Introducing: Schooling Fishes
by Ruby Bayan
Characins, or Characiformes, are native to Africa and Central America. Most of them have teeth and prefer insects, but will hardly balk at other types of food. The most common aquarium specie is the tetra, although hatchetfishes, pencilfishes, as well as piranhas, belong to this group of active swimmers. Mostly shoaling fishes, Characins prefer clean, clear, running water – they like highly oxygenated habitats, being highly sensitive to poor water quality.
Cyprinids, or Cypriniformes, on the other hand, proliferate all over the world. They are toothless – they grind their food in their throats – and are omnivorous. Often referred to as “eating machines”, this highly active group of fishes feed on practically anything that fits their mouths. Schooling tropical Cyprinids include the favorite barbs, rasboras, and danios.
No self-proclaimed tropical fish hobbyist has not heard of or cared for a tetra. Commercially bred for the aquarist trade, tetras are sold all over the world, giving all the enthusiasts the opportunity to appreciate a splendid display of color and agility, as well as the challenge in keeping schooling fishes healthy and viable in a community setup.
The favorite aquarium tetras are the African Tetras (Congo Tetra and African Red-Eyed Tetra) and the South American Tetras (the Neon [see photo], Glowlight, Lemon, Cardinal, and Emperor Tetras).
All tetras prefer soft, slightly acidic, well-oxygenated tanks that are well planted. Their ideal water condition is usually achieved after the tank has stabilized for a few months, which is why experts recommend that tetras be introduced only to well-established aquariums. Tetras also enjoy swimming against a slight current; a good power pump will provide both mild current and surface movement for adequate oxygenation of the water.
True schooling fishes, tetras, which are mostly smallish, stand a better chance of survival if they are introduced into a community as a group of at least eight fishes. In small numbers, they will tend to hide among the plants or become attractive prey to bigger fishes.
Widely captive-bred in thousands of fish farms in Asia, Africa, Europe, and Florida, barbs have been a long-standing favorite of the tropical fish hobbyist. The more popular ones are the Tiger Barb, Cherry Barb, Green Tiger Barb, Filament Barb, and Checker Barb.
Extremely active, barbs, especially Tiger Barbs [see photo], have gained notoriety for terrorizing fellow community members and jumping out of the tank during a feeding frenzy. Kept in groups of eight to ten, however, barbs tend to behave, interacting with their own kind than with other fishes. Installing a good fitting aquarium cover is the only solution for hyperactive barbs.
Barbs are also true schooling fishes, feeling insecure and unhappy when alone. Swimming about as tightly formed schools, barbs prefer open spaces; a large tank without too much vegetation is the best habitat for them.
Just as popular as the tetras and barbs, danios also make good schooling fishes. These fishes originate from Asia and prefer fast-moving waters, as indicated by their slim bodies. The more popular varieties are the Zebra Danio [see photo], Giant Danio, and Pearl Danio.
Danios are relatively sensitive to water quality, susceptible to infections when water conditions are less than ideal or when temperatures fall outside of the 72-77 degrees F range. Generally peaceful, danios live comfortably in well-planted aquariums, but active as they are, a good-fitting tank cover will serve well against impulses to jump out.
Although danios will tolerate living alone or with one other danio, they are much happier when swimming around with eight to ten others of their own kind – in large tanks with plenty of space.
See also: Feeding and Breeding Schooling Fishes