%0 Journal Article
%T Resource use by the facultative lepidophage Roeboides affinis (G邦nther, 1868): a comparison of size classes, seasons and environment types related to impoundment
%A Miriam P. Albrecht
%A Vanessa C. S. Reis
%A 谷rica P. Caramaschi
%J Neotropical Ichthyology
%D 2013
%I Sociedade Brasileira de Ictiologia
%X We report the consumption of scales and other food resources by the facultative lepidophage Roeboides affinis in the upper Tocantins River where it was impounded by the Serra da Mesa Hydroelectric Dam. We compared the diet among size classes, between dry and wet seasons, and between sites with distinct water flow characteristics (lotic vs. lentic) related to the distance from the dam and phase of reservoir development. As transparency and fish abundance increased after impoundment, we expected a higher consumption of scales in lentic sites. Likewise, habitat contraction, higher transparency and decrease in terrestrial resources availability, would promote a higher consumption of scales. Scales were consumed by 92% of individuals and represented 26% of the total volume of resources ingested by R. affinis. Diet composition varied significantly among size classes, with larger individuals consuming more scales and larger items, especially odonatans and ephemeropterans. Scale consumption was not significantly different between dry and wet seasons. Roeboides affinis incorporated some food items into the diet as a response to the impoundment, like other species. Scale consumption was higher in lotic sites, refuting our initial hypothesis, what suggests that the lepidophagous habit is related the rheophilic nature of R. affinis. Caracterizamos o consumo de escamas e outros recursos alimentares por Roeboides affinis, um lepid車fago facultativo, no alto rio Tocantins, na regi o represada pela Usina Hidrel谷trica de Serra da Mesa. A dieta foi avaliada em rela  o a classes de tamanho, esta  es chuvosa e seca, e entre locais com caracter赤sticas distintas de fluxo d'芍gua (l車tico vs. l那ntico) relacionadas com a distancia da barragem e fase de desenvolvimento do reservat車rio. Com o aumento da abundancia de peixes e da transpar那ncia da 芍gua ap車s o represamento, esperamos um maior consumo de escamas nos locais l那nticos. Da mesma forma, na 谷poca seca, o habitat menor e mais transparente, al谷m da redu  o da disponibilidade de itens terrestres, levaria a um maior consumo de escamas. Escamas foram consumidas por 92% dos indiv赤duos e representaram 26% do volume total de itens ingeridos por R. affinis. A composi  o da dieta variou significativamente entre classes de tamanho, com indiv赤duos maiores consumindo mais escamas e itens de maior porte, especialmente odonatas e efemer車pteros. N o houve diferen a no consumo de escamas entre as esta  es seca e chuvosa. Roeboides affinis incorporou itens 角 sua dieta como resposta ao represamento, a exemplo de outras esp谷cies na bacia do alt
%K Diet
%K Hydrological regime
%K Impoundment
%K Scale-eating
%K Tocantins-Araguaya basin
%U http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1679-62252013005000713