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Aquarium Fish

The first fish were kept as pets in the Roman Empire in marble tanks. In 1369, the Chinese started making porcelain tanks to keep goldfish. If you have a pet fish, guess what? You can start calling yourself an aquarist, the official word for someone who keeps an aquarium. Today there are over 60 million aquarists worldwide.


Angelfish are freshwater fish. They're very flat with black and white stripes and very tall vertical fins. They are very intelligent fish and can even recognize their owners. They are prized for their beauty and, like the wolf eels that you can find in the Deep Sea Stamp collection, they mate for life.


Archerfish get their name from a peculiar talent. When they're in the wild, in waters off of Asia and India, they can shoot water from their specialized mouths and hit targets up to six inches above the water. They've got excellent eyesight and good aim. They can even leap out of the water to catch insects in their extra-large mouths.


These small, colorful fish originated in Thailand and are one of the most popular aquarium fish. Bettas are also called Siamese Fighting Fish, for good reason. They often fight to the death. Two males, a male and a female and two females should never be in the same tank. The best solution is three female Bettas in a tank.

Blood Parrot

Blood Parrots are bright red fish created in Taiwan in 1996. They are a very controversial fish because they have tons of problems and deformities since they are a product on inbreeding. For example, they cannot close their mouths. A lot of pet stores and breeders boycott Blood Parrots because they don't have a very good quality of life.


The Discus is a flat, brightly colored fish. They live best with the angelfish and different species of Tetra. When they breed, Mom and Dad both care for the children and secrete a special protein in their mucus membrane for their offspring to eat. They are sickly fish that don't live that long, but they're very popular pets in Asian countries.

Electric Catfish

These fish are shocking, really! Electric catfish, while not very common as pets, were kept and depicted by ancient Egyptians in tomb murals. These long, whiskered catfish can generate an electric shock of up to 350 volts to stun and paralyze their prey. Fortunately, the shock isn't fatal to humans.


Goldfish are one of the most popular aquarium fish. They're members of the carp family and originated in Asia. There are many types of goldfish, and with proper care, most can live up to 20 years in good health. Are goldfish trouble? You decide. A group of goldfish is called a "troubling."


Guppies have rich jewel-tone colors and are a very popular freshwater aquarium addition. Guppies breed and deliver live babies instead of laying eggs. It takes a pregnant guppy three to four weeks to deliver babies, called fry. Unfortunately, guppies will often eat their own fry so aquarists must give the babies a safe place to live.


Hatchetfish have huge fins on their backs connected to very powerful muscles. They swim right below the surface of the water and can sometimes launch themselves right out of the water and "fly" to catch insects. Because of this, their aquariums should have a tight lid to keep them from ending up on the floor!


Oscars are good aquarium fish because they grow slowly. But they sure do grow! Adult Oscars can grow up to 18 inches long. They have a lot of different looks, from dark gray to white. They're predators, but many aquarists consider them very low key and friendly fish that coexist well with other aquarium residents.


Pencilfish get their name from their slender, long bodies. They're a freshwater fish that originates in South America. The pencilfish and its close relative, the splashing Tetra, are popular aquarium fish. While some fish have teeth on both jaws, pencilfish only have an upper row of chompers.


Keeping a piranha is not for the faint-hearted. These fish are originally from the Amazon basin and eat everything in their path. Their teeth have been used as tools by fishermen for thousands of years. Piranhas have to be kept in even-numbered groups, or they'll gang up on each other. They're illegal in some places like Washington State.


Swordtails have sharp tails that look like a sword sticking behind the fish. They are small and, like guppies, they give birth to live babies. They have very straightforward, easily understood genes and are often used by scientists for experiments and research. As a result, there are many interesting hybrid species of the swordtail fish.


Tetra is a blanket name for many different kinds of fish. In general, they're small fish that live well in aquariums. Penguin Tetras, Ruby Tetras and Jellybean Tetras are just some of the species in this big group. The most interesting is the X-ray Tetra because its body is almost completely see-through.