Occurs in standing to slow-flowing water, mostly in vegetated ponds and lakes, backwaters and quiet pools of steams. Frequents brackish water (Ref. 5723). Observed to inhabit warm, still waters, typically seen shoaling at the edges of streams and lakes (Ref. 44894). Feeds on small terrestrial insects usually in the drift and amongst aquatic plants, actively selecting very small prey (Ref. 6154). Feeds also on mosquito larvae (Ref. 41168). Introduced worldwide. Introductions to Europe have seriously threatened many endemic species (Ref. 59043). It is now widely accepted that their effect has been minimal and even may have exacerbated the problem due to their voracious appetite for natural invertebrate predators of mosquito larvae (Ref. 44894).