What actually is this fish?

[Tvsaint]

https://m.youtube.com/watch?v=mPsV72WTXds 

[Tvsaint]

1 minute ago, Tvsaint said:

https://m.youtube.com/watch?v=mPsV72WTXds 

So I thought I bought an otocinclus but he has gotten huge. He comes out in the middle behind the black skirt tetra. He’s a good 4 inches long but I thought they were only supposed to get like 2 inches max. He hides for months where I never see him but I finally got him on video after trimming my foliage 

[Lowells Fish Lab]

My guess is chinese algae eater. 

[Sarina]

Definitely not an oto, it looks like a Chinese algae eater to me. Unfortunately as adults they can be pretty aggressive and may go after your other fish. Keep a close eye. For future reference, otocinclus are a very light silver and CAEs tend to be a tan or brown color, even as juveniles.

[Colu]

Definitely a Chinese algae eater

Edited May 31, 2021 by Colu

[CorydorasEthan]

Definitely not an oto. I'm guessing (as said above) that it is either a chinese "algae eater", or some sort of Garra species, both of which might not be suitable for the tank size and fish selection that you already have. Adding on to what @Nirvanaquatics said about identification, otocinclus will have a pointed snout, and usually a dark line going from the tip of the snout to the base of the tail. Here's an Otocinclus species for reference.

Sucking loaches (the group that CAEs and Garra species are usually put into) will all have round snouts and will be much bigger as well.

I hope this helps, and good luck!