The effect of feeding frequency on the performance of juvenile cobia (Rachycentron canadum) / Efeito da frequência alimentar no desempenho de juvenis do cobia (Rachycentron canadum)

Para ajustar a frequência alimentar de juvenis de cobia ou beijupirá (Rachycentron canadum), 540 juvenis, com peso médio de 2,0 g (± 0,4) e comprimento médio de 8,7cm (± 0,5), foram distribuídos em quatro tratamentos: T2, T4, T6 e T8 (alimentação realizada duas, quatro, seis e oito vezes ao dia, respectivamente). Cada tratamento teve três repetições. Os juvenis de beijupirá foram alimentados em regime ad libitum. Observou-se diferença significativa no peso final (P<0,05), tendo os peixes do tratamento que receberam ração duas vezes ao dia (T2) apresentado peso significativamente menor do que os peixes que receberam oito refeições ao dia (T8). Não houve diferença nas variáveis conversão alimentar, ganho de peso, comprimento e sobrevivência (P>0,05) entre os tratamentos. Assim, para juvenis de beijupirá, observou-se que a frequência de alimentação de oito refeições por dia, juntamente com um regime de alimentação ad libitum, é a mais adequada durante essa fase. Os dados obtidos no presente experimento permitem otimizar uma etapa da cadeia produtiva do beijupirá.

Zootechnical indices and digestibility in juveniles of tambaqui Colossoma macropomum fed a diet containing particulate maize / Índices zootécnicos e digestibilidade em juvenis de tambaqui Colossoma macropomum alimentados com dieta contendo milho particulado

Three experiments were done with different particle sizes of corn feed on its zootechnical performance, passing rate and apparent digestibility of juvenile tambaqui (Colossoma macropomum). In the first, 200 juveniles were used and distributed in 20 tanks (220 L), 10 fish per unit (four replicates). The experimental system used to record passage time was composed of five incubators with 200 L. In the second, 75 juveniles were used per 55 days (three replications). In the third, 75 juveniles were used and distributed in five incubators of 200 L. All experiments were performed randomly. Different linear behavior treatments were observed for apparent digestibility of crude protein; and the smaller particle size (150 μm) had better results digestibility. Smaller particle size of the corn had better results, affected the growth performance of tambaqui and the apparent digestibility of crude protein and ether extract. Thus, is recommended that a particle size of 150 μm of corn be used for tambaqui.(AU)

Três experimentos foram realizados com diferentes tamanhos de partícula de ração para o desempenho zootécnico, taxa de aprovação e digestibilidade aparente de tambaqui juvenil (Colossoma macropomum). No primeiro, foram utilizados 200 juvenis e distribuídos em 20 tanques (220 L), 10 peixes por unidade (quatro repetições). O sistema experimental utilizado para registrar o tempo de passagem foi composto por cinco incubadoras com 200 L. No segundo, 75 juvenis foram utilizados por 55 dias (três repetições). No terceiro, 75 juvenis foram utilizados e distribuídos em cinco incubadoras de 200 L. Todos os experimentos foram realizados aleatoriamente. Diferentes tratamentos de comportamento linear foram observados para digestibilidade aparente da proteína bruta; e o menor tamanho de partícula (150 μm) apresentou melhor digestibilidade dos resultados. menor tamanho de partícula do milho apresentou melhores resultados, afetou o desempenho de crescimento de tambaquis e a digestibilidade aparente da proteína bruta e extrato etéreo. Portanto, recomenda-se o uso de um tamanho de partícula de 150 μm de milho para o tambaqui.(AU)

Zootechnical indices and digestibility in juveniles of tambaqui Colossoma macropomum fed a diet containing particulate maize / Índices zootécnicos e digestibilidade em juvenis de tambaqui Colossoma macropomum alimentados com dieta contendo milho particulado

Three experiments were done with different particle sizes of corn feed on its zootechnical performance, passing rate and apparent digestibility of juvenile tambaqui (Colossoma macropomum). In the first, 200 juveniles were used and distributed in 20 tanks (220 L), 10 fish per unit (four replicates). The experimental system used to record passage time was composed of five incubators with 200 L. In the second, 75 juveniles were used per 55 days (three replications). In the third, 75 juveniles were used and distributed in five incubators of 200 L. All experiments were performed randomly. Different linear behavior treatments were observed for apparent digestibility of crude protein; and the smaller particle size (150 μm) had better results digestibility. Smaller particle size of the corn had better results, affected the growth performance of tambaqui and the apparent digestibility of crude protein and ether extract. Thus, is recommended that a particle size of 150 μm of corn be used for tambaqui.

