Though less colorful than some of its cousins, the Slender Rasbora exhibits a prominent blue-black line running along the length of its body. This feature has earned the Slender Rasbora a variety of nicknames including Black Line and Gold Line Rasbora. Native to Southeast Asia, the Slender Rasbora can be found in a variety of waterways including streams, ponds, ditches and flooded fields. In the wild, these fish can be found in large schools. In the home aquarium, Slender Rasboras are best kept in groups of five or more.