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Conservação de filés de tilápia-do-nilo (Oreochromis niloticus) em salga seca e salga úmida; Nile tilapia (Oreochromis niloticus) preservation by means of dry salting and saturated brine

AIURA, F.S.; CARVALHO, M.R.B.; VIEGAS, E.M.M.; KIRSCHNIK, P.G.; LIMA, T.M.A.
Fonte: Universidade Federal de Minas Gerais, Escola de Veterinária Publicador: Universidade Federal de Minas Gerais, Escola de Veterinária
Tipo: Artigo de Revista Científica
POR
Relevância na Pesquisa
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Acompanhou-se o desenvolvimento dos processos da salga em salmoura saturada (salga úmida) e salga seca de filés de tilápia-do-nilo (Oreochromis niloticus) e avaliaram-se algumas características indicativas de qualidade do produto durante a estocagem. Os processos foram acompanhados por 156 horas na salga úmida e por 96 horas na salga seca, e os filés salgados foram estocados, respectivamente, por 60 e 45 dias à temperatura ambiente. Os teores máximos de cloreto nos filés (14%) foram atingidos com 72 horas na salga úmida e com 36 horas na salga seca. Os filés de tilápia salgados em salmoura mantiveram as características próprias do produto por um período de 45 dias, e os submetidos à salga seca apresentaram baixo teor de umidade (6%) e alta concentração de extrato etéreo (4,6%). Recomenda-se somente o processo de salga em salmoura saturada como forma de conservação dos filés de tilápia-do-nilo.; The processes of salting of Nile tilapia fillets (Oreochromis niloticus) submitted to saturated brine and dry salting were observed, and some characteristics that indicate the quality of the product during the storage were evaluated. The brine saturated process was followed up to 156 hours and the dry salting was followed up to 96 hours. When the salting finished...

The `club` cell and behavioural and physiological responses to chemical alarm cues in the Nile tilapia

BARRETO, Rodrigo Egydio; BARBOSA JUNIOR, Augusto; GIASSI, Ana Catarina Casari; HOFFMANN, Anette
Fonte: TAYLOR & FRANCIS LTD Publicador: TAYLOR & FRANCIS LTD
Tipo: Artigo de Revista Científica
ENG
Relevância na Pesquisa
67.05%
The alarm response to skin extract has been well documented in fish. In response to skin extract, there is a decline in both locomotion activity and aggressive interactions. Our observation herein of these responses in the cichlid Nile tilapia, Oreochromis niloticus, confirmed the existence of the alarm response in this species. However, so far there has been a paucity of information on the autonomic correlates of this response. In this study, the ventilatory change in response to the chemical alarm cue was evaluated. This parameter was measured 4 min before and 4 min after exposure to 1 mL of either conspecific skin extract or distilled water (extract vehicle). Skin extract induced an increase in the ventilation rate, which suggested an anticipatory adjustment to potentially harmful stimuli. The chemical cue (alarm substance) also interfered with the prioritisation of responses to different environmental stimuli (stimuli filtering); this was suggested by the observation that the Nile tilapia declined to fight after exposure to a cue that indicates a risk of predation. Furthermore, histological analysis of the Nile tilapia skin revealed the presence of putative alarm substance-producing (club) cells.; Universidade de São Paulo - FMRP-USP; Fundacao de Amparo a Pesquisa do Estado de Sao Paulo-FAPESP[2005/04771-5]

Digestive enzyme activity in juvenile Nile tilapia (Oreochromis niloticus, L) submitted to different dietary levels of shrimp protein hydrolysate

