Navegando por Palavras-chave "Oreochromis niloticus"
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- ItemSomente MetadadadosAggressive behaviour traits predict physiological stress responses in Nile tilapia (Oreochromis niloticus)(Taylor & Francis Ltd, 2009-03-01) Barreto, Rodrigo Egydio; Volpato, Gilson Luiz; Faturi, Claudia de Brito [UNIFESP]; Giaquinto, Percilia Cardoso; Freitas, Eliane Goncalves de; Castilho, Marisa Fernandes de; RECAW; Universidade de São Paulo (USP); Universidade Federal de São Paulo (UNIFESP); UNESP; Universidade Federal do Paraná (UFPR)This study tested whether aggressive behaviour can predict individual variation in stress responses of Nile tilapia Oreochromis niloticus. We used a mirror test to measure tendency to aggressive behaviour, and calculated the attack frequency and time until the first attack (latency) for each fish. One day later, we measured plasma cortisol and glucose, and two days later, we measured ventilatory frequency (VF) (pre-confinement responses). Immediately after the VF measure, we subjected the same fish to 30 min confinement, followed by measurements of cortisol, glucose, and VF (post-confinement responses). We found that post-confinement stress cortisol, glucose, and VF were higher than pre-confinement responses. Attack frequency was negatively correlated with VF and latency was positively correlated with baseline glucose and VF. Thus, we conclude that attack frequency and latency to a mirror reflection could be used to predict baseline levels of physiological stress indicators in Nile tilapia.
- ItemEmbargoAvaliação do risco de invasão de espécies não-nativas e caracterização histopatológica de peixes da Bacia do Alto Tietê SP, Brasil(Universidade Federal de São Paulo, 2023-12-13) Valle, Amanda de Azevedo [UNIFESP]; Azevedo, Juliana de Souza [UNIFESP]; http://lattes.cnpq.br/9196997953777495; https://lattes.cnpq.br/4661034322104934The introduction of species is a global problem. In the context of aquaculture, introductions into watersheds located in urbanized areas deserve special attention. Although the dangers of this introduction are recognized, there is still a significant lack of studies on invasions in urbanized reservoirs. In this context, this research aimed to assess the risk of invasion by non-native freshwater species in the Alto Tietê Hydrographic Basin (BH-AT), kept in fishing grounds in the extreme south of São Paulo. The risk of invasion was assessed using the Aquatic Species Invasiveness Screening Kit (AS-ISK) software version 2.3, a protocol for deciding on the impact of invasive species. The categorization covers 1) Biogeography/History; 2) Biology/Ecology; and 3) Climate Change, to provide quantitative results. The risk of invasion was categorized in the Basic Risk Assessment (BRA) scenario and the risk scenario associated with Climate Change (BRA+CCA), as follows for the BRA scenario: <1 = low risk of invasion; 1 - 21.9 = medium risk; >21.9 = high risk. In turn, perception data was obtained from interventions in the field, using a semi-structured form and through the collection of secondary bio-ecological data. In addition, the health of the fish was checked through histopathological evaluation of the liver tissue of Oreochromis niloticus, a species commonly found in all fishing grounds in the region. About the invasion potential for the Basic Risk Assessment, medium invasive potential was found for Cyphochrax modestus (BRA = 5), Astyanax fasciatus (BRA = 10), Hypostomus ancistroides (BRA = 18), Geophagus brasiliensis (BRA = 21) and Hoplias malabaricus (BRA = 21) and high invasive potential for Colossoma macropomum (BRA = 22), Rhamdia quelen (BRA = 28), Synbranchus marmoratus (BRA = 28), Piaractus mesopotamicus (BRA = 29), Crenicichla lenticulata (BRA = 31), Oreochromis niloticus (BRA = 31), Pseudoplatystoma fasciatum (BRA = 35), Salminus sp. (BRA = 35), Pseudoplatystoma corruscans (BRA = 37), Copton rendalli (BRA = 37), Cyprinus carpio (BRA = 45) and Clarias gariepinus (BRA = 59). In addition, data indicates that the species cultivated are likely to come from inland farms in the municipalities of São Paulo and Minas Gerais. In this sense, the compilation of data, together with the risk assessment, indicates that the fishing grounds of the BH-AT are potential dispersers of exotic, potentially invasive species.
- ItemAcesso aberto (Open Access)Cytochemical aspects of the peripheral blood cells of Oreochromis (Tilapia) niloticus. (Linnaeus, 1758) (Cichlidae, Teleostei): part II(Faculdade de Medicina Veterinária e Zootecnia / Universidade de São Paulo, 2001-01-01) Ueda, Ivete Kotomi [UNIFESP]; Egami, Mizue Imoto [UNIFESP]; Sasso, Wilson da Silva [UNIFESP]; Matushima, Eliana Reiko; Universidade Federal de São Paulo (UNIFESP); Universidade de São Paulo (USP)Morphologicaly, seven types of cells were identified in the blood of Oreochromis niloticus: erythrocytes, thrombocytes, neutrophils, eosinophils, basophils, lymphocytes and monocytes. Glycogen was present not only in the cytoplasm of neutrophils and thrombocytes but also in some lymphocytes and monocytes. The positive reaction for myeloperoxidase and Sudan black was observed in neutrophils and eosinophils. The bromphenol blue method was strongly positive for erythrocytes and eosinophils.