one of my 9inch plecos used to suck on my 12inch oscar, it wouldn't stop even when the oscar beat the snot out of it, I had to take the pleco out of the tank....I'm not saying theres not a way to make it stop though, you could maybe try feeding it some lettuce or cucumber.
my L600 does not suck the aros. He eats only peeled shrimp. does not seem to be interested in veggies ... he loves destroying the sponge filters though =(
SLIMECOAT
Is a mucous created by the continual replacement of glandular cells know in the fishes skin hat produce a glycoprotein which is called mucin.
Areas of the amazon where a number of plecos exist there is little in the line of protein based foods.Plecs are very adaptable to feeding on availiable food sources and one is the mucus coating of other fish,There is good evidence of these fish doing this in the wild and plenty of evidence of these fish doing this in captivity.There It really would not be a suprise to find that mucus feeding is a common feeding method in many Loricariidae catfishes.These fish are really not obligate herbivores. -Anne