Santos, Juliana Ferreira; Castro, Patrícia Fernandes; Leal, Albino Luciani Gonçalves; Freitas Júnior, Augusto Cézar Vasconcelos de; Lemos, Daniel Eduardo Lavanholi de; CarvalhoJr, Luiz Bezerra; Bezerra, Ranilson Souza
Fonte: Dordrecht Publicador: Dordrecht
Tipo: Artigo de Revista Científica
ENG
Relevância na Pesquisa
67.05%
The effect of different dietary concentrations of shrimp protein hydrolysate (SPH) on digestive enzyme activity of Nile tilapia juveniles was evaluated. SPH concentrations in diets were 0, 15, 30 and 60 g kg−1 (treatments SPH0, SPH15, SPH30 and SPH60, respectively). Hemoglobin, azocasein, BApNA (Nα-benzoyl-dl-arginine-p-nitroanilide), SApNA (Suc-Ala-Ala-Pro-Phe p-nitroanilide), aminoacyl of β-naphthylamide and starch were used as substrates for enzyme activity determinations. The activity of total alkaline protease was significantly higher (P < 0.05) in fish under SPH15 and SPH60 treatments than in the control (SPH0). However, the effect was not dose-dependent. Substrate-SDS-PAGE was also performed to evaluate changes in the profile of Nile tilapia digestive proteases caused by SPH. Substrate-SDS-PAGE revealed 12 active proteolytic bands, eight of which responded to SPH dietary incorporation. Inhibition substrate-SDS-PAGE indicated a decrease in the activity of three enzymes, with trypsin activity decreasing with the increase of SPH concentration, whereas the opposite occurred for two aminopeptidases. Distinct protease profiles were also found for each treatment, suggesting adaptability of digestive proteases from Nile tilapia to the different diets.; Fundação de Apoio à Ciência e Tecnologia do Estado de Pernambuco (FACEPE); FAPESP - 05/50578-2; FAPESP - 07/07051-9; CNPq/SEAP - 504031/03-1; CNPq/SEAP - 308444/06-0; CNPq/SEAP - 474222/07

Aproveitamento do resíduo do beneficiamento da Tilápia do Nilo (Oreochromis niloticus) para obtenção de silagem e óleo como subprodutos.; Utilization of fish waste from the processing of nile tilapia (Oreochromis niloticus) to obtain fish silage and fish oil as by-products.

Arruda, Lia Ferraz de
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Dissertação de Mestrado Formato: application/pdf
Publicado em 27/08/2004 PT
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Um terço da captura mundial de pescado não é empregada para o consumo direto na alimentação humana, seguindo para elaboração de rações ou é desperdiçada como resíduo. O ideal seria utilizar a matéria-prima em toda a sua extensão e recuperar os subprodutos, evitando a própria formação do resíduo. Com os objetivos de aumentar a receita e a eficiência de produção da indústria e, conseqüentemente, minimizar os problemas ambientais e de sanidade, provenientes do resíduo de pescado, procedeu-se à elaboração da silagem química do resíduo de beneficiamento da tilápia. A tilápia do Nilo (Oreochromis niloticus) é hoje a espécie mais popular no Brasil. A tilápia é cultivada em 22 estados brasileiros e a sua produção anual está entre 30 e 40 mil t. A tilápia foi uma das primeiras espécies oriundas da aqüicultura a ser beneficiada, sendo atualmente comercializada na forma de filés congelados, tecnologia emergente, porém com rendimento de cerca de 30%. Com isso, há necessidade de se transformar o resíduo gerado com o beneficiamento do filé em subprodutos, diminuindo o impacto ambiental. A silagem foi elaborada após homogeneização em cutter e acidificação da biomassa com 3% de ácido fórmico: propiônico...

Avaliação físico-química, nutricional e biológica das silagens ácida, biológica e enzimática elaboradas com descarte e resíduo do beneficiamento da Tilápia do Nilo (Oreochromis niloticus).; Physical-chemical, nutritional and biological evaluation of acid, biological and enzymatic silage made from trash fish and fish waste from the processing of Nile tilapia (Oreochromis niloticus).

