The importance of substrate size and interstitial space in the microhabitat selection by the stream-dwelling catfish Hatcheria macraei (Actinopterygii, Trichomycteridae)

BARRIGA, J:P.; ESPINÓS, N. A.; CHIARELLO SOSA, J. M; BATTINI, M. A.

HYDROBIOLOGIA

SPRINGER

Lugar: Dordrecht; Año: 2013 vol. 705 p. 191 - 206

0018-8158

The aim of this study was to test whether diurnal microhabitat use by Hatcheria macraei depends upon specific environmental parameters and/or the abundance of the other fishes. We carried out a one-year field study in a low-order river of northern Patagonia, Pichileufu River, and also experimental trials to determine substrate preferences. Fishes were captured during daylight and physicochemical environmental variables were recorded. Headwater zones were dominated by rainbow trout (Oncorhynchus mykiss) and brown trout (Salmo trutta) while native fishes, H. macraei and the creole perch (Percichthys trucha), were more abundant downstream. Hatcheria macraei inhabited mostly shallow microhabitats with fast water velocity and a significant interstitial space among substrate, independently of the abundance of other fishes. Experimental trials pointed out that H. macraei preferred mostly coarser substrates (>6 cm), avoiding fine ones. This work highlights the importance of erotional zones with high water velocity, large substrates and suitable interstitial space in the microhabitat selection of H. macraei. The knowledge of microhabitat use by native fish populations is critical for management and conservation strategies and should be taken into account prior to any river modification