930 resultados para Tilapia (Peixe)


Relevância:

20.00% 20.00%

Publicador:

Resumo:

O rio do Peixe, um dos principais afluentes do rio Tietê (Reservatório de Barra Bonita/Hidrovia Tietê Paraná), juntamente com seus formadores (microrregião geográfica de Botucatu - SP) constituem os principais mananciais das cidades que se localizam em suas bacias. A maior parte da bacia hidrográfica do rio do Peixe desenvolve-se sob rochas sedimentares arenosas, favoráveis às atividades de extração de areia, fato que aliado ao manejo incorreto do solo favorece a ocorrência de processos erosivos. Foram realizadas amostragens de água durante dez dias consecutivos e de sedimento durante três dias alternados, em dois períodos hidrológicos (seca e chuva), para a determinação de variáveis físicas, químicas e biológicas,com o objetivo principal de caracterizar do ponto de vista limnológico esse rio e sua foz. As análises das diferentes variáveis seguiram os métodos que são utilizados rotineiramente no Laboratório de Limnologia do CRHEA/EESC/USP. As águas do rio do Peixe apresentaram, principalmente altas concentrações de sólidos em suspensão. Os maiores valores de turbidez, condutividade, alcalinidade, HCO3-, CO3-, nitrito, nitrogênio amoniacal, nitrogênio Kjedhal, fosfato inorgânico, carbono orgânico e sólidos em suspensão foram obtidos durante o período de chuvas, influenciados principalmente pelo escoamento superficial que promove o carreamento de materiais da bacia hidrográfica. Foi possível ainda através das características limnológicas, agrupar as estações de amostragem ao longo do contínuo do rio em três regiões (alto, médio e baixo curso), e diferenciar do ponto de vista trófico as estações da foz com o rio Tietê. Um aumento da biomassa fitoplanctônica, no período de seca, no baixo curso do rio do Peixe foi favorecido pela menor vazão na barragem de Barra Bonita.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Aquaculture growth has intensified the need for a diversification of nutritionally appropriate aquafeed ingredients. The purpose of this study was to evaluate Spirulina, a blue-green microalgae, and soybean meal as the sole protein sources in grow-out Tilapia diets. We constructed 3 experimental diets with soybean meal and 0,15, 30, and 45% Spirulina (SBM, SP15, SP30, and SP45 respectively) as their main protein sources. We compared these diets to a commercial Tilapia diet (CC). Additionally, to evaluate the benefit of fishmeal inclusion, fishmeal was added (2 and 10%) to the most successful Spirulina containing diet (FM2, FM10). We evaluated these experimental diets based on their physical properties, palatability, growth potential, waste production, and overall cost. No significant differences in growth performance were found between any of the diets. Total ammonia nitrogen (TAN) and total phosphorus (TP) levels in each tank were significantly affected by diet (p<0.05). CC had significantly higher TP than the experimental diets and SP15 had significantly higher TAN than the other diets. Only CC was found to be significantly more palatable than the experimental diets, and Spirulina inclusion was inversely correlated to pellet stability. Lastly, SP15 was the most profitable experimental diet. We recommend eliminating fishmeal from grow-out Tilapia diets in favour of soybean meal and Spirulina. Spirulina should, however, be limited to 15% to avoid the negative effects it has on stability and profitability, and its possible effect on feed intake.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The thymic anlagen appears in Tilapia mossambica at 2 days post hatching and becomes lymphoid at 5 days. Lymphoid cells were first seen in the pronephros at 14 days and in the spleen at approximately five weeks of age. Differentiation into red and white pulp regions was seen by 10 weeks of age. Light and electron microscopic studies of adult lymphoid organ revealed increases in size and lymphoid cell numbers. Adult thymus develops a clearer corticomedullary differentiation of thymic corpuscles in the medulla and in the splenic red and white pulp became more distinct. Melanomacrophage centres were seen in spleen and pronephros. Adult fish gave primary and secondary antibody responses following challenge with sheep red bloods cells (SRBC), Escherichia coli (E. coli) and human gamma globulin (HGG). Plaque forming cell and immunocytoadherence assays revealed that head kidney and spleen were major sites for antibody production and development of antigen reactive cells. Proliferative activity in these organs was revealed using autoradiography and scintillation counting. Increased levels of pyroninophilia were also seen following antigenic challenge. Pilot studies on adults revealed that they were capable of rejecting first and second set allografts and leucocytes from spleen and head kidney proliferated in mixed leucocyte cultures. Antibody responses to SRBC, E. coli and HGG develop at about 10-12 weeks of age. Fry given either a single injection of SRBC at 10 weeks or two injections of the same antigen at 10 weeks and 12 days later, failed to respond to a further challenge with SRBC 56 days after the first injection (A time when animals would normally respond positively to this antigen). Injection of E. coli at the same times resulted in a prolonged antibody response.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Somatic growth in fishes is regulated by a variety of hormones. A central step in this hormonal network is the growth hormone-insulin-like growth factor-I (IGF-I) axis. Studies conducted evaluated the relationship of hepatic IGF-I (hIGF-1) mRNA with growth as affected by feeding regimes (satiation or restricted level; daily or alternate-day feeding), temperatures (high, ambient, low) and by social stress. To develop a cellular means for the quantification of hIGF-I mRNA levels in O. niloticus, hIGF-I cDNA was isolated and cloned. The partial sequence of IGF-I cDNA encodes for signal peptide, mature protein and a portion of the E-domain. A sensitive TaqMan quantitative reverse transcription-polymerase chain reaction (qRT-PCR) assay was developed based on the mature IGF-I. Using the developed qRT-PCR assay a significant positive correlation was observed between hIGF-I mRNA levels and growth rate of fish reared under different feeding regimes (r = 0.64) and temperature conditions (r = 0.64). On the dynamics of hIGF-I gene expression in response to elevated temperature, hIGF-I mRNA levels were significantly elevated after at least 2 days of exposure to warm temperature. This validates the concept that hIGF-I gene expressions are sufficiently sensitive to be used as a rapid growth rate indicator for O. niloticus. The hIGF-I levels have a significant positive correlation with specific growth rate (length; r = 0.92), and with condition factor (r = 0.55). On the effect of social stress, differential alterations in growth rates between the dominant and subordinates were observed which was attributed more to behavioral changes as transduced by physiological regulators. The fish's relative position in the social hierarchy was consistently reflected in the levels of hIGF-I mRNA and the eye color pattern. Subordination depressed hIGF-I levels while dominance stimulated it. These findings have shown that hGF-I level remained positively correlated to growth rate as affected by feeding regime, temperature and social stress. This suggests that hIGF-I plays a key role in controlling growth in O. niloticus and indicates that IGF-I mRNA quantification could prove useful for the rapid assessment of growth rate in this species of fish.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

