Metabolic effects in the freshwater fish Geophagus iporangensis in response to single and combined exposure to graphene oxide and trace elements.

Graphene oxide (GO) is part of a new set of nanomaterials with particular characteristics related to its nanoscale size. Due to this feature, it presents high reactivity and other contaminants present in the environment could bind to them and affect its intrinsic toxicity. The metabolic effects of such nanomaterials and their combination with two common pollutants, zinc and cadmium, on the freshwater fish Geophagus iporangensis are analyzed. Moreover, metabolic rate and ammonia excretion were used as bioindicators to measure metabolic changes. Fishes were exposed for 24 h in filtered tap water to different concentrations of GO (0.5; 1.0; 2.0 and 4.0 mg L-1), Zn (0.5; 1.0; 2.0; 4.0 and 10.0 mg L-1) and Cd (0.1; 0.5; 1.0; 2.0 and 4.0 mg L-1). Combined effects were verified using the same concentrations of trace elements added to 1.0 mg L-1 of GO. Exposure to GO and Cd resulted in a decrease of metabolic rate in G. iporangensis, by about 30% compared to control means, in the highest concentration tested (4.0 mg L-1). However, zinc exposure in the highest concentration (10 mg L-1) raised metabolic rate to around three times that of the control group. Ammonia excretion was not affected by exposure to GO and Cd. In contrast, exposure to Zn at 10 mg L-1 raised the rate to around 47%. The combined exposure of GO and Zn intensified the effects of the trace element, inducing responses in both biomarkers at lower concentrations and demonstrating that the interaction between elements increases zinc's effects. The combination Cd + GO only affects metabolic rate. Thus, this metabolic rate alone reveals that combined exposure potentiates effects of trace elements on fish metabolism.

Record of Nile tilapia in the Mandira river, Cananéia, São Paulo state / Registro da tilápia-do-nilo no rio Mandira, Cananéia, estado de São Paulo

The present short communication reports the occurrence of Nile Tilapia (Oreochromis niloticus) in the Mandira River, in the extractive reserve in the Cananéia estuary, São Paulo State. In May 2014, using dip nets, we collected five specimens of O. niloticus in the estuary, with length ranging from 1.4 to 2.5 cm and weight between 0.8 and 2.3 g. Samplings performed in July indicated the presence of additional four specimens of O. niloticus in other stretches of the same river. The occurrence of alien species in conservation areas has high ecological importance, as they can cause environmental and biodiversity alterations; in Brazil, the introduction of alien species is usually related to economic activities, such as the Nile tilapia aquaculture.(AU)

A presente nota registra a ocorrência de tilápia-do-nilo (Oreochromis niloticus) na Reserva Extrativista do Rio Mandira, localizada no munícipio de Cananéia, São Paulo. Em maio de 2014, foram coletados por meio de puçás, cinco exemplares de O. niloticus no estuário, com comprimentos variando entre 1,5 a 2,5 cm e peso entre 0,8 e 2,3 g. Coletas realizadas em julho evidenciaram a presença de mais quatro espécimes de O. niloticus em outros trechos do rio estudado. A ocorrência de espécies exóticas em unidades de conservação é de extrema relevância ecológica, uma vez que pode modificar o ambiente e a biodiversidade de uma região, sendo que no Brasil, a introdução de espécies exóticas encontra-se tipicamente vinculada às atividades de interesse socioeconômico, como é o caso do cultivo de tilápia-do-nilo.(AU)

Record of Nile tilapia in the Mandira river, Cananéia, São Paulo state / Registro da tilápia-do-nilo no rio Mandira, Cananéia, estado de São Paulo

The present short communication reports the occurrence of Nile Tilapia (Oreochromis niloticus) in the Mandira River, in the extractive reserve in the Cananéia estuary, São Paulo State. In May 2014, using dip nets, we collected five specimens of O. niloticus in the estuary, with length ranging from 1.4 to 2.5 cm and weight between 0.8 and 2.3 g. Samplings performed in July indicated the presence of additional four specimens of O. niloticus in other stretches of the same river. The occurrence of alien species in conservation areas has high ecological importance, as they can cause environmental and biodiversity alterations; in Brazil, the introduction of alien species is usually related to economic activities, such as the Nile tilapia aquaculture.

A presente nota registra a ocorrência de tilápia-do-nilo (Oreochromis niloticus) na Reserva Extrativista do Rio Mandira, localizada no munícipio de Cananéia, São Paulo. Em maio de 2014, foram coletados por meio de puçás, cinco exemplares de O. niloticus no estuário, com comprimentos variando entre 1,5 a 2,5 cm e peso entre 0,8 e 2,3 g. Coletas realizadas em julho evidenciaram a presença de mais quatro espécimes de O. niloticus em outros trechos do rio estudado. A ocorrência de espécies exóticas em unidades de conservação é de extrema relevância ecológica, uma vez que pode modificar o ambiente e a biodiversidade de uma região, sendo que no Brasil, a introdução de espécies exóticas encontra-se tipicamente vinculada às atividades de interesse socioeconômico, como é o caso do cultivo de tilápia-do-nilo.

First record of molluscs naturally infected with Angiostrongylus cantonensis (Chen, 1935) (Nematoda: Metastrongylidae) in Brazil.

Seeking the identification of Angiostrongylus cantonensis as a potential etiological agent of three clinical cases of eosinophilic meningitis, mollusc specimens were collected in the state of Espírito Santo, Brazil. The snails were identified as Sarasinula marginata (45 specimens), Subulina octona (157), Achatina fulica (45) and Bradybaena similaris (23). Larvae obtained were submitted to polymerase chain reaction and restriction fragment length polymorphism diagnosis. Their genetic profile were corresponded to A. cantonensis. Rattus norvegicus experimentally infected with third-stage larvae, developed menigoencephalitis, and parasites became sexually mature in the lungs. Additionally, larvae obtained from A. fulica snails, from São Vicente, state of São Paulo, also showed genetic profiles of this nematode. This is the first record of Brazilian molluscs infected with this nematode species.

First record of molluscs naturally infected with Angiostrongylus cantonensis (Chen, 1935) (Nematoda: Metastrongylidae) in Brazil

Seeking the identification of Angiostrongylus cantonensis as a potential etiological agent of three clinical cases of eosinophilic meningitis, mollusc specimens were collected in the state of Espírito Santo, Brazil. The snails were identified as Sarasinula marginata (45 specimens), Subulina octona (157), Achatina fulica (45) and Bradybaena similaris (23). Larvae obtained were submitted to polymerase chain reaction and restriction fragment length polymorphism diagnosis. Their genetic profile were corresponded to A. cantonensis. Rattus norvegicus experimentally infected with third-stage larvae, developed menigoencephalitis, and parasites became sexually mature in the lungs. Additionally, larvae obtained from A. fulica snails, from São Vicente, state of São Paulo, also showed genetic profiles of this nematode. This is the first record of Brazilian molluscs infected with this nematode species.