Comparação da eficiência de dois métodos de coleta de peixes em igarapés de terra firme da Amazônia Central

Abstract

Studies of spatial distribution, feeding habits and community structure of small size fish species in forest streams usually employ some specific collecting methods related to the size and structural characteristics of these aquatic environments. This study aimed to compare the efficiency of two fishing methods, one active (hand net and sieve) and one passive (minnow traps). Collecting with hand nets yielded a higher number of fish species and individuals. There was apparently a high escape rate in the minnow traps, as well as some losses of collected specimens by predation inside the traps by the carnivorous Erythrinus erythrinus, that may have resulted in the lesser efficiency of the passive fishing method. The low similarity values observed in the samples obtained with the two fishing methods at each stream indicate that is necessary to combine different sampling procedures to ensure its effectiveness. Nevertheless, the lower habitat disturbance resulting with the use of minnow traps may be especially useful for studies developed in protected areas, with a proper adjustment of the sampling effort.