At least a few other, fancier varieties have been created. Due to their size and desire to school, they need large tanks. A half dozen could live in a 50 gallon tank without many other fish. They are very shy and tend to hide if they are not in a large enough school in a large tanks with lots of plants. They look like two small hairs on either side of underneath of their mouths.
Some people say the fish have whiskers.
When swimming quickly as danios do, the barbels are pressed against their bodies and difficult to see. Danios that are resting or making turns have easier to view barbels. On examining my fish, I noted no difference in the appearance or length of the barbels in males versus females. I will be referring to zebra, blue, leopard, and gold or albino danios all as danios. F. A temperature of about 72 degrees F is perfect.