Três experimentos foram realizados com diferentes tamanhos de partícula de ração para o desempenho zootécnico, taxa de aprovação e digestibilidade aparente de tambaqui juvenil (Colossoma macropomum). No primeiro, foram utilizados 200 juvenis e distribuídos em 20 tanques (220 L), 10 peixes por unidade (quatro repetições). O sistema experimental utilizado para registrar o tempo de passagem foi composto por cinco incubadoras com 200 L. No segundo, 75 juvenis foram utilizados por 55 dias (três repetições). No terceiro, 75 juvenis foram utilizados e distribuídos em cinco incubadoras de 200 L. Todos os experimentos foram realizados aleatoriamente. Diferentes tratamentos de comportamento linear foram observados para digestibilidade aparente da proteína bruta; e o menor tamanho de partícula (150 μm) apresentou melhor digestibilidade dos resultados. menor tamanho de partícula do milho apresentou melhores resultados, afetou o desempenho de crescimento de tambaquis e a digestibilidade aparente da proteína bruta e extrato etéreo. Portanto, recomenda-se o uso de um tamanho de partícula de 150 μm de milho para o tambaqui.

Zootechnical indices and digestibility in juveniles of tambaqui Colossoma macropomum fed a diet containing particulate maize

Abstract Three experiments were done with different particle sizes of corn feed on its zootechnical performance, passing rate and apparent digestibility of juvenile tambaqui (Colossoma macropomum). In the first, 200 juveniles were used and distributed in 20 tanks (220 L), 10 fish per unit (four replicates). The experimental system used to record passage time was composed of five incubators with 200 L. In the second, 75 juveniles were used per 55 days (three replications). In the third, 75 juveniles were used and distributed in five incubators of 200 L. All experiments were performed randomly. Different linear behavior treatments were observed for apparent digestibility of crude protein; and the smaller particle size (150 m) had better results digestibility. smaller particle size of the corn had better results, affected the growth performance of tambaqui and the apparent digestibility of crude protein and ether extract. Thus, is recommended that a particle size of 150 m of corn be used for tambaqui.

Resumo Três experimentos foram realizados com diferentes tamanhos de partícula de ração para o desempenho zootécnico, taxa de aprovação e digestibilidade aparente de tambaqui juvenil (Colossoma macropomum). No primeiro, foram utilizados 200 juvenis e distribuídos em 20 tanques (220 L), 10 peixes por unidade (quatro repetições). O sistema experimental utilizado para registrar o tempo de passagem foi composto por cinco incubadoras com 200 L. No segundo, 75 juvenis foram utilizados por 55 dias (três repetições). No terceiro, 75 juvenis foram utilizados e distribuídos em cinco incubadoras de 200 L. Todos os experimentos foram realizados aleatoriamente. Diferentes tratamentos de comportamento linear foram observados para digestibilidade aparente da proteína bruta; e o menor tamanho de partícula (150 m) apresentou melhor digestibilidade dos resultados. menor tamanho de partícula do milho apresentou melhores resultados, afetou o desempenho de crescimento de tambaquis e a digestibilidade aparente da proteína bruta e extrato etéreo. Portanto, recomenda-se o uso de um tamanho de partícula de 150 m de milho para o tambaqui.

Zootechnical indices and digestibility in juveniles of tambaqui Colossoma macropomum fed a diet containing particulate maize / Índices zootécnicos e digestibilidade em juvenis de tambaqui Colossoma macropomum alimentados com dieta contendo milho particulado

Three experiments were done with different particle sizes of corn feed on its zootechnical performance, passing rate and apparent digestibility of juvenile tambaqui (Colossoma macropomum). In the first, 200 juveniles were used and distributed in 20 tanks (220 L), 10 fish per unit (four replicates). The experimental system used to record passage time was composed of five incubators with 200 L. In the second, 75 juveniles were used per 55 days (three replications). In the third, 75 juveniles were used and distributed in five incubators of 200 L. All experiments were performed randomly. Different linear behavior treatments were observed for apparent digestibility of crude protein; and the smaller particle size (150 µm) had better results digestibility. smaller particle size of the corn had better results, affected the growth performance of tambaqui and the apparent digestibility of crude protein and ether extract. Thus, is recommended that a particle size of 150 µm of corn be used for tambaqui.

