Prochilodus lineatus (Valenciennes, 1837) is one of 270 fish species in the Rio Paraná system yet it comprises > 50% of the fish biomass and is the only fish species in the system known to feed entirely on flocculent benthic biofilm. We studied the feeding behavior and diet of P. lineatus, and the composition of benthic biofilm in river channels, the moving littoral, and in isolated floodplain lakes at different stages of the Rio Paraná hydrological cycle. Prochilodus lineatus selectively ingests hydrolysis-labile-organic-matter rich in amino acids while selectively rejecting mineral matter and refractory organic matter. Assessed in terms of g AA assimilated · kJ⁻¹ energy assimilated, the quality of food ingested by P. lineatus ranges from a maintenance level of 5 to 12 mg AA · kJ⁻¹, a level expected to produce near maximum growth. The level of amino acids in benthic biofilm is highest in shallow waters during the advancing flood (the moving littoral), and P. lineatus have been observed to feed in littoral areas so shallow that their dorsal fins and backs are exposed. Feeding intensity increases with river height as the moving littoral expands. Feeding site selection, selective ingestion, and conditional feeding intensity each increase amino acid assimilation and together constitute a trophic strategy that allows P. lineatus to dominate the fish community of the Rio Paraná.

Prochilodus lineatus (Valenciennes, 1837) 是 Rio Paraná 系统中 270 种鱼类之一，但它占鱼类生物量的 50% 以上，是该系统中已知的唯一完全以絮状底栖生物膜为食的鱼类。我们研究了P. lineatus的摄食行为和饮食，以及在 Rio Paraná 水文循环的不同阶段，河道、移动的沿岸和孤立的洪泛平原湖泊中底栖生物膜的组成。Prochilodus lineatus选择性地摄取富含氨基酸的水解不稳定有机物，同时选择性地排斥矿物质和难降解的有机物。根据 g AA 同化 · kJ ^{-1能量同化评估，} P. lineatus摄入的食物质量范围从 5 到 12 mg AA · kJ ^-1的维持水平，该水平预计会产生接近最大的生长。在前进的洪水（移动的沿海）中，底栖生物膜中的氨基酸水平在浅水区最高，并且观察到P. lineatus在沿海地区觅食，以至于它们的背鳍和背部暴露在外。随着沿岸移动的扩大，摄食强度随着河流高度的增加而增加。喂养地点选择、选择性摄入和有条件的喂养强度都增加了氨基酸同化，共同构成了一种营养策略，使P. lineatus能够在 Rio Paraná 的鱼类群落中占主导地位。