Localization of peroxidase activity in blood mononuclear phagocytes in pacu fish (Piaractus mesopotamicus)

The localization of peroxidase activity in different cell regions is used as a criterion for classifying the stage of maturity of mammalian mononuclear phagocytes, with a positive peroxidase reaction indicating the presence of monoblasts, promonocytes, monocytes, and macrophages. Peroxidase activity was observed ultrastructurally in the circulating blood of pacu fish (Piaractus mesopotamicus), identifying monoblasts, promonocytes, monocytes, and macrophages. These observations suggest that differentiation of mononuclear phagocytes occurs in the blood circulation of fish, whereas in mammals, monoblasts and promonocytes are detected in bone marrow, with only monocytes detected in circulating blood and differentiation into macrophages occurring in other body compartments

Morphometry and morphology of nucleus of the Sertoli and interstitial cells of the tambaqui Colossoma macropomum (Cuvier, 1881) (Pisces: Characidae) during the reproductive cycle

This study allowed the characterization of the tambaqui Colossoma macropomum testes structural organization, emphasizing Sertoli and interstitial cells and analyzing morphometrically the Sertoli cell nucleus diameter and the interstitial tissue area during the reproductive cycle. Fragments of tambaqui testes were collected in the following reproductive cycle stages: immature, resting, maturation I and II, mature, and regression, and were histologically processed. The Sertoli cells were found at the periphery of the cysts of germinative lineage cells and the nuclei were shown to be smaller as these cells developed. The interstitial cells were better observed between the seminiferous lobules next to vessels in the interstitial tissue of maturing testes

Morphological and morphometric aspects of early life stages of piabanha Brycon gouldingi (Characidae)

Adult specimens of piabanha Brycon gouldingi were collected from Rio das Mortes (Mato Grosso, Brazil), adapted to captivity and induced to spawn at Buriti Fisheries (Nova Mutum, MT, Brazil). The early developmental stages of B. gouldingi were then characterized. Samples were collected at pre-determined times from oocyte extrusion to total yolk absorption. Oocyte diameter, total larval length (L-T) and yolk-sac volume were measured. The mean +/- s.d. duration of embryo developmental of B. gouldingi was 1390 +/- 006 h at 2640 +/- 113 degrees C. The mean +/- s.d. oocyte diameter was 113 +/- 006 mm with 54% of oocytes ranging from 111 to 120 mm. Seven stages characterized the early developmental phase of this species: zygote, cleavage, morula, blastula, gastrula, histogenesis-organogenesis and hatching, with unique features related to each stage. At hatching, the larvae measured 340 +/- 007 mm, presented an elongated shape with yolk-sac volume of 046 +/- 008 mu l, non-pigmented eyes and exhibited swimming ability. When the yolk was completely absorbed at 55 h post-hatch, mean +/- larval L-T was 668 +/- 065 mm, the eyes were highly pigmented and the teeth were visible. These are the first reported findings on the initial developmental stages of B. gouldingi and could be used to improve captive breeding management and conservation practices.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq

Spatial and seasonal patterns in fish assemblage in Corrego Rico, upper Parana River basin

The upper Paraná River basin drains areas of intensive industry and agriculture, suffering negative impacts. The Córrego Rico flows through sugar cane fields and receives urban wastewater. The aim of this work is to describe and to compare the fish assemblage structure in Córrego Rico. Six standardized bimonthly samples were collected between August 2008 and June 2009 in seven different stretches of Córrego Rico. Fishes were collected with an experimental seine and sieves, euthanized, fixed in formalin and preserved in ethanol for counting and identification. Data were recorded for water parameters, instream habitat and riparian features within each stretch. Non-metric multidimensional scaling, species richness and diversity analysis were performed to examine spatial and seasonal variation in assemblage structure. Fish assemblage structure was correlated with instream habitat and water parameters. The fish assemblage was divided in three groups: upper, middle and lower reaches. High values of richness and diversity were observed in the upper and lower stretches due to connectivity with a small lake and Mogi Guaçu River, respectively. Middle stretches showed low values of richness and diversity suggesting that a small dam in the middle stretch negatively impacts the fish assemblage. Seasonal differences in fish assemblage structure were observed only in the lower stretches

Morfologia e histologia do oviduto de marrecas Ana boschas

Avaliaram-se o comprimento do infundíbulo, do magno, do istmo, do útero e da vagina e o número de pregas do magno e do istmo do oviduto de 20 marrecas Ana boschas na fase reprodutiva. O infundíbulo apresenta mucosa com pregas longitudinais e baixas, revestidas por epitélio pseudoestratificado cilíndrico ciliado, com células caliciformes. O magno, compartimento mais longo do oviduto, 25,38cm±3,20, encontra-se constituído por uma camada mucosa com pregas altas e espessas revestidas por células cilíndricas ciliadas e abundantes células caliciformes. O istmo é formado por uma mucosa com pregas estreitas e curtas e numerosas glândulas tubulares que se estendem para o interior da lâmina própria. O útero, região curta do oviduto, 5,25cm±1,26, apresenta parede com pregas e cristas baixas e numerosas glândulas tubulares enoveladas, dirigidas para o interior da lâmina própria. A vagina, um estreito tubo muscular, está constituído por oito anéis circulares, em média, e uma camada muscular altamente desenvolvida e espessa. A morfologia do oviduto da marreca apresenta características morfológicas e histológicas distintas dos galiniformes, observando-se que a vagina e a porção cranial do infundíbulo apresentam pregas e células caliciformes, respectivamente, sendo estas últimas estruturas ausentes nos galiniformes.The length of infundibulum, magnum, isthmus, uterus, vagina, and the number of oviduct, magnum, and isthmus folds were evaluated in 20 Ana boschas female ducks in the reproductive phase. The infundibulum presented mucous membrane with longitudinal and short folds, covered by ciliated columnar pseudostratified epithelium, with goblet cells. Magnum, the longest oviduct compartment, 25.38cm±3.20, is constituted by mucous membrane with high and thick folds that are covered by ciliated columnar cells and many goblet cells. Isthmus is formed by mucous membrane with narrow and short folds, and many tubular glands that extend inside lamina propria. Uterus, an oviduct short region, 5.25cm±1.26, presented surface with short folds and crests, and numerous reeled tubular glands, that are directed inside lamina propria. Vagina, a strait muscular tube, is constituted by, approximately, eight circular rings, and a very developed and thick muscular layer. The oviduct morphology of female ducks presented different morphological and histological characteristics from Galliformes, because vagina and infundibulum cranial portion present folds and goblet cells, respectively, and the last cited structures are absent in Galliformes.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP

