Which one of these is not an Oto?..

[nonemvijar]

Hello catfish experts..I bought a couple of Otocinclus catfish yesterday from my lfs. Or atleast thats what i was told they are.

They both look quite different and also differ quite a bit in temperament. The grey one looks more like a "regular" Oto, is much more calm and remains mostly at the bottom while the darker one is very very active, swims around really fast and also frequently goes to the surface of the water (to take a breath??)..

Not sure if this is just an example of 2 Otos that are different from each other or if these are 2 different types of catfish. Any insight is greatly appreciated!..

Tank Details : 5 Gallon Planted (wisteria, anubias nana and parrot feathers) & maintained at 78-80 F.
Occupants : 1 Male Betta and 2 Catfish

Thanks!!..RM.

[Valb68]

They both look like hungry otos to me. Maybe drop them some Zucchini or spinach?

[Amneris3]

Yep, would say both otos, not sure the species. Coloration can vary and also change if the fish is stressed. In my experience, they tend to be delicate and can sometimes have problems acclimating.

[Jumpmaster]

They are both otos. As mentioned, some blanched courgete will be welcomed