Três experimentos foram realizados com diferentes tamanhos de partícula de ração para o desempenho zootécnico, taxa de aprovação e digestibilidade aparente de tambaqui juvenil (Colossoma macropomum). No primeiro, foram utilizados 200 juvenis e distribuídos em 20 tanques (220 L), 10 peixes por unidade (quatro repetições). O sistema experimental utilizado para registrar o tempo de passagem foi composto por cinco incubadoras com 200 L. No segundo, 75 juvenis foram utilizados por 55 dias (três repetições). No terceiro, 75 juvenis foram utilizados e distribuídos em cinco incubadoras de 200 L. Todos os experimentos foram realizados aleatoriamente. Diferentes tratamentos de comportamento linear foram observados para digestibilidade aparente da proteína bruta; e o menor tamanho de partícula (150 µm) apresentou melhor digestibilidade dos resultados. menor tamanho de partícula do milho apresentou melhores resultados, afetou o desempenho de crescimento de tambaquis e a digestibilidade aparente da proteína bruta e extrato etéreo. Portanto, recomenda-se o uso de um tamanho de partícula de 150 µm de milho para o tambaqui.

Zootechnical indices and digestibility in juveniles of tambaqui Colossoma macropomum fed a diet containing particulate maize.

Three experiments were done with different particle sizes of corn feed on its zootechnical performance, passing rate and apparent digestibility of juvenile tambaqui (Colossoma macropomum). In the first, 200 juveniles were used and distributed in 20 tanks (220 L), 10 fish per unit (four replicates). The experimental system used to record passage time was composed of five incubators with 200 L. In the second, 75 juveniles were used per 55 days (three replications). In the third, 75 juveniles were used and distributed in five incubators of 200 L. All experiments were performed randomly. Different linear behavior treatments were observed for apparent digestibility of crude protein; and the smaller particle size (150 µm) had better results digestibility. smaller particle size of the corn had better results, affected the growth performance of tambaqui and the apparent digestibility of crude protein and ether extract. Thus, is recommended that a particle size of 150 µm of corn be used for tambaqui.

Antibacterial activity of Barbatimão (Stryphnodendron adstringens) against Staphylococcus aureus: in vitro and in silico studies.

We evaluated the activity of the aqueous fraction and the ethyl acetate fraction of Stryphnodendron adstringens against Staphylococcus aureus and proposed their mechanism of action. The antibacterial activity of S. adstringens fractions was evaluated against S. aureus and the cell targets were rated by docking. The fractions showed moderate antibacterial activity against S. aureus without toxicity on two mammalian cell lines. They also showed synergistic antibacterial activity with tannic acid (TA). In silico assays indicated FabG, FabZ and FabI as probable targets. The metabolic pathway for fatty acid biosynthesis in S. aureus was affected by components of S. adstringens. The synergistic effect when combining TA with S. adstringens fractions suggests a natural alternative to S. aureus control. SIGNIFICANCE AND IMPACT OF THE STUDY: This is the first study describing the possible targets of action of Stryphnodendron adstringens on Staphylococcus aureus. Molecular dynamics simulations showed that the components of S. adstringens affected the metabolic pathway for fatty acid biosynthesis (FAS II) in S. aureus, inhibiting the FabI, FabG and FabZ enzymes. As tannic acid (TA) is a known inhibitor of some targets identified, we showed synergistic antibacterial activity of S. adstringens in combination with TA. This combination did not show toxicity against HaCaT and Vero cells and based on all these results we suggest that S. adstringens can be a natural and sustainable alternative to S. aureus control.

FATAL cryptococcal meningitis in a child with hyper-immunoglobulin M syndrome, with an emphasis on the agent.

Following a fatal case of Cryptococcus neoformans meningitis in a child with X-linked hyper-immunoglobulin M syndrome (XHIGM), we evaluated the fungal isolate in an experimental infection in a mouse model with respect to microbiology, epidemiology, virulence and response to therapy. The minimum inhibitory concentrations for antifungals in the susceptibility test were 0.5mg/L for amphotericin B, 4.0mg/L for fluconazole and 0.12mg/L for voriconazole. Evaluation of pathogenicity by means of an experimental infection in BALB/c mice showed that fungus isolated from the blood and cerebrospinal fluid of the child was able to disseminate, reaching the spleen, lungs and brain, where it caused significant macroscopic alterations in the size and texture of each organ. Treatment of infected mice with amphotericin B reduced the fungal load in the spleen and lungs, but not in the brain.

