Inhabits muddy pools of headwaters, creeks, small rivers and ponds (Ref. 5723). Also found in lakes (Ref. 10294). Tolerates unsuitable conditions (e.g., turbid, hot, poorly oxygenated, intermittent streams) for most fishes (Ref. 5723). Feeds on detritus and algae (Ref. 10294). Spawns in still-water habitats along shores (Ref. 59043). Introductions consequently caused the spread of the enteric red-mouth disease throughout northern Europe which infected wild and cultured trouts and eels (Ref. 1739). Maintained a relatively high metabolic rate and level of activity under hypoxic conditions (Ref. 77050). Individuals that survived the hypoxic conditions during winter had rapid growth rates after ice-off (Ref. 77048).