Planted Tank Guru
Join Date: Jan 2010
Location: Contra Costa CA
I have Bristlenose, Otos, and a common Pleco in several tanks, and have kept quite a few other species (Rubberlip, Bulldog, Clown, Candystripe...), and none did that sort of damage.
Some species are more aggressive raspers than others, but before I would blame the Pleco, I would ask if the plants are as strong and healthy as they should be? Snails can also do this sort of damage, but they are weak raspers. If the plants are already compromised they can do damage to the weakened leaves.
Put a sheet of acrylic or glass in the tank as a divider. Keep the Pleco on one side. Does the damage get worse on that side, and not show up any more on the protected side? If so, then blame the Pleco.
How to solve the problem:
1) Feed the pleco often with cooked vegetables. Raw cucumber, lightly cooked zucchini or other soft vegetables, better done harder vegetables like yams, pumpkin and butternut squash. Mine like broccoli stems. Cut them open so the tender inside is exposed. Green beans are another favorite. Again, slice them open so the tender part is exposed. They will even eat the young beans inside!
2) If that does not work remove the Pleco to another tank and just keep Java Fern, Anubias and other "non-edible" plants.