A new small-molecule KRE2 inhibitor against invasive Candida parapsilosis infection.

AIM: To investigate the antifungal activity of MOL3, a small molecule that was selected by virtual screening, against Candida spp. MATERIALS & METHODS: The antifungal activity of MOL3 was evaluated using standard strains and clinical isolates. Activity was evaluated in both in vitro tests and animal models. RESULTS: The minimum fungicidal concentration of MOL3 against Candida spp. ranged from 16 to 128 mg/l. MOL3 at the sub-minimum fungicidal concentration inhibited hyphal elongation. The remaining yeast cells presented morphological changes and were metabolically inactive. MOL3 was toxicologically inert both in vitro and in the animal model. MOL3 also reduced experimental systemic infection by C. parapsilosis in mice. CONCLUSION: The selection of MOL3 by virtual screening was successful, revealing a promising antifungal candidate.

Metionina+cistina digestível para juvenis de tambaqui / Digestible methionine+cystine for tambaqui juveniles

Avaliou-se o efeito dos níveis de metionina+cistina digestível para juvenis de tambaqui na fase inicial de desenvolvimento (3,03±0,06g) durante 45 dias. Foram utilizados 160 juvenis de tambaqui distribuídos em DIC, com cinco tratamentos (níveis de metionina+cistina digestível = 0,66; 0,73; 0,80; 0,87; 0,94%), quatro repetições e oito animais por unidade experimental. As dietas utilizadas foram isoproteicas (25%) e isoenergéticas (3200kcal.kg-1). Os resultados obtidos foram submetidos aos testes de homogeneidade, normalidade, à análise de variância e à análise de regressão. Os parâmetros físicos e químicos da água do sistema de recirculação ficaram dentro da faixa de tolerância para a espécie. Os níveis de metionina+cistina digestíveis avaliados não influenciaram (P>0,05) a sobrevivência, o índice hepatossomático, o índice de gordura visceral e o consumo de ração. Entretanto, ganho de peso e taxa de eficiência proteica apresentaram aumento linear (P<0,05) com aumento da metionina + cistina na ração. Verificou-se que os níveis de metionina + cistina para o tambaqui não foram completamente atendidos, sendo recomendada a realização de novos estudos.(AU)

This study aimed to determine digestible methionine+cystine requirement of tambaqui juveniles in the early stage of development (3.03 ± 0.06 g) lasting 45 days. 160 tambaqui juveniles were distributed into DIC, with five treatments (methionine + cystine = 0.66; 0.73; 0.80; 0.87; 0.94%), four replications and eight animals per experimental unit. The basal diets were isonitrogenous (25% crude protein) and isocaloric (3200kcal.kg-1). The results were submitted to the homogeneity test, normality test, analysis of variance, and regression analysis. The physical and chemical parameters of water from the water recirculation system were within those recommended for the species. Digestible methionine+cystine levels did not influence (P>0.05) the survival, hepatosomatic index, visceral fat index and feed intake. However, weight gain and protein efficiency ratio exhibit a linear increase (P<0.05) with increase in methionine and cystine in the feed. Our results showed that the methionine + cystine levels for tambaqui were not fully met, and new studies are recommended.(AU)

Metionina+cistina digestível para juvenis de tambaqui / Digestible methionine+cystine for tambaqui juveniles

Avaliou-se o efeito dos níveis de metionina+cistina digestível para juvenis de tambaqui na fase inicial de desenvolvimento (3,03±0,06g) durante 45 dias. Foram utilizados 160 juvenis de tambaqui distribuídos em DIC, com cinco tratamentos (níveis de metionina+cistina digestível = 0,66; 0,73; 0,80; 0,87; 0,94%), quatro repetições e oito animais por unidade experimental. As dietas utilizadas foram isoproteicas (25%) e isoenergéticas (3200kcal.kg-1). Os resultados obtidos foram submetidos aos testes de homogeneidade, normalidade, à análise de variância e à análise de regressão. Os parâmetros físicos e químicos da água do sistema de recirculação ficaram dentro da faixa de tolerância para a espécie. Os níveis de metionina+cistina digestíveis avaliados não influenciaram (P>0,05) a sobrevivência, o índice hepatossomático, o índice de gordura visceral e o consumo de ração. Entretanto, ganho de peso e taxa de eficiência proteica apresentaram aumento linear (P<0,05) com aumento da metionina + cistina na ração. Verificou-se que os níveis de metionina + cistina para o tambaqui não foram completamente atendidos, sendo recomendada a realização de novos estudos.(AU)

