Alimentação e fator de condição de Hemigrammus em igarapé da Reserva de Desenvolvimento Sustentável do Tupé, Amazonas

Abstract

The purpose of this work was to evaluate the feeding and condition factor of Hemigrammus levis and Hemigrammus coeruleus in a stream in the Reserve de Sustainable Development of Tupé. Taking into account ecological aspects such as food composition, relationship between availability of use of prey, fractional trophic level, trophic niche breadth, overlap food and condition factor. The collections were located in a stream (central), in the RDS of Tupé, with the aid of sieves and rapichés during the flood between December 2019 and January 2020. After the capture, the specimens were transported to the Ichthyology Laboratory – LABIC/UFAM. Food Importance index (IAi%), electivity, trophic niche breadth (BA), dietary overlap were analyzed as well the fractional trophic level and condition. Both species showed greater consumption of insects (H. levis: IA>80% and H. coeruleus (IA<50%). Both species presented food preference for the same items. Despite the large supply of food items, there was no partition of items, indicating low overlap to feed. The trophic niche breadth indicated that H. levis had a diet specializing in insects and H. coeruleus a more generalized diet. The value for the relative condition factor kn was around 1, indicating that the species were in an excellent state of well-being. H. levis has been categorized as an omnivore with a tendency towards insectivory, while H. coeruleus was categorized as omnivorous with a tendency to herbivory.