Evidence of microhabitat overlap between juvenile of introduced salmon Oncorhynchus tshawytscha and the native fish Trichomycterus areolatus in the Allipen River, Chile

Resumen:
Introduced juvenile Chinook salmon (Oncorhynchus tshawytscha) have been found co-occurring with native fishes in the Allipen River, Chile. Due to this co-occurence, the microhabitat use, microhabitat preferences, and overlap between juvenile Chinook salmon and the native catfish, Trichomycterus areolatus, were examined during the summer and fall of 2007-2008. Microhabitat preferences and overlap between juvenile Chinook salmon and the native catfish were determined using the Instream Flow Incremental Methodology and the Pianka's index. Juvenile Chinook salmon and the native catfish microhabitat preferences varied seasonally showing a high degree of similarity and overlap between the species (higher than 80%). The results suggest the risk of negative interactions and interactive segregation over habitat processes between juvenile Chinook salmon and native catfish. As a consequence, the Chinook salmon invasion may threaten the stability of native catfish populations at Allipen River.

Recursos relacionados