This study aimed to determine digestible methionine+cystine requirement of tambaqui juveniles in the early stage of development (3.03 ± 0.06 g) lasting 45 days. 160 tambaqui juveniles were distributed into DIC, with five treatments (methionine + cystine = 0.66; 0.73; 0.80; 0.87; 0.94%), four replications and eight animals per experimental unit. The basal diets were isonitrogenous (25% crude protein) and isocaloric (3200kcal.kg-1). The results were submitted to the homogeneity test, normality test, analysis of variance, and regression analysis. The physical and chemical parameters of water from the water recirculation system were within those recommended for the species. Digestible methionine+cystine levels did not influence (P>0.05) the survival, hepatosomatic index, visceral fat index and feed intake. However, weight gain and protein efficiency ratio exhibit a linear increase (P<0.05) with increase in methionine and cystine in the feed. Our results showed that the methionine + cystine levels for tambaqui were not fully met, and new studies are recommended.(AU)

Tongue coating frequency and its colonization by yeasts in chronic kidney disease patients.

The objective of this study was to investigate tongue coating (TC) frequency and its colonization by yeasts in a group of chronic kidney disease (CKD) patients. Clinical examination of the oral mucosa of 33 CKD patients was performed to investigate oral and tongue lesions. TC was diagnosed according to its clinical characteristics. Stimulated saliva and TC samples were collected to verify the salivary flow, and determine yeast frequency, species and counts. TC was found in 18/33 of the patients (54.55 %) and was the most frequent oral lesion found. Of 18 patients with TC, 13 (72.22 %) presented positive cultures for yeasts on the tongue dorsum, and one (5.55 %) in the saliva only. Yeasts were significantly more frequent in the tongue dorsum when compared to the saliva (p = 0.0106). The most frequent yeast species found was C. albicans (55.55 %), while C. parapsilosis comprised 50 % of non-albicans Candida species. This study demonstrated high amounts of yeasts on the cultures from TC samples of CKD patients, strongly suggesting that TC is a clinical representation of a polymicrobial biofilm, which could serve as a gateway for disseminated infection in immunosuppressed patients undergoing frequent hospitalization.

Spermatogenesis and nucleolar behavior in Triatoma vandae and Triatoma williami (Hemiptera, Triatominae).

This study describes spermatogenesis in Triatoma vandae and the nucleolar behavior of T. vandae and Triatoma williami, with a cytotaxonomic focus. Analysis of mitotic and meiotic metaphases of T.vandae confirms the species karyotype. T. vandae presents some characteristics during meiosis that differentiate it from T. williami, including the presence of a chromocenter with two sex chromosomes individualized during early prophase, and the presence of a bi- or tripartite corpuscle inpolyploid nuclei. It was possible to observe the compaction of chromatin during prophase resulting in holocentric chromosomes. During metaphase,the autosomes presented a ring shape and the sex chromosomes were in the center of the ring. These chromosomes were separated in anaphase. Although it is common, we did not observe the phenomenon of late migration of the sex chromosomes. By means of silver ion impregnation it was possible to describe nucleologenesis in T. vandae and T. williami. In both species we observed persistence of the nucleolar material duringmeiosis. In addition to the cells in meiotic division, we also observed the presence of polyploid nuclei in the seminiferous tubule walls that nourish the cells during cell division. The nucleolar markings reflect their capacity for synthetic activity. T. vandae and T. williami presented only one nucleolar corpuscle, which reflects low synthetic activity. This study confirms the karyotype of T. vandae, describes characteristics that differentiate T. vandae and T. williami during meiosis, and describes the phenomenon of nucleolar persistence in both species.

Flow cytometry reliability analysis and variations in sugarcane DNA content.

