baixo valor comercial quando comparado a peixes nobres da região, como o tambaqui, pirarucu e matrinxã, sendo consumido pela maioria da população de baixa renda. Visando o melhor aproveitamento e agregação de valor a esse pescado, foram analisados dois procedimentos de filetagem, composição centesimal e rendimento do filé de duas espécies de jaraqui, assim como o rendimento de seus resíduos. O trabalho foi desenvolvido em duas etapas; na primeira foram analisadas duas metodologias de filetagem e tomados dados biométricos; na segunda etapa foi utilizada a metodologia de filetagem que apresentou melhor rendimento, foram tomados dados biométricos e analisada a composição centesimal dos filés. Os resultados apontaram que a metodologia de filetagem e posterior retirada da pele foi a que proporcionou um maior rendimento de filé. Na segunda etapa, o rendimento de filé sem pele variou entre 30,96 e 32,29%, e de filé com pele, entre 40,29 e 41,20% para jaraqui de escama grossa e escama fina, respectivamente. Os resíduos apresentaram rendimento de 67,62% a 69,15% do peso corporal de jaraquis de escama fina e escama grossa, respectivamente. Com relaçãoà composição centesimal, apenas teores de proteína não diferiram entre as espécies (p>0,05), e ambas apresentaram altos teores de lipídios, fato que pode estar relacionado ao período em que foram adquiridos, na migração para desova. Ambas as espécies apresentam bom rendimento de filé e de resíduos, indicando que podem ser aproveitadas pelas indústrias processadoras e de artesanato.

Ovarian development in the Amazonian red discus, Symphysodon discus Heckel (Osteichthyes: Cichlidae)

The Neotropical red discus fish, Symphysodon discus, originates from the Amazonian basin and has a discoid body. Although this species is popularly used in aquaria and is exported as an ornamental fish, it has not been intensively studied. The purpose of this work was to study the morphological and histological aspects of the ovarian development in the red discus. Forty females of S. discus of varying body sizes and different stages of gonadal development were used in this study. The ovaries were weighed and examined macroscopically in order to observe the maturation stages. Histological staining of hematoxilin-eosin was used for microscopic observations of the ovaries. Macroscopic observations showed immature, maturing, mature and partially spent stages of ovarian development. Microscopic examination of the ovaries revealed five stages and five phases of ovarian development. The ovaries of the mature females showed all the different phases of oocyte development, indicating the multiple spawning habit of this species.

O acará disco, Symphysodon discus, é um ciclídeo neotropical originário da bacia Amazônica e seu corpo apresenta formato discoidal. Embora esta espécie seja popularmente utilizada em aquariofilia e exportada como peixe ornamental, ainda é pouco estudada. Este trabalho teve como objetivo estudar os aspectos morfológicos e histológicos do desenvolvimento ovariano do acará disco. Para este estudo foram utilizadas 40 fêmeas de S. discus, de tamanhos diferentes, em várias fases de desenvolvimento gonadal. Os ovários foram pesados e examinados macroscopicamente para observar os estádios de maturação. Para as observações microscópicas dos ovários foi utilizada coloração de hematoxilina-eosina. Os resultados da análise macroscópica apresentaram os estádios de desenvolvimento ovariano imaturo, em maturação, maduro e parcialmente esvaziado. A análise microscópica dos ovários revelou cinco estádios e cinco fases de desenvolvimento ovariano. Os ovários das fêmeas maduras apresentaram todas as diferentes fases de desenvolvimento ovocitário, indicando a desova múltipla para a espécie estudada.

Aspectos morfológicos e ultraestruturais do Espermatozóide de Curimata Inornata Vari, 1989 (Pisces, Teleostei) do Rio Amazonas

Morphological and ultrastructural aspects of the spermatozoon of Curimata inornata Vari, 1989 (Pisces, Teleostei) is described by light and transmission electron microscopy, the spermatozoon head contains a nucleus ovoid-shaped, with granular chomatin electron dense, a short middle piece and a tail, with the classic 9+2 axoneme.

Estão descritos aspectos morfológicos e ultraestruturais do espermatozóide de Curimata inornata Vavi, 1989 (Pisces,Teleostei) observados com microsopia óptica e microscopia eletrônica de transmissão. O espermatozóide é constituído de cabeça, contendo um núcleo ovoide com cromatina granular densa, uma peça intermediária curta e uma cauda com a constituição axonêmica clássica de microtúbulos de 9p+2.