RESUMO
Animal welfare regards the quality of life and the environment in which animals live or are exposed. Hence the importance of studies assessing the environmental influence on the biology and behavior of fishes from the Colossoma macropomum species, considering their higher potential for fish-farming and as a test organism in scientific research. This study aimed to assess, in a controlled environment, the behavioral changes expressed by juveniles from the Colossoma macropomum species exposed to different ambient colors or social situations. The results did not show an influence from the different ambient colors or social situations on fish distribution in the water column. The color pattern showed dark tones in black- and blue-colored environments, and light tones in white-colored environments or with the presence of a mirror. The time of locomotor activity/frequency did not change in any of the treatments of exposure to environments with colors and a mirror. Moreover, the fishes remained with folded fins and a straight posture, maintaining a pattern of rhythmic operculum beating in a normal frequency range described for the species. This suggests that animal welfare did not change in any of the situations tested and that there was a pattern of adaptive response to the type of environment.
Assuntos
Comportamento Animal , Bem-Estar do Animal , PeixesRESUMO
The aim of this paper was to report the occurrence of Austrodiplostomum spp. in the eyes and brain of Acaronia nassa, Caquetaia spectabilis, Satanoperca acuticeps, Curimatella sp. and Crenicichla marmorata in a lake of the Amazon River system in the state of Pará (Brazil). Of 49 fish examined, 10.2% were parasitized by Austrodiplostomum spp. metacercariae, and A. nassa was the host with higher number of metacercariae. In five examined fish species, a total of 51 metacercariae were collected, with 45 found in the eyes and 6 in the cranial vault. In the eyes, the metacercariae were free and active in the vitreous humor, but no opacification was observed. In the brain, the metacercariae were also free and active, and located mainly below the encephalon, on the cranial floor, at the height of the ophthalmic lobes and near the optic nerve. In laboratory observations, however, the infected fish did not exhibit any behavioral disorders, and this may be related to the low level of parasitism. This was the first report of this digenean for C. spectabilis, S. acuticeps, Curimatella sp., C. marmorata and A. nassa.(AU)
O objetivo deste trabalho foi relatar a ocorrência de Austrodiplostomum spp. nos olhos e cérebros de Acaronia nassa, Caquetaia spectabilis, Satanoperca acuticeps, Curimatella sp. e Crenicichla marmorata em um lago do rio Amazonas no estado do Pará (Brasil). Dos 49 peixes examinados, 10,2% foram parasitados por metacercárias de Austrodiplostomum spp., A. nassa sendo o hospedeiro com maior número de metacercárias. Em cinco espécies de peixes examinadas, foram coletadas 51 metacercárias, sendo 45 encontradas nos olhos e 6 na caixa craniana. Nos olhos, as metacercárias estavam livres e ativas no humor vítreo, mas nenhuma opacificação foi observada. No cérebro, as metacercárias também eram livres e ativas, localizadas principalmente abaixo do encéfalo, no assoalho do crânio, na altura dos lobos oftálmicos e próximo ao nervo óptico. Em observações laboratoriais, no entanto, o peixe infectado não apresentou distúrbios comportamentais, o que pode estar relacionado ao baixo nível de parasitismo. Este foi o primeiro relato de Austrodiplostomum spp. em C. spectabilis, S. acuticeps, Curimatella sp., C. marmorata e A. nassa.(AU)