Freshwater fish are a popular option since it can be easier for beginners to set up a freshwater environment. ... Unlike fish that lay eggs, they give birth to live babies.

Fish experts believe the giant stingray, such as this one in Cambodia's Mekong River, is the largest freshwater species on Earth. This specimen measured more than 13 feet (4 meters) long.

These are the prettiest freshwater fish, from vibrant brook trout and pumpkinseed sunfish to majestic lake sturgeon. ... They can live for more than100 years and weigh more than 200 pounds.

Betta, or Siamese fighting, fish are among "the most popular freshwater aquarium fish in the world," PetMD reports. Native to southeast Asia, this species is known for its range of vibrant hues ...