Do benthivory and piscivory result in similar growth in walleye?
Abstract:Growth and condition of piscivorous and non-piscivorous walleye Sander vitreus classified on the basis of their stomach contents were compared to assess the consequences of their trophic flexibility. Piscivorous males showed a significantly higher growth trajectory than non-piscivorous ones, while there was no difference in the growth of females. No differences were found in the condition of piscivorous and non-piscivorous walleye for either sex. Trophic specialization of males, with some individuals foraging mainly on invertebrates and others including forage fishes in their diets, seems to be the most plausible explanation for the observed growth differences. The results also suggest that invertebrates are an important component in walleye diet throughout its ontogeny.
Document Type: Regular Paper
Affiliations: 1: Groupe de recherche sur les écosystèmes aquatiques, Université du Québec à Trois-Rivières, C.P. 500, Trois-Rivières (Quebec), G9A 5H7, Canada 2: Université des Sciences et Technologie de Lille 1, Cité Scientifique 59655, Villeneuve d’Ascq Cedex, Nord Pas-de-Calais, France
Publication date: 2006-11-01