Borghesi, Ricardo
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Dissertação de Mestrado Formato: application/pdf
Publicado em 16/08/2004 PT
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No Brasil e no mundo, a indústria relacionada à pesca gera grande quantidade de resíduo de alto valor biológico. Este material residual, devido a falta de um destino adequado, é considerado um problema sob o ponto de vista ambiental, de sanidade e de eficiência de produção. Com os objetivos de minimizar os problemas ambientais e melhorar a eficiência de produção da indústria do pescado, procedeu-se a elaboração e a caracterização físico-química e nutricional da silagem ácida (SA), silagem biológica (SB) e silagem enzimática (SE), utilizando como matéria-prima os descartes da piscicultura e o resíduo do beneficiamento da tilápia do Nilo (Oreochromis niloticus) (Experimento 1). As silagens SA, SB e SE apresentaram os valores (base na matéria seca) de: 25,21; 34,58 e 25,01 g/100g para a matéria seca, 54,25; 33,00 e 54,50 g/100g para a proteína bruta, 12,45; 12,25 e 12,17 g/100g para lipídios, 8,03; 7,33 e 8,58 g/100g para o cálcio e 4,71; 2,86 e 4,85 g/100g para o fósforo, respectivamente. Entre os aminoácidos essenciais (AAE), a leucina (3,50; 2,41 e 3,31 g/100g para SA, SB e SE, respectivamente) e a lisina (3,33; 2,41 e 3,22 g/100g para SA, SB e SE, respectivamente) apresentaram-se em maior concentração. Com base no escore químico...

Alterações morfológicas de Tilápias do Nilo (Oreochromis niloticus) (Linnaeus, 1758) expostas às águas da represa Billings.; Morphologic alterations of Nile Tilapia (Oreochromis niloticus) (Linnaeus, 1758) exposed to waters of Billings dam.

Rezende, Karina Fernandes Oliveira
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Dissertação de Mestrado Formato: application/pdf
Publicado em 20/07/2011 PT
Relevância na Pesquisa
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A Represa Billings apresenta águas eutrofizadas em decorrência da grande quantidade de esgoto proveniente da área urbana próxima, e como conseqüência, os peixes podem representar um problema de saúde pública. As brânquias e o fígado tornam-se órgãos alvo para a ação dos poluentes existentes no meio aquático podendo se manifestar em vários níveis de organização biológica. Estas respostas biológicas ao estresse provocado pelos poluentes podem ser utilizadas para identificar sinais iniciais de danos aos peixes e podem ser denominadas biomarcadores. Desse modo, o presente projeto teve como objetivo a análise histológica de brânquias e fígado de Tilápias do Nilo, por meio de mensurações, Índice de Alterações Histológicas e Valor Médio de Avaliação; também foi realizada a análise da freqüência de micronúcleo. Verficou-se que as Tilápias do Nilo apresentam alterações histológicas das brânquias e do fígado classificadas como moderada a grave, além da presença de micronúcleo. Os resultados permitem um melhor monitoramento ambiental e o controle da qualidade dessa espécie.; The Billings dam shows eutrophic waters due to the large amount of sewage from urban occupation neaby, and consequently...

Estudo de Tilápias do Nilo (Oreochromis niloticus) como bioindicadores da poluição por mercúrio nos lagos do Parque Ibirapuera e do Parque Ecológico do Tietê na Grande São Paulo; Study on Nile Tilapia (Oreochromis niloticus) as mercury pollution bioindicators at Parque Ibirapuera and Parque Ecológico do Tietê lakes at Greater São Paulo

Carretero, Maria Eugenia
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Dissertação de Mestrado Formato: application/pdf
Publicado em 17/12/2012 PT
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A Grande São Paulo, composta por 39 municípios, apresenta crescimento urbano e industrial expoente que contribuem para o constante acúmulo de poluentes no ambiente. Ainda assim, exibe áreas verdes remanescentes que contribuem para a sustentabilidade ambiental da cidade, como por exemplo, o Parque Ibirapuera e o Parque Ecológico do Tietê. Nesse contexto, o presente estudo visa verificar a viabilidade em utilizar as O. niloticus como bioindicadoras da poluição por mercúrio no ecossistema aquático dos dois parques da Grande São Paulo. Obteram-se para as tilápias do Nilo do Parque Ibirapuera pertencentes aos pontos de coleta A, B e C durante o inverno as respectivas concentrações de mercúrio total no sangue 2,72±4,20µg/L, 2,45±1,90µg/L e 1,19±0,05µg/L e, no hepatopâncreas as respectivas concentrações de mercúrio de 0,07±0,02 µg/g, 0,06 ±0,005 µg/g e 0,16 ±0,07 µg/g. No verão as tilápias do Parque Ibirapuera apresentaram nos mesmos pontos de coleta as respectivas concentrações de mercúrio total no sangue 2,50±0,84µg/L, 2,67±1,03µg/L e 2,430±0,790µg/L e, no hepatopâncreas as respectivas concentrações de mercúrio de 0,08 ±0,03 µg/L, 0,16 ±0...

