Verified answer

No, plecos are considered scaleless fish and are sensitive to salt. Pickles of any kind have far too high a salt content to make a good snack for a pleco. They do, however, love fresh or frozen cucumbers and zucchini.

As a couple others have said, it would be safe to feed it cucumber (before being pickled), or zucchini or squash. The problem with pickles is the pickling process and that leaching out of the cucumber and into your water. Raw veggies are fine though.

MFK

If you are refering to a pleskosthimus(spelling wrong) cat fish that can be found in fish tanks, it is a primitive looking critter. No they don't eat pickles, nor any other fish, Because of the vinegar.

You probably saw a pleco eating a zucchini slice. Plecostomus will also eat lettuce.

Actually, live bearer salt is good for fish without scales, it helps them produce a good slime coating. However...vinegar I do not think would be a good thing to add to your tank. Maybe a cucumber slice...b4 it is pickled!