This material is based upon work supported by the National Science Foundation through the Florida Coastal Everglades Long-Term Ecological Research program under Cooperative Agreements #DBI-0620409 and #DEB-9910514. This image is made available for non-commercial or educational use only.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Chondroitin sulfate (CS) is a naturally glycosaminoglycan found in the extracellular matrix of connective tissues and it may be extracted and purified those tissues. CS is involved in various biological functions, which may be related to the having structural variability, despite the simplicity of the linear chain structure from this molecule. Researches in biotechnology and pharmaceutical field with wastes from aquaculture has been developed in Brazil. In recent decades, tilapia (Oreochromis niloticus), native fish from Africa, has been one of the most cultivated species in various regions of the world, including Brazil. The tilapia farming is a cost-effective activity, however, it generates large amount of wastes that are discarded by producers. It is understood that waste from tilapia can be used in research as a source of molecules with important biotechnological applications, which also helps in reducing environmental impacts and promote the development of an ecofriendly activity. Thus, nile tilapia viscera were subjected to proteolysis, then the glycosaminoglycans were complexed with ion exchange resin (Lewatit), it was fractionated with increasing volumes of acetone and purified by ion exchange chromatography DEAE-Sephacel. Further, the fraction was analyzed by agarose gel electrophoresis and nuclear magnetic resonance (NMR). The electrophoretic profile of the compound together the analysis of 1H NMR spectra and the HSQC correlation allow to affirm that the compound corresponds to a molecule like chondroitin sulfate. MTT assay was used to assess cell viability in the presence of CS tilapia isolated and showed that the compound is not cytotoxic to normal cells such as cells from the mouse embryo fibroblast (3T3). Then, this compound was tested for the ability to reduce the influx of leukocytes in model of acute peritonitis (in vivo) induced by sodium thioglycolate. In this context, it was done total and differential leukocytes counting in the blood and peritoneal fluid collected respectively from vena cava and the peritoneal cavity of the animals subjected to the experiment. The chondroitin sulfate for the first time isolated from tilapia (CST ) was able to reduce the migration of leukocytes to the peritoneal cavity of inflamed mice until 80.4 per cent at a dose 10µg/kg. The results also show that there was a significant reduction (p<0.001) of the population of polymorphonuclear leukocytes from peritoneal cavity in the three tested doses (0.1µg/kg; 1µg/kg and 10µg/kg) when it was compared to the positive control (just thioglycolate). Therefore, since the CST structure and mechanism of action has been completely elucidated, this compound may have potential for therapeutic use in inflammatory diseases

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Subsurface stratigraphic analysis of Devonian strata from the Rio do Peixe Basin, newly recognized by palynological studies, has resulted in the identification of two new lithostratigraphic units assembled in the Santa Helena Group. The Pilões Formation, the lower unit, is composed mainly of dark mudstones and medium-tovery fine-grained sandstones, with minor conglomerates and breccias. The Triunfo Formation, the upper unit, comprises whitish grey, kaolinitic, coarse-grained to conglomeratic, cross stratified sandstones and conglomerates, with interbedded mudstones and fine-grained sandstones. These units were characterized using cores, sidewall and cuttings samples, conventional logs and image log, from three wells drilled by PETROBRAS, and 3D seismic data. The Pilões Formation is interpreted as prodeltaic facies, with lesser associated subaqueous talus, debrite and sandy turbidite lobe facies, distal part of fandelta and braided fluviodeltaic facies of Triunfo Formation. The Santa Helena Group corresponds to the Lower Devonian tectono-sequence deposited in a NW-SE-trending graben during a transgressiveregressive cycle. With 343 meters of thickness (isochore) in well 1-PIL-1-PB (Pilões 1), this sequence has a non-conformity at the lower boundary and its upper boundary is an unconformity with the Lower Cretaceous tectono-sequence (Rio do Peixe Group), that represents a hiatus of about 265 million years. Ignimbrites and coignimbrite breccias (Poço da Jurema volcanic breccia), related to an unknown pyroclastic volcanic event, were recognized at the northern margin of the Sousa halfgraben. Evidence from well data suggests that this event is coeval with the Devonian graben filling. The present study indicates a polyhistorical tectono-volcanosedimentary evolution of the basin. This lithostratigraphic update brings new perspectives for geological research in the Rio do Peixe Basin, as well as in other inland basins of the Northeastern of Brazil. The results of the research also contribute to the kwnoledge of the Borborema Province and western Gondwana paleogeography during the Early Devonian.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Technical and interpretative aspects of the String Quartet No. 2 Guerra-Peixe will approach this work of a composer who is considered one of the greatest exponents of Brazilian music of the twentieth century, who developed several strands in his career as a musicologist, performer, composer, arranger radio and cinema, among others. In this work, we will see in the work in question their compositional styles, pointing sources that he has been drinking and offering elements that will subsidize technical and interpretive choices for future interpreters. After the historical context and esthetics, we will make some brief remarks about the terms performance and interpretation, to support the objective of the work, which will be the interpretation of the work. For that purpose, a comparative analysis was performed between recording of important Brazilian quartets, interviews with relevant players on the national scene and trials in rehearsals and recitals, always making a Quartet bridge with other works by the composer. Concomitantly, it was held analysis of handwritten edits by the composer, culminating with its own revised edition.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Technical and interpretative aspects of the String Quartet No. 2 Guerra-Peixe will approach this work of a composer who is considered one of the greatest exponents of Brazilian music of the twentieth century, who developed several strands in his career as a musicologist, performer, composer, arranger radio and cinema, among others. In this work, we will see in the work in question their compositional styles, pointing sources that he has been drinking and offering elements that will subsidize technical and interpretive choices for future interpreters. After the historical context and esthetics, we will make some brief remarks about the terms performance and interpretation, to support the objective of the work, which will be the interpretation of the work. For that purpose, a comparative analysis was performed between recording of important Brazilian quartets, interviews with relevant players on the national scene and trials in rehearsals and recitals, always making a Quartet bridge with other works by the composer. Concomitantly, it was held analysis of handwritten edits by the composer, culminating with its own revised edition.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

This work is aimed at providing an interpretive study of the work for viola and piano titled Three Pieces, and work for solo viola titled Ticket of a Jogral, by Brazilian composer César Guerra Peixe. This study will be divided into three parts: The first will bring a brief history of the composer focusing on his visit to Pernambuco in the late 1940s and early 1950s; the second shows the use of Pernambuco musical regionalism elements used by the composer in the aforementioned documents; the third will present a set of interpretive suggestions based: the analysis of regional musical elements identified in these works; the technical rudiments used in writing for viola depicting the arcades, dynamics, fingerings, articulations, phrasing; and the experiences lived by the author of this research as an interpreter of these works.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

This work is aimed at providing an interpretive study of the work for viola and piano titled Three Pieces, and work for solo viola titled Ticket of a Jogral, by Brazilian composer César Guerra Peixe. This study will be divided into three parts: The first will bring a brief history of the composer focusing on his visit to Pernambuco in the late 1940s and early 1950s; the second shows the use of Pernambuco musical regionalism elements used by the composer in the aforementioned documents; the third will present a set of interpretive suggestions based: the analysis of regional musical elements identified in these works; the technical rudiments used in writing for viola depicting the arcades, dynamics, fingerings, articulations, phrasing; and the experiences lived by the author of this research as an interpreter of these works.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Substâncias psicoestimulantes vêm sendo utilizadas de forma indiscriminada há muitos anos, e pouco se sabe os efeitos que elas causam a curto e longo prazo no comportamento geral, na aprendizagem e na memória. Essas substâncias são bastante usadas por jovens e adultos e elas possuem efeitos diferentes. Essas substâncias são dose dependente, caso consumidas em baixa quantidade agem como estimulante, aumentando a atividade locomotora, caso consumidas em alta quantidade, causam efeito depressor, diminuindo a atividade locomotora e/ou causando ansiedade. Poucos estudos vêm investigando os efeitos dessas substâncias na atividade locomotora, aprendizagem e memória e grande parte desses estudos são realizados em roedores. Peixe paulistinha é um modelo animal promissor para estudos comportamentais, cognitivos, ontogenéticos, dentre outros. Nossos objetivos foram determinar os efeitos do álcool, cafeína e de seu uso combinado com álcool, na atividade locomotora desses animais, usando para isso doses crônicas durante 27 dias e doses agudas durante um dia. Visto que pouco se sabe sobre os efeitos dessa exposição prolongada. Também investigamos os efeitos das substâncias em teste de reconhecimento de objetos, que se baseia na memória de único evento. Essas memórias são mais vulneráveis que memórias baseadas em várias repetições de eventos. Sendo assim, um teste adequado para utilizar com uso de substâncias psicoativas. Observamos que o uso crônico de cafeína provoca alteração na atividade locomotora dos animais, do mesmo modo, abstinência de álcool combinada com cafeína em dose aguda (dose média) provoca aumento de atividade locomotora. Quando submetidos a testes de memória, os animais exposto a doses altas agudas de álcool e em abstinência dessa droga têm prejuízo na formação e/ou resgate da memória. No entanto, tratamento com cafeína não prejudica a formação de memória. Animais expostos a tratamento com dose crônica moderada de álcool e dose aguda moderada de cafeína tem melhor desempenho na tarefa, indicando que dose aguda moderada de cafeína pode evitar os efeitos deletérios ocasionados pela abstinência do álcool. Em termos do comportamento geral, doses agudas de cafeína aumentam a locomoção, enquanto doses elevadas e a abstinência de cafeína induzem a comportamentos tipo-ansioso. A combinação álcool crônico e cafeína aguda induzem a alto comportamento tipo-ansiedade, enquanto a combinação cafeína crônica e álcool agudo diminuem tanto a locomoção quanto a ansiedade.