The term coldwater fish can have different meanings in different contexts. In the context of fishkeeping, it refers to ornamental fish species that tolerate the temperatures of a typical indoor aquarium well and do not require a heater to remain active, as opposed to tropical fish, which need a heater to survive in the room temperatures of temperate climates; In the context of ecology and fishing, it refers to fish species that prefer to inhabit waterbodies or depth zones with much lower temperatures than the average temperate water. Salmonids (e.g. salmon, trout, char and graylings) are a classic example of such types of fish.
Fishkeeping Most or all ornamental fish species are able to tolerate temperatures as low as or lower than room temperature, with most stenothermic tropical species having critical thermal minimums of around 10-12 °C. Although these fish are capable of surviving in unheated aquaria, their temperature preferences may vary. For example, koi, goldfish, and pond loaches are commonly considered to be cold-water fish because of their ability to survive at very low temperatures, but their temperature preferences and/or physiological optimal temperatures are , , and , respectively. Because many of the ornamental fish considered to be “coldwater fish” are more accurately eurythermal fish and many prefer temperatures similar to, or even warmer than those preferred by certain tropical fish, the term “coldwater fish” in the aquarium context often misleads pet owners into keeping fish below their preferred temperature.
Freshwater aquarium fish
Southern redbelly dace Lepomis Shubunkin Comet goldfish Common goldfish Fancy goldfish Black telescope Fantail goldfish Oranda Ryukin Weather loach White Cloud Mountain minnow Celestial Pearl Danio Buenos Aires tetra Gold barb Rosy barb Odessa barb Fathead minnow Banded corydoras Chinese high fin banded shark Three-spined stickleback Ticto barb Pygmy sunfish Enneacanthus Texas cichlid Paradise fish Green barb Zebra danio Bengal danio Leopard danio Danio tinwini Bulldog pleco Rhinogobius Desert goby Highland swordtail (Xiphophorus malinche) Japanese ricefish Zacco Black lined loach (Yasuhikotakia nigrolineata) Red shiner (Cyprinella lutrensis) Spotted gar Longnose gar Rosy red minnow Hillstream loach Spined loach Stone loach Common minnow Vietnamese cardinal minnow GM glowing medaka Gobio Amur bitterling Rosy bitterling Light's bitterling Deep bodied bitterling Rainbow shiner (Notropsis chromosus) Black shark (not to be confused with the tropical red tailed black shark) Golden cobra snakehead Dwarf snakehead Rainbow snakehead Spotted snakehead (Channa punctata) Pearl danio Northern snakehead Chinese algae eater Variable platyfish
Note: The above contains a mix of true coldwater fish and sub-tropical fish that can survive and thrive at room temperature which ranges from and to .
Freshwater pond fish
Three-spined stickleback Nine-spined stickleback Common goldfish Comet goldfish Shubunkin Sterlet Koi Golden orfe Blue orfe Bitterling Gobio Grass carp Albino grass carp Fathead minnow Rosy red minnow Mirror carp Common carp Golden rudd Green tench Golden tench Channel catfish Golden rainbow trout Roach Bluegill Pumpkinseed Weather loach Stone loach Spined loach Common minnow
Saltwater aquarium fish
Garibaldi Catalina goby Zebra Catalina goby (Lythrypnus zebra) Ornate boxfish Shaw's boxfish White bar boxfish Truncate coralfish Blue devil Pot bellied seahorses
Wild fisheries The term "coldwater" is also used to refer to wild fish species that prefer bodies of water that are colder than most temperate waters. In recreational fishing, anglers may loosely break down fish into categories of warm-water fish, cool-water fish, and cold-water fish. 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. Cool-water species, such as smallmouth bass and walleye, can tolerate a wide range of temperatures, but tend to be most abundant in cooler rivers or deeper parts of ponds and lakes, where the temperature is slightly lower than room temperatures. 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.), however become stressed at warm temperatures and are most active in colder temperatures around which resemble a more subarctic or alpine condition. Because these designations are informal, different fisheries management authorities may recognize different boundaries in temperature preference between the categories.
See also List of freshwater aquarium fish species
References
Marine Aquarium Fish - http://www.oregonreef.com/sub_coldwater.htm
Freshwater Aquarium Fish - Practical Fishkeeping Magazine
Freshwater Pond Fish - An Essential Guide to Choosing Your Pond Fish and Aquatic Plants by Graham Quick and also http://www.pondexpert.co.uk/ChoosingTheRightFishForYourPond.html
External links About.com