This is my pleco Zeus. He's four years old roughly and he's in my American cichlid aquarium. I think he's a male; females are rounder and less slender than males.
L330 plecos are carnivorous fish so I feed him Hikari Massivore Delite each day (each pellet has as much protein as 1.8 goldfish) and a slice of carrot every now and then. The excess carrot skin is fed to my nightcrawlers.
My retailer told me that he's fully grown when they gave him to us. He hasn't grown noticeably