The aim of this study was to evaluate the reliability of flow cytometry analysis and the use of this technique to differentiate species and varieties of sugarcane (Saccharum spp) according to their relative DNA content. We analyzed 16 varieties and three species belonging to this genus. To determine a reliable protocol, we evaluated three extraction buffers (LB01, Marie, and Tris·MgCl2), the presence and absence of RNase, six doses of propidium iodide (10, 15, 20, 25, and 30 µg), four periods of exposure to propidium iodide (0, 5, 10, and 20 min), and seven external reference standards (peas, beans, corn, radish, rye, soybean, and tomato) with reference to the coefficient of variation and the DNA content. For statistical analyses, we used the programs Sisvar(®) and Xlstat(®). We recommend using the Marie extraction buffer and at least 15 µg propidium iodide. The samples should not be analyzed immediately after the addition of propidium iodide. The use of RNase is optional, and tomato should be used as an external reference standard. The results show that sugarcane has a variable genome size (8.42 to 12.12 pg/2C) and the individuals analyzed could be separated into four groups according to their DNA content with relative equality in the genome sizes of the commercial varieties.

Optical spectrum of bottom-up graphene nanoribbons: towards efficient atom-thick excitonic solar cells.

Recently, atomically well-defined cove-shaped graphene nanoribbons have been obtained using bottom-up synthesis. These nanoribbons have an optical gap in the visible range of the spectrum which make them candidates for donor materials in photovoltaic devices. From the atomistic point of view, their electronic and optical properties are not clearly understood. Therefore, in this work we carry out ab-initio density functional theory calculations combine with many-body perturbation formalism to study their electronic and optical properties. Through the comparison with experimental measurements, we show that an accurate description of the nanoribbon's optical properties requires the inclusion of electron-hole correlation effects. The energy, binding energy and the corresponding excitonic transitions involved are analyzed. We found that in contrast to zigzag graphene nanoribbons, the excitonic peaks in the absorption spectrum are a consequence of a group of transitions involving the first and second conduction and valence bands. Finally, we estimate some relevant optical properties that strengthen the potential of these nanoribbons for acting as a donor materials in photovoltaic.

Spermatogenesis in Triatoma melanocephala (Hemiptera: Triatominae).

Triatoma melanocephala is a rare species of Hemiptera. It belonged to the Brasiliensis subcomplex and presents morphological characteristics very close to those of Triatoma vitticeps. We investigated spermatogenesis of T. melanocephala and compared it with that of T. vitticeps in order to determine whether these organisms have similar cytogenetic characteristics. Lacto-acetic orcein staining was used to observe all stages of meiosis. These two species were found to have the same karyotype (2n = 20A + X1X2X3Y), heteropycnotic corpuscles in the polyploid spermatogonial cells, interfasic and profasic nucleus, and chromocenter with four sex chromosomes during prophase. Thus, we conclude that besides the morphologic similarity of T. melanocephala with T. vitticeps, they also have similar spermatogenesis and cytogenetics.

Efeito da densidade de estocagem no desenvolvimento inicial do acará-bandeira (Pterophyllum scalare) / The effect of storage density in the early development of angelfish (Pterophyllum scalare)

Avaliou-se a influência da densidade de estocagem no desenvolvimento inicial do acará-bandeira (Pterophyllum scalare). O desempenho produtivo foi avaliado pelo ganho de peso (GP), ganho de comprimento total (GCT), ganho de comprimento padrão (GCP), ganho de altura (GA), taxa de crescimento específico (TCE), taxa de desenvolvimento específico (TDE) e sobrevivência (S). Para realização do experimento, foram utilizadas 300 pós-larvas de peso médio inicial de 0,0012g, comprimento total médio de 4,11±0,93mm, altura média inicial de 4,84±0,87mm e comprimento padrão médio de 1,54±0,25mm. Essas foram distribuídas em delineamento inteiramente ao acaso, em cinco tratamentos com quatro repetições. Os tratamentos (T) foram constituídos por cinco diferentes densidades de estocagem, em que T1: 5 pós-larvas L-1; T2: 10 pós-larvas L-1; T3: 15 pós-larvas L-1; T4: 20 pós-larvas L-1; T5: 25 pós-larvas L-1. A densidade de 5 pós-larvas L-1 foi a que proporcionou o maior valor para crescimento. Contudo, essa densidade subestimou a utilização do espaço se comparada com a produtividade final da densidade de 15 pós-larvas L-1.

