Interactions of slimy sculpin (Cottus cognatus) with native and nonnative trout: consequences for growth

• Published in: Canadian journal of fisheries and aquatic sciences Vol. 63; no. 7; pp. 1526 - 1535
• Main Authors: Zimmerman, Julie KH, Vondracek, Bruce
• Format: Journal Article
• Language: English
• Published: Ottawa, Canada NRC Research Press 01.07.2006; National Research Council of Canada; Canadian Science Publishing NRC Research Press
• Subjects: Agnatha. Pisces; Animal and plant ecology; Animal behavior; Animal, plant and microbial ecology; Animals; Autoecology; Biological and medical sciences; Cottus cognatus; Fish; Freshwater; Fundamental and applied biological sciences. Psychology; Growth; Native species; Nonnative species; Physical growth; Physiological aspects; Riffles; Salmo trutta; Salvelinus fontinalis; Sculpin; Studies; Trout; Vertebrata; Vertebrates: general zoology, morphology, phylogeny, systematics, cytogenetics, geographical distribution; United States; USA, Minnesota; USA, Minnesota, Valley Creek; Freshwater environment; Aquatic environment; Vertebrata; Introduced species; Salmo trutta; Growth; Trout; Pisces; Interaction; Interspecific competition; Native species; Interspecific relation
• ISSN: 0706-652X; 1205-7533
• DOI: 10.1139/f06-054

We examined growth of native slimy sculpin (Cottus cognatus), native brook trout (Salvelinus fontinalis), and nonnative brown trout (Salmo trutta) to investigate potential interactions of a native nongame fish with native and nonnative trout. Enclosures (1 m 2 ) were stocked with five treatments (juvenile brown trout with sculpin, juvenile brook trout with sculpin, and single species controls) at three densities. Treatments (with replication) were placed in riffles in Valley Creek, Minnesota, and growth rates were measured for six experiments. We examined the difference in growth of each species in combined species treatments compared with each species alone. We did not find evidence of inter actions between brook trout and sculpin, regardless of density or fish size. However, sculpin gained greater mass when alone than with brown trout when sculpin were >16 g. Likewise, brown trout grew more when alone than with sculpin when brown trout were >24 g. In contrast, brown trout ≤5 g grew more with sculpin compared with treatments alone. We suggest that native brook trout and sculpin coexist without evidence of competition, whereas nonnative brown trout may compete with sculpin.