Análise de parabenos em amostras de água de cultivo de tilápia do Nilo (Oreochromis niloticus) e efeitos em biomarcadores bioquímicos; Parabens analysis in water samples with nile tilapia (Oreochromis niloticus) and effects in biochemical biomarkers

Silva, Daniele Caetano da
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Tese de Doutorado Formato: application/pdf
Publicado em 13/07/2015 PT
Relevância na Pesquisa
67%
Os parabenos utilizados como conservantes nas indústrias de cosméticos, alimentos e fármacos não são removidos por completo nas estações de tratamento de água e esgoto, além disso, podem causar danos a biota aquática. O presente estudo teve como finalidade aplicar um método analítico novo para quantificar o metil (MP), etil (EP), propil (PP), butil (BP), benzilparabeno (BzP) e a mistura (metil e propilparabeno) em amostras de água dos aquários com tilápias do Nilo (Oreochromis niloticus). A técnica analítica usada foi a cromatografia líquida com detector de arranjo de diodo (HPLC-DAD). Avaliou-se a toxicidade dos parabenos em tilápias e os efeitos nos biomarcadores bioquímicos dos animais após 6 e 12 dias dos testes de exposição e por administração via injeção intraperitoneal. A concentração dos parabenos utilizada em todos os testes foi de 4,0 mg L-1 (de cada parabeno individualmente) e de 6,0 mg L-1 do metil e de 1,7 mg L-1 do propilparabeno para a mistura. Foram feitas análises nos biomarcadores superóxido dismutase (SOD), catalase (CAT), glutationa peroxidase (GPx), glutationa redutase (GR), glutationa reduzida(GSH-t) e peroxidação lipídica (MDA). O limite de detecção dos parabenos foi de 0,03 mg L-1 (MP e EP)...

Validation of the aceto-carmine technique for evaluating phenotypic sex in Nile tilapia (Oreochromis niloticus) FRY; Validação da técnica do aceto-carmim para avaliar o sexo de alevinos de tilápia nilótica (Oreochromis niloticus)

Wassermann, Gustavo Javier; Afonso, Luis Orlando Bertolla
Fonte: Universidade Federal do Rio Grande do Sul Publicador: Universidade Federal do Rio Grande do Sul
Tipo: Artigo de Revista Científica Formato: application/pdf
ENG
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Neste estudo foi validado um método para avaliar o sexo fenotípico de alevinos de tilápia nilótica. Foi comparada uma técnica que usa aceto-carmim para corar o tecido gonadal, o qual é examinado em microscópio, com a histologia tradicional. Aproximadamente 2600 alevinos de tilápia nilótica com idade entre 35 e 60 dias após a eclosão (DAE), pesando e medindo, respectivamente, 0,250-2,50g and 26-53mm foram sexados usando este método. Foi também realizado um exame macroscópico das gonadas in situ. Foi possivel sexar com acerto, usando o método de aceto-carmim, alevinos com peso superior a 0.50g, 45-47 DAE. Os resultados das observações microscópicas usando o corante aceto-carmim coincidiram em 100% com o exame histológico. O tecido gonadal dos machos foi caracterizado pela presenca de cistos que continham espermatogônias e espermatócitos, enquanto que as fêmeas foram facilmente identificadas pela presenca de ovócitos no estádio perinucleolar. A técnica provou ser eficiente não só para avaliar a proporção dos sexos, mas também porque permite avaliação imediata do sexo gonadal e demanda menos tempo e trabalho.; In this study a method for evaluating phenotypic sex in Nile tilapia was validated. A technique that uses aceto-carmine squash mounts to stain the entire gonadal tissue for microscopic examination (Method 2- squash mounts) was compared with a technique based on traditional histology. Approximately 2600 Nile tilapia fry weighing and measuring...

