Chinese Algae Eater

Thinking they are?? How can I tell? I know my golden is a male because it has the "Horns", but I can't tell what my other one is, but I know lately they have been inseperable, following each other around and stuff. Any info would be appreciated. Thanks.

The little bit I know of them is that they can get like 6" and as they age can get aggressive. They can latch on to sides of fish and kill them. Those are reasons I've always shyed away from them and opted for other , more efficient algae eaters.