Fish feeding: a proposal for analysis of the stomach content
Keywords:trophic ecology, dominance, weight, frequency of occurrence, feeding index (IAi), methods
AbstractThis study aimed to test a simplified protocol for feeding fish analysis. For this, the food items found in the gastric contents of six freshwater fish species (Astyanax paranae, Phalloceros caudimaculatus, Loricariichthys platymetopon, Moenkhausia intermedia, Schizodon intermedius, and Plagioscion squamosissimus) were quantified by weight (%) and dominance (%). Using the quantification by weight for each food item, the IAi (Feeding Index) was calculated and further compared with the dominance (D) using the Morisita-Horn similarity coefficient. The food items with higher values of IAi were also those with the largest dominance values. The general similarity between IAi and dominance (D) was high, varying of 87% (A. paranae) to 99% (P. caudimaculatus, L. platymetopon, S. intermedius, and P. squamosissimus), showing that dominance can replace composed indexes calculation. The graphic representation of weight and dominance against the frequency of occurrence showed that both are adequate to identify the most important food items, revealing that dominance may alternatively be used instead of prey items weighting, simplifying the data collection and analysis. When the objective of the trophic study is to identify the food items that stand out in quantitative terms or investigate specialization/generalization tendencies, we recommend the use of the dominance in combination to graphic methods.
How to Cite
Bennemann, S. T., Casatti, L., & Oliveira, D. C. de. (2006). Fish feeding: a proposal for analysis of the stomach content. Biota Neotropica, 6(2). Retrieved from //www.biotaneotropica.org.br/BN/article/view/192