Biology of a catfish, Trichomycterus sp (Pisces, Siluriformes), in a pristine stream in the Morro do Diabo State Park, southeastern Brazil
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Data
2003-08-01
Autores
Casatti, L.
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Editor
Swets Zeitlinger Publishers
Resumo
The distribution, activity, diet, and reproduction of an undescribed catfish species of the genus Trichomycterus (Trichomycteridae) were studied in the Morro do Diabo State Park, an important conservation area in the Rio Paranapanema basin, State of São Paulo, southeastern Brazil. Trichomycterus sp. is a rheophilic species occurring solely in the riffle areas of the streams and hunts mostly immature aquatic insects during the day by picking them from the substrate. The population has a balanced sex ratio, but females were uncommon in the smallest and largest size classes suggesting that females demonstrate a more accelerated growth pattern. Presence of mature individuals throughout the year represents an opportunistic reproductive tactic for fishes living in fast flowing waters, where the clutches could be shifted by the current, but the high incidence of mature individuals in the wet season may be related to optimal environmental conditions for juveniles during that period. Because of the restriction of Trichomycterus sp. to riffle environments, the conservation of this species depends on the maintenance of the original characteristics of these headwaters. That demands protecting the riparian vegetation and consequently the stream from excessive siltation resulting from runoff and erosion.
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Trichomycterus, catfish, conservation, Stream, feeding behavior, reproduction, diet, upper Rio Parana, Rio Paranapanema, Morro do Diabo State Park
Como citar
Studies on Neotropical Fauna and Environment. Lisse: Swets Zeitlinger Publishers, v. 38, n. 2, p. 105-110, 2003.