Diel feeding, daily food consumption and the predatory impact of whitemouth croaker (Micropogonias furnieri) in an estuarine environment |
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| Authors: | Gisela Mandali de Figueiredo & João Paes Vieira |
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| Institution: | Laboratório de Ciências Marinhas, Universidade Sul de Santa Catarina, Av. Colombo Sales 84, Laguna, SC, 88790-000 Brazil; Laboratório de Ictiologia, Departamento de Oceanografia, Fundação Universidade do Rio Grande, Rio Grande, RS, 96201-900 Brazil |
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| Abstract: | Diel feeding pattern and food consumption of whitemouth croaker (Micropogonias furnieri) were examined and related to seasonal variations in an estuarine environment. To determine diel feeding pattern whitemouth croaker were collected from the Patos Lagoon Estuary over 24 h (～3‐h intervals) and their stomach contents were examined. Food consumption of whitemouth croaker was determined from evacuation rates estimated experimentally and in the field. The results suggested that whitemouth croaker in the Patos Lagoon estuary feed all day long. However, whitemouth croaker showed higher feeding intensity and food consumption during daylight hours when the water transparency increased than in others when water transparency was low. Thus, whitemouth croaker seemed to intensify their feeding when they could see their prey. Daily food consumption was between 0.9 and 5.3% of body wet weight (these being the lowest and highest consumption rates during the winter and summer, respectively). The maximum predation impact of whitemouth croaker on their preferential prey, the tanaid Kalliapseudes schubartii, was 27indiv·m?2·day?1. The results suggested that the changes in water transparency seem to affect the diel feeding pattern and food consumption of whitemouth croaker. This could have important consequences for fish growth. |
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| Keywords: | Diel feeding diet Estuary food consumption whitemouth croaker |
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