Breeding male ninespine sticklebacks, Pungilius pungitius, are highly aggressive toward juvenile brook charr. Salvelinus fontinalis, in the Matamek River, Québec. Field observations revealed that such aggression was always initiated by the sticklebacks and only if the charr approached their nests or free‐swimming fry. There was considerable overlap in diet in August, but not in June and July, suggesting competition for food is possible under some circumstances. In laboratory stream tanks, we compared frequency of intraspecific and interspecific aggression of single and mixed species groups over a range of densities. There was no simple relationship between aggression and density for either species, although significant differences in aggression occurred among fish in some of the different density conditions.
|Original language||English (US)|
|Number of pages||8|
|Journal||Journal of Fish Biology|
|State||Published - Feb 1986|
ASJC Scopus subject areas
- Ecology, Evolution, Behavior and Systematics
- Aquatic Science