Cold Water Fishes

These fish can be salt or fresh water fish which needs colder water temperatures. Salmonidae, Goldfish, Trout, Weather loach, Phoxinus, Oncorhynchus, Salmon etc. Cold water fish are often unwilling to feed in more dense lower water near the bottom as this is more uncomfortable for them and too cold for their metabolism to be efficient. Coldwater fish thrive based on the natural conditions, whilst warm water fish to suffer from a lack of cover and the changes that occur in the water levels within the lake. The goldfish is the most common type of Coldwater species kept. It can live in an unheated aquarium. As they are of the carp family, goldfish produce a large amount of waste both in their feces and through their gills, releasing harmful chemicals into the water. This is because goldfish like other cyprinids, is without a stomach and only have an intestinal tract, and thus cannot digest an excess of proteins.