Newcastle disease in white Pekin ducks: response to experimental vaccination and challenge

A total of 120 Pekin ducks were distributed at random into four experimental groups, vaccinated or not against Newcastle disease (ND): G1 (Ulster 2C strain), G2 (B1 strain), G3 (LaSota strain), and G4 (nonvaccinated group). At 60 days of age, all groups were challenged with a pathogenic ND virus (NDV) suspension, and a group of specific pathogen free (SPF) chicks (G5) was also inoculated. Cloacal and tracheal swabs from all birds were collected after six, 14, 20, and 30 days post-challenge for virus isolation. NDV was isolated in 100% of SPF chicks. Pekin ducks from all groups, vaccinated or not, did not show any ND clinical signs, demonstrating that these birds are not susceptible to ND clinical disease. In the control group (G4), the virus was isolated 20 to 30 days after challenge, suggesting their possible NDV carrier state. In the vaccinated groups, no virus was isolated. This demonstrates that vaccination of white Pekin ducks against NDV is important to reduce NDV shedding in the field

Spatial and seasonal patterns in fish assemblage in Córrego Rico, upper Paraná river Basin

The upper Paraná River basin drains areas of intensive industry and agriculture, suffering negative impacts. The Córrego Rico flows through sugar cane fields and receives urban wastewater. The aim of this work is to describe and to compare the fish assemblage structure in Córrego Rico. Six standardized bimonthly samples were collected between August 2008 and June 2009 in seven different stretches of Córrego Rico. Fishes were collected with an experimental seine and sieves, euthanized, fixed in formalin and preserved in ethanol for counting and identification. Data were recorded for water parameters, instream habitat and riparian features within each stretch. Non-metric multidimensional scaling, species richness and diversity analysis were performed to examine spatial and seasonal variation in assemblage structure. Fish assemblage structure was correlated with instream habitat and water parameters. The fish assemblage was divided in three groups: upper, middle and lower reaches. High values of richness and diversity were observed in the upper and lower stretches due to connectivity with a small lake and Mogi Guaçu River, respectively. Middle stretches showed low values of richness and diversity suggesting that a small dam in the middle stretch negatively impacts the fish assemblage. Seasonal differences in fish assemblage structure were observed only in the lower stretches. © 2013 Sociedade Brasileira de Ictiologia.Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq

Sexagem histológica e desempenho de Oreochromis niloticus testando diâmetros de ração de acordo com o aparato bucal

Estudou-se o tamanho da boca de larvas de tilápia-do-nilo e testou-se o efeito de diferentes granulometrias da ração sobre o ganho de peso, comprimento e sobrevivência das larvas aos 30 e 60 dias de arraçoamento. Avaliou-se também o método de sexagem por meio de microscopia de luz aos 35 dias de idade. A medida da boca das larvas apresentou valores médios de 918,2±152,9μm aos cinco dias de idade. de acordo com esse dado, testaram-se três granulometrias: 0,25, 0,35 e 0,50mm. Aos 30 e aos 60 dias de arraçoamento, 10% das larvas foram medidas, pesadas e contadas para cálculo da taxa de sobrevivência. O tamanho dos grânulos testados não afetou o desempenho das larvas de tilápia nilótica com alimentação iniciada aos cinco dias pós-eclosão. Quanto à sexagem histológica aos 35 dias de idade, as gônadas apresentaram-se, em sua maioria, indiferenciadas. Recomenda-se que essa análise deva ser realizada de acordo com o tamanho dos animais e não com a idade.The mouth size of Nile tilapia larvae and the effect of different diameters of crumble fish food over weight gain, total length, and survival of larvae after 30 and 60 days of feeding were studied. The method of gender diagnosis based on light microscopy at 35 days of age was also evaluated. The larval mouth measurement presented average values of 918.2±152.9μm at five days of age. Based on this information, three granule sizes were tested: 0.25, 0.35, and 0.50mm. At 30 and 60 days of feeding, 10% of larvae were measured, weighed, and counted to calculate the survival rate. It was verified that the crumble size did not affect the performance of Nile tilapia larvae when feeding was initiated five days after hatching. In relation to the histological gender diagnosis at 35 days of age, most of gonads were undifferentiated. Therefore, it is recommended that this analysis should be carried out according to the size of animals instead of their age