Interactions for food and space between sympatric populations of underyearling coho salmon and coastal cutthroat trout in a stream simulator during summer / by G.J. Glova and J.C. Mason. : Fs97-4/1428E-PDF

Interactions for food and space between sympatric populations of underyearling coho salmon and coastal cutthroat trout were investigated in a stream simulator during summer. In sympatry, partitioning of space was rapid and similar to that in nature, in that coho numerically dominated pools and trout dominated riffles. In allopatry, their microhabitat use was similar, in that 60-75% of either species occupied pools. Factorial analyses of variance indicated that size of fish, simulated food supply and water velocity were ranked (high to low) as affecting microdistribution. Coho and cutthroat trout fry communicated using an array of similar body postures and movements, with chases, nips and lateral displays comprising more than 80% of their total aggressive activity. Non-contact behaviors were more frequently used by coho; nipping was more frequently used by trout. Both salmonids were most aggressive when food was present. Species levels of aggressiveness were similar in allopatry, but differed between habitat types in sympatry, coho being more inclined to defend pools and trout riffles. Stream management strategy should take into account the importance of maintaining habitat diversification in streams supporting sympatric populations of coho salmon and cutthroat trout.

Lien permanent pour cette publication :
publications.gc.ca/pub?id=9.925348&sl=1

• Format MARC XML
• Format MARC HTML

Demander des formats alternatifs