Sex-specific compensatory growth in food-deprived Nile tilapia

Barreto, R.E.; Moreira, P.S.A.; Carvalho, R.F.
Fonte: Associação Brasileira de Divulgação Científica (ABRADIC) Publicador: Associação Brasileira de Divulgação Científica (ABRADIC)
Tipo: Artigo de Revista Científica Formato: 477-483
ENG
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Female Nile tilapia incubate fertilized eggs in their mouth until they are released as alevins. Consequently, the female may not eat during this period. Thus, it would be expected that female Nile tilapia are more adapted to recovering from fasting than males, which do not display this behavior. To test this hypothesis we conducted an experiment with two groups of fish consisting of 7 males and 7 females each, with one fish per aquarium. The experiment was divided into three phases involving adjustment of the animals to experimental aquaria (0-15th day), fasting (16th-27th day), and refeeding (27th-42nd day). Compensatory growth performance was assessed by specific growth rate, weight, food conversion efficiency and food intake. Food conversion efficiency increased after fasting with a similar rate for both sexes. However, specific growth rate, food intake and weight gain (%) were significantly higher in males than in females in the refeeding phase. Thus, we conclude that male Nile tilapia can compensate for a fasting period more efficiently than females, refuting our hypothesis. A possible mechanism involved in the greater male compensation is that they presented greater hyperphagia than females, concomitantly with a similar rate of food conversion efficiency for both sexes during refeeding...

Identities among actin-encoding cDNAs of the Nile tilapia (Oreochromis nildticus) and other eukaryote species revealed by nucleotide and amino acid sequence analyses

Poletto, Andreia B.; Wasko, Adriane Pinto; Oliveira, Claudio; Azevedo, Alexandre; Carvalho, Robson F.; Silva, Maeli Dal Pai; Foresti, Fausto; Martins, Cesar
Fonte: Soc Brasil Genetica Publicador: Soc Brasil Genetica
Tipo: Artigo de Revista Científica Formato: 352-356
ENG
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Actin-encoding cDNAs of Nile tilapia (Oreochromis niloticus) were isolated by RT-PCR using total RNA samples of different tissues and further characterized by nucleotide sequencing and in silico amino acid (aa) sequence analysis. Comparisons among the actin gene sequences of O. niloticus and those of other species evidenced that the isolated genes present a high similarity to other fish and other vertebrate actin genes. The highest nucleoticle resemblance was observed between O. niloticus and O. mossambicus a-actin and P-actin genes. Analysis of the predicted aa sequences revealed two distinct types of cytoplasmic actins, one cardiac muscle actin type and one skeletal muscle actin type that were expressed in different tissues of Nile tilapia. The evolutionary relationships between the Nile tilapia actin genes and diverse other organisms is discussed.

Physical mapping of the Nile tilapia (Oreochromis niloticus) genome by fluorescent in situ hybridization of repetitive DNAs to metaphase chromosomes - a review

Martins, C.; Oliveira, C.; Wasko, A. P.; Wright, J. M.
Fonte: Elsevier B.V. Publicador: Elsevier B.V.
Tipo: Artigo de Revista Científica Formato: 37-49
ENG
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The Nile tilapia (Oreochromis niloticus) has received increasing scientific interest over the past few decades for two reasons: first, tilapia is an enormously important species in aquaculture worldwide, especially in regions where there is a chronic shortage of animal protein; and second, this teleost fish belongs to the fascinating group of cichlid fishes that have undergone a rapid and extensive radiation of much interest to evolutionary biologists. Currently, studies based on physical and genetic mapping of the Nile tilapia genome offer the best opportunities for applying genomics to such diverse questions and issues as phylogeography, isolation of quantitative trait loci involved in behaviour, morphology, and disease, and overall improvement of aquacultural stocks. In this review, we have integrated molecular cytogenetic data for the Nile tilapia describing the chromosomal location of the repetitive DNA sequences, satellite DNAs, telomeres, 45S and 5S rDNAs, and the short and long interspersed nucleotide elements [short interspersed nuclear elements (SINEs) and long interspersed nuclear elements (LINEs)], and provide the beginnings of a physical genome map for this important teleost fish. (C) 2004 Elsevier B.V. All rights reserved.

