Coldwater fish

[1] Although these fish are capable of surviving in unheated aquaria, their temperature preferences may vary.

Warm-water fish, such as largemouth bass, sunfish and bullhead catfish, are species that tend to dwell in relatively warm tropical and temperate waters similar to the room temperatures that humans easily find comfortable.

Cold-water species, such as salmonids (e.g. salmon, trout, char, graylings, freshwater whitefishes, etc.)

and gadiforms (cods, hakes, pollock, haddock, burbot and rocklings, etc.

Because these designations are informal, different fisheries management authorities may recognize different boundaries in temperature preference between the categories.