Koi have six types of color cells in their skin ... Koi are actually a type of carp, and today they're some of the most expensive pet fish in the world. But why? Koi were originally raised ...

Both new and experienced pet fish owners often fret about finding a healthy species to introduce to their aquarium. But, how do you even measure the health of one species against the others?

The Invasive Species Action Network also has fish rehoming resources and urges potential pet owners to consider local and state regulations when choosing a pet fish as well as the vegetation ...

This species, with its many varieties, is the most common betta fish found in aquariums and pet stores, but it has more than 70 relatives, including the endangered Betta miniopinna and Betta ...

Aquarium enthusiasts are often on the lookout for colorful and exciting species that they can raise in their personal tanks. Rainbowfish are a broad category of fish that meet these requirements.

Near a village in northeastern India, a “dwarf”-like creature with a “large” mouth swam through the river — or tried to, at least. But something pulled it out of the water, moved it around and dropped ...

football-sized invaders that compete with native species for food and habitat,' the website reads. As bottom feeders, the traditional pet fish make it harder for native aquatic animals and plants ...

Your pet store goldfish after two years ... disrupting aquatic ecosystems and making it harder for native fish and plants to survive. Goldfish also breed quickly, and since they don't have natural ...