What is a betta fish? Betta fish—also known as Siamese ... at the water’s surface to build what’s called a mucus bubble nest. He then puts on a display to attract a female, becoming brighter ...

It often takes a careful eye to identify the sex of a beta fish. Reviewed by Nick Saint-Erne Reviewed by Nick Saint-Erne Determining the gender of a betta fish ... bettas blow a bubble nest.