Siamese Algae Eater or SAE:
The true SAE has a jagged black horizontal stripe that goes all the way to the tip of the tail. All of the SAE's fins are clear. The black and white and their contrast are more intense than with the other algae eaters below.
False Siamese Algae Eater or false SAE:
The false SAE if usually found in shipments of true SAE (or the other way around). Unlike the SAE, the black stripe ends at the beginning of the tail. Often, if one goes to buy SAE's in a US aquarium store, they may in fact be all or mostly false SAE's. False SAE's may have some red around the mouth and a yellow tint to the fins. My false SAE had some nice gold and red on the dorsal fin. Mine was sold as a flying fox.
Flying Fox:
Just like the true SAE, the flying fox has a black horizontal stripe that goes all the way to the tip of the tail. Unlike the SAE, the edges of the stripe are smooth and not zagged. The flying fox may have some rainbow-like coloring on the fins. It is more pretty than the other fish mentioned on this page. The black horizontal stripe extends to the end of the tail like the SAE but it is much stronger and broader.