The influence of stocking density in the initial development of angelfish (Pterophyllum scalare) was evaluated. The productive performance was evaluated by weight gain (WG) gain length (GCT), standard length gain (GCP), height gain (GH), specific growth rate (TCE), specific development rate (TDE) and survival (S). For the experiment we used a total of 300 post-larvae angelfish with initial body weight of 0.0012 g, total length of 4.11±0.93mm, initial height of 4.84±0.87mm, and average standard length of 1.54±0.25mm. These were distributed in a completely randomized design in five treatments with four replications. The treatments consisted of five different stocking densities where T1: 5 post-larvae L-1, T2: 10 post-larvae L-1, T3: 15 post-larvae L-1, T4: 20 post-larvae L-1, T5: 25 post-larvae L-1. The physical and chemical water parameters were monitored daily. The density of post-larvae 5 L-1 was the one that gave the highest growth values. However, despite the post-larvae 5 L-1 density having provided larger animals, the density underestimates the use of space compared to the final productivity of the 15 post-larvae L-1density.

Efeito da densidade de estocagem no desenvolvimento inicial do acará-bandeira (Pterophyllum scalare) / The effect of storage density in the early development of angelfish (Pterophyllum scalare)

Avaliou-se a influência da densidade de estocagem no desenvolvimento inicial do acará-bandeira (Pterophyllum scalare). O desempenho produtivo foi avaliado pelo ganho de peso (GP), ganho de comprimento total (GCT), ganho de comprimento padrão (GCP), ganho de altura (GA), taxa de crescimento específico (TCE), taxa de desenvolvimento específico (TDE) e sobrevivência (S). Para realização do experimento, foram utilizadas 300 pós-larvas de peso médio inicial de 0,0012g, comprimento total médio de 4,11±0,93mm, altura média inicial de 4,84±0,87mm e comprimento padrão médio de 1,54±0,25mm. Essas foram distribuídas em delineamento inteiramente ao acaso, em cinco tratamentos com quatro repetições. Os tratamentos (T) foram constituídos por cinco diferentes densidades de estocagem, em que T1: 5 pós-larvas L-1; T2: 10 pós-larvas L-1; T3: 15 pós-larvas L-1; T4: 20 pós-larvas L-1; T5: 25 pós-larvas L-1. A densidade de 5 pós-larvas L-1 foi a que proporcionou o maior valor para crescimento. Contudo, essa densidade subestimou a utilização do espaço se comparada com a produtividade final da densidade de 15 pós-larvas L-1.(AU)

The influence of stocking density in the initial development of angelfish (Pterophyllum scalare) was evaluated. The productive performance was evaluated by weight gain (WG) gain length (GCT), standard length gain (GCP), height gain (GH), specific growth rate (TCE), specific development rate (TDE) and survival (S). For the experiment we used a total of 300 post-larvae angelfish with initial body weight of 0.0012 g, total length of 4.11±0.93mm, initial height of 4.84±0.87mm, and average standard length of 1.54±0.25mm. These were distributed in a completely randomized design in five treatments with four replications. The treatments consisted of five different stocking densities where T1: 5 post-larvae L-1, T2: 10 post-larvae L-1, T3: 15 post-larvae L-1, T4: 20 post-larvae L-1, T5: 25 post-larvae L-1. The physical and chemical water parameters were monitored daily. The density of post-larvae 5 L-1 was the one that gave the highest growth values. However, despite the post-larvae 5 L-1 density having provided larger animals, the density underestimates the use of space compared to the final productivity of the 15 post-larvae L-1density.(AU)

Karyotype and spermatogenesis in Triatoma lenti (Hemiptera: Triatominae), a potential Chagas vector.

All species of Triatominae are susceptible to infection by Trypanosoma cruzi (Kinetoplastida: Trypanosomatidae) and consequently, potential insect vectors of Chagas disease. Currently, there are 140 known species of triatomine bugs, which can be grouped into specific species complexes. The species Triatoma lenti (Hemiptera: Triatominae) is found only in Brazil and is considered a potential vector of Chagas disease. We karyotyped male T. lenti and examined its spermatogenesis in detail. The karyotype was found to be 2n = 20A + XY, demonstrating that this organism has the modal chromosome set found in triatomines. This new information concerning males of this species contributed to biological data that will be useful for understanding this potentially important Chagas disease vector.