Identities among actin-encoding cDNAs of the Nile tilapia (Oreochromis niloticus) and other eukaryote species revealed by nucleotide and amino acid sequence analyses

Poletto, Andréia B.; Wasko, Adriane Pinto; Oliveira, Claudio; Azevedo, Alexandre; Carvalho, Robson F.; Silva, Maeli Dal Pai; Foresti, Fausto; Martins, Cesar
Fonte: Sociedade Brasileira de Genética Publicador: Sociedade Brasileira de Genética
Tipo: Artigo de Revista Científica Formato: 325-356
ENG
Relevância na Pesquisa
67.05%
Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP); Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq); Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES); Actin-encoding cDNAs of Nile tilapia (Oreochromis niloticus) were isolated by RT-PCR using total RNA samples of different tissues and further characterized by nucleotide sequencing and in silico amino acid (aa) sequence analysis. Comparisons among the actin gene sequences of O. niloticus and those of other species evidenced that the isolated genes present a high similarity to other fish and other vertebrate actin genes. The highest nucleotide resemblance was observed between O. niloticus and O. mossambicus a-actin and b-actin genes. Analysis of the predicted aa sequences revealed two distinct types of cytoplasmic actins, one cardiac muscle actin type and one skeletal muscle actin type that were expressed in different tissues of Nile tilapia. The evolutionary relationships between the Nile tilapia actin genes and diverse other organisms is discussed.

Use of ideal protein concept for precision formulation of amino acid levels in fish-meal-free diets for juvenile Nile tilapia (Oreochromis niloticus L.)

Furuya, W. M.; Pezzato, L. E.; Barros, M. M.; Pezzato, A. C.; Furuya, VRB; Miranda, E. C.
Fonte: Blackwell Publishing Publicador: Blackwell Publishing
Tipo: Artigo de Revista Científica Formato: 1110-1116
ENG
Relevância na Pesquisa
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This study was undertaken in a closed system with Nile tilapia (Oreochromis niloticus) to examine the effects of total replacement of fish meal (FM) by soybean meal. Nile tilapia fingerlings with an average weight of 5.34+/-0.08 g were hand-fed one of the five isoenergetic (approximate to13.5 MJ digestible energy kg(-1)) and isoproteic (approximate to31% of digestible protein) experimental diets to satiation, six times a day during 85 days in eight replicate fibreglass tanks (six fish per tank). The control diet containing FM was substituted by soybean meal, with and without essential amino acids (lysine, methionine and threonine) or dicalcium phosphate supplementation. The supplemental amino acids were added at levels to simulate the reference amino acid profile of Nile tilapia carcass protein, based on the ideal protein concept. The results showed that soybean meal diet supplemented only with dicalcium phosphate was inferior to the control diet with FM and soybean meal diets supplemented with dicalcium phosphate and essential amino acids. Multiple essential amino acids and dicalcium phosphate incorporation in soybean meal diets was associated with performance, whole-body composition and carcass yield equal to that of the fish fed with the control diet containing FM. These data suggest that a diet with all plant protein source...

A place preference test in the fish Nile tilapia

Delicio, Helton Carlos; Barreto, Rodrigo Egydio; Normandes, Edvaldo Bento; Luchiari, Ana Carolina; Marcondes, Ana Lúcia
Fonte: Universidade Estadual Paulista Publicador: Universidade Estadual Paulista
Tipo: Artigo de Revista Científica Formato: 141-148
ENG
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The Nile tilapia fish (Oreochromis niloticus) has a high potential to be used as a model in neuroscience studies. In the present study, the preference of the Nile tilapia between a gravel-enriched (GEE), a shelter-enriched (SEE) or a non-enriched (NEE) environment was determined, for developing a place preference model. Nile tilapia had an initial preference for GEE, but after 1 day of observation, the fish stabilized their frequency of visits among compartments. Hence, any stimulus motivating tilapia increase in compartment visiting indicates a positively reinforcing effect. This feature is very useful for the development of new behavioural paradigms for fish in tests using environmental discrimination, such as the conditioning place preference test. © 2006 Elsevier GmbH. All rights reserved.

