Fishkeeping in the context of "Garden pond"

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 whom 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.

An aquarium (pl.: aquariums or aquaria) is a vivarium of any size having at least one transparent side in which aquatic plants or animals are kept and displayed. Fishkeepers use aquaria to keep fish, invertebrates, amphibians, aquatic reptiles, such as turtles, and aquatic plants. The term aquarium, coined by English naturalist Philip Henry Gosse, combines the Latin root aqua, meaning 'water', with the suffix -arium, meaning 'a place for relating to'.

The aquarium principle was fully developed in 1850 by the chemist Robert Warington, who explained that plants added to water in a container would give off enough oxygen to support animals, so long as the numbers of animals did not grow too large. The aquarium craze was launched in early Victorian England by Gosse, who created and stocked the first public aquarium at the London Zoo in 1853, and published the first manual, The Aquarium: An Unveiling of the Wonders of the Deep Sea in 1854. Small aquariums are kept in the home by hobbyists. There are large public aquariums in many cities. Public aquariums keep fish and other aquatic animals in large tanks. A large aquarium may have otters, dolphins, sharks, penguins, seals, and whales. Many aquarium tanks also have plants.

Cichlids (/ˈsɪklɪdz/)are a large, diverse, and widespread family of percomorph fish in the family Cichlidae, order Cichliformes. At least 1,760 species have been scientifically described, making it one of the largest vertebrate families, with only the Cyprinidae being more speciose. New species are discovered annually, and many species remain undescribed. The actual number of species is therefore unknown, with estimates varying between 2,000 and 3,000. They are native to the Neotropics, Africa (including Madagascar), the Middle East, and the Indian subcontinent, although some species have been introduced worldwide.

Many cichlids, particularly tilapia, are important food fishes, while others, such as the Cichla species, are valued game fish. The family also includes many popular freshwater aquarium fish kept by hobbyists, including the angelfish, oscars, and discus. Cichlids have the largest number of endangered species among vertebrate families, most in the haplochromine group. Cichlids are particularly well known for having evolved rapidly into many closely related but morphologically diverse species within large lakes, particularly Lakes Tanganyika, Victoria, Malawi, and Edward. Their diversity in the African Great Lakes is important for the study of speciation in evolution. Many cichlids introduced into waters outside of their natural range have become nuisances.

Lists of aquarium life include lists of fish, amphibians, invertebrates and plants in freshwater, brackish and marine aquariums.In fishkeeping, suitable species of aquarium fish, plants and other organisms vary with the size, water chemistry and temperature of the aquarium.

An aquarium heater is a device used in the fishkeeping hobby to warm the temperature of water in aquariums. Most tropical freshwater and marine aquariums are maintained at temperatures that range from 22 to 30 °C (72 to 86 °F). The types include glass immersion heaters and undergravel heating. There are also heating mats that may be placed under the aquarium.

Tropical fish are fish found in aquatic tropical environments around the world. Fishkeepers often keep tropical fish in freshwater and saltwater aquariums. The term "tropical fish" is not a taxonomic group, but rather is a general term for fish found in such environments, particularly those kept in aquariums.

Aquarium fish feed is plant or animal material intended for consumption by pet fish kept in aquariums or ponds. Fish foods normally contain macronutrients, trace elements and vitamins necessary to keep captive fish in good health. Approximately 80% of fishkeeping hobbyists feed their fish exclusively prepared foods that most commonly are produced in flake, pellet or tablet form. Some fish foods also contain additives such as sex hormones or beta carotene to artificially enhance the color of ornamental fish.

Algae eater or algivore is a common name for any bottom-dwelling or filter-feeding aquatic animal species that specialize in feeding on algae and phytoplanktons. Algae eaters are important for the fishkeeping hobby and many are commonly kept by aquarium hobbyists to improve water quality. They are also important primary consumers that relay the biomass and energy from photosynthetic autotrophes up into the food web, as well as protecting the aquatic ecosystem against algae blooms.