SAE vs others
The SAE, or Siamese Algae Eater is one of the few fish that will eat brush or beard algae, so often is counted among the arsenal of planted tank enthusiasts. They have been also been confused with almost every other fish imaginable, from Flying Foxes to Otocinclus catfish. Below is an adult true SAE.

Image of an adult True "SAE" (click
for enlargement) Courtesy of James
Forgan



Close up of SAE Mouth and above Courtesy of Mia Woodman
SAE's are most commonly confused with the Flying Fox, and the False Siamensis. What's worse is that often the SAE is called the Siamese Flying Fox. That does not mean a Flying Fox is the same as a SAE. Both the False siamensis, and Flying Fox have a gold to white stripe above the black lateral stripe the SAE is famous for. They are also both more spastic in a tank, and more likely to be sitting on the tank bottom or ornaments, while young SAE's are almost always moving, cleaning something, or schooling.


Image of juvie and adult False siamensis
Courtesy of Mia Woodman
Flying Fox image can be found at http://www.aquahobby.com/gallery/gfox.html
Strangely enough these fish are also confused with Chinese Algae Eaters, the most energetic fish you can buy. These fish are normally olive-green-yellow with a black lateral stripe, or broken lateral pattern. They are also very aggressive later in life, and not suited to a community tank. They also have a very pronounced sucker mouth. They are also available at just about every fish store.

Image provided by Eric
Naus

Image provided by Mia Woodman
And just to be thorough, some people will even mix them up with Otocinclus Catfish. I guess maybe you could confuse them when the SAE is tiny, but otherwise I don't get how. The Otocinclus has a sucker mouth, and gets 2 inches long tops. They will school, but are noticeably ventrally flattened rather than cylinder shaped.

Characteristics
Siamese Algae Eater (SAE)
- Two forward facing whiskers
- Black lateral stripe, going into tail, even as babies
- At larger size the scales on the body get black edged, on babies they are silver to almost white
- Clear fins with no white, black or yellow markings
- No pronounced suction mouth
- Hovers in place while cleaning leaves,
schools with like kind
False SAE
- No Visible whiskers
- Black lateral stripe, not continuing into tail
- Gold stripe above lateral black stripe
- Yellow-red fins, not tipped in white
- Sucker mouth when at rest
- Very spastic in nature, very rarely still or hovering, semi-aggressive to like kind
Flying Fox
- 2 forward whiskers, 2 others
- Black lateral stripe into tail
- Gold stripe above lateral black stripe
- Yellow-red fins, tipped in white over 2 inches
- No sucker mouth
- Semi-aggressive with everything, not a schooler when older
Chinese Algae Eater (CAE)
- No whiskers, sucker mouth
- Brown pattern or line on side, mimicking lateral stripe
- Yellow-olive green body color, also comes in bright yellow
- Fins marked by spots, stripes
- Sucker mouth
- Semi-aggressive, very energetic
Otocinclus Catfish
- No whiskers, sucker mouth
- Black stripe with dark top of body and bright white belly
- Fins kept folded unless swimming, have patterning
- 2 inch adult size
- peaceful as an adult and a schooler, and eats brown diatom algae, so not a bad critter
References:
- http://www.aquatic-gardeners.org/cyprinid.html -- Algae Eating Cyprinids, by Neil Frank and Lisa Sarakontu
- http://www.thekrib.com/Fish/siamensis.html -- FAQ on SAE
- http://www.wetwebmedia.com/fwsubwebindex/saes.htm -- Will the Real SAE Please Swim Forward?