Biochemical biomarkers in Nile tilapia (Oreochromis niloticus) after short-term exposure to diesel oil, pure biodiesel and biodiesel blends

Nogueira, Lílian; Sanches, Ana Letícia Madeira; da Silva, Danilo Grünig Humberto; Ferrizi, Vítor Cid; Moreira, Altair Benedito; de Almeida, Eduardo Alves
Fonte: Universidade Estadual Paulista Publicador: Universidade Estadual Paulista
Tipo: Artigo de Revista Científica Formato: 97-105
ENG
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Fossil fuels such as diesel are being gradually replaced by biodiesel, a renewable energy source, cheaper and less polluting. However, little is known about the toxic effects of this new energy source on aquatic organisms. Thus, we evaluated biochemical biomarkers related to oxidative stress in Nile tilapia (Oreochromis niloticus) after two and seven exposure days to diesel and pure biodiesel (B100) and blends B5 and B20 at concentrations of 0.01 and 0.1mLL -1. The hepatic ethoxyresorufin-O-deethylase activity was highly induced in all groups, except for those animals exposed to B100. There was an increase in lipid peroxidation in liver and gills in the group exposed to the higher concentration of B5. All treatments caused a significant increase in the levels of 1-hydroxypyrene excreted in the bile after 2 and 7d, except for those fish exposed to B100. The hepatic glutathione-S-transferase increased after 7d in animals exposed to the higher concentration of diesel and in the gill of fish exposed to the higher concentration of pure diesel and B5, but decreased for the two tested concentrations of B100. Superoxide dismutase, catalase and glutathione peroxidase also presented significant changes according to the treatments for all groups...

Sex-specific compensatory growth in food-deprived Nile tilapia

Barreto,R.E.; Moreira,P.S.A.; Carvalho,R.F.
Fonte: Associação Brasileira de Divulgação Científica Publicador: Associação Brasileira de Divulgação Científica
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/04/2003 EN
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Female Nile tilapia incubate fertilized eggs in their mouth until they are released as alevins. Consequently, the female may not eat during this period. Thus, it would be expected that female Nile tilapia are more adapted to recovering from fasting than males, which do not display this behavior. To test this hypothesis we conducted an experiment with two groups of fish consisting of 7 males and 7 females each, with one fish per aquarium. The experiment was divided into three phases involving adjustment of the animals to experimental aquaria (0-15th day), fasting (16th-27th day), and refeeding (27th-42nd day). Compensatory growth performance was assessed by specific growth rate, weight, food conversion efficiency and food intake. Food conversion efficiency increased after fasting with a similar rate for both sexes. However, specific growth rate, food intake and weight gain (%) were significantly higher in males than in females in the refeeding phase. Thus, we conclude that male Nile tilapia can compensate for a fasting period more efficiently than females, refuting our hypothesis. A possible mechanism involved in the greater male compensation is that they presented greater hyperphagia than females, concomitantly with a similar rate of food conversion efficiency for both sexes during refeeding...

Identities among actin-encoding cDNAs of the Nile tilapia (Oreochromis niloticus) and other eukaryote species revealed by nucleotide and amino acid sequence analyses

