For what it is worth, the Curimã is a fairly large fish. I know it by no other name. I was once told that they run about 30 pounds. The fisherman's hope is to catch one because it will bring more money than some of the others that he might catch. When I was taught the song, I was given the impression that "lambaio" refers to a somewhat smaller fish. The fisherman prefers the former but would be happy to catch either. I'm not too sure about this last bit and would welcome more knowledgeable input.