Poletto,Andréia B.; Wasko,Adriane P.; Oliveira,Claudio; Azevedo,Alexandre; Carvalho,Robson F.; Silva,Maeli Dal Pai; Foresti,Fausto; Martins,Cesar
Fonte: Sociedade Brasileira de Genética Publicador: Sociedade Brasileira de Genética
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/01/2008 EN
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Actin-encoding cDNAs of Nile tilapia (Oreochromis niloticus) were isolated by RT-PCR using total RNA samples of different tissues and further characterized by nucleotide sequencing and in silico amino acid (aa) sequence analysis. Comparisons among the actin gene sequences of O. niloticus and those of other species evidenced that the isolated genes present a high similarity to other fish and other vertebrate actin genes. The highest nucleotide resemblance was observed between O. niloticus and O. mossambicus a-actin and b-actin genes. Analysis of the predicted aa sequences revealed two distinct types of cytoplasmic actins, one cardiac muscle actin type and one skeletal muscle actin type that were expressed in different tissues of Nile tilapia. The evolutionary relationships between the Nile tilapia actin genes and diverse other organisms is discussed.

Reversibility of deleterious effects of the pisciculture byproduct nitrite on cultured nile tilapia (Oreochromis niloticus)

Azevedo, Maristela; Souza, Marta Marques de; Freire, Carolina Arruda
Fonte: Universidade Federal do Rio Grande Publicador: Universidade Federal do Rio Grande
Tipo: Artigo de Revista Científica
ENG
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67.04%
The effects of nitrite (NO2 –) on the Nile tilapia (Oreochromis niloticus) were investigated, due to their relevance to worldwide aquaculture. Hematological parameters – functional haemoglobin (oxy+deoxy-Hb, %), methaemoglobin (MetHb%), and hematocrit (Hct) – and – plasma osmolality, plasma chloride ([Cl−]) and magnesium ([Mg2+]) concentrations – were analysed. Two experiments were conducted, each with its own non-contaminated control, 8 tilapias for each group. In experiment 1 (48 hours), and the first 48 hours of experiment 2, fish were contaminated with 0.4 mM NO2 – (added as NaNO2). In experiment 2, ambient NaNO2 – was removed for the second 48 hours. NaNO2 – exposure increased plasma [NO2 –] to 0.4 mM, which increased MetHb from 10.8 ± 2.5% to 46.8 ± 8.0%, and consequently decreased functional Hb from 89.2 ± 2.5% to 53.2 ± 8.0%. NaNO2 removal led to recovery of both parameters. Both Hct and plasma Mg2+ were lowest in fish recovering from nitrite exposure. Thus, these parameters did not show recovery. Plasma osmolality and [Cl−] were not affected by NaNO2 –, probably due to the moderate rise in plasma [NO2 –]. O. niloticus was thus sensitive to 48 hours of exposure to 0.4 mM NaNO2, and partially recovered from its effects after 48 hours in sodium nitrite-free water. Cultivators of Nile tilapia should thus consider the toxicity of nitrite...

Optimizing an aquaponic system: the effect of pH on Nile tilapia (Oreochromis niloticus) and lettuce-leaf basil (Ocimum basilicum var. crispum) growth

Wang, Miling
Fonte: Quens University Publicador: Quens University
Tipo: Tese de Doutorado
EN
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Aquaponic systems integrate fish and plant production. However, productive conditions required for fish growth can conflict with those required for plant growth. Small-scale indoor aquaponic systems – the integration of fish culture with hydroponic plant production in a recirculating system – were set up for Nile tilapia (Oreochromis niloticus) and lettuce-leaf basil (Ocimum basilicum var. crispum) in the hopes of capitalizing on the effect pH has on the efficiency of ammonia excretion and removal from the system. This study presents such a situation: we hoped to grow larger tilapia at pH 9 but we know that basil grow better at pH 6. The objective of this study was to determine a compromising pH value that would produce the greatest combined yield of tilapia and basil. Tilapia fingerlings and basil plants were stocked for 63 days, at different the pH treatments: 6, 7, 8 and 9. Growth measurement of tilapia was recorded at 14 days intervals. Dry weight was recorded for the basil after the 63 days period. Results showed that tilapia growth performance was significantly decreased at pH 6 and 8 (p<0.05) compared to pH 7 and 9, while the differences between pH 7 and 9 were not significant (p>0.05). Basil growth performance was greatest at pH 6. Supplementary results for tilapia showed that ammonia excretion was significantly lower at pH 9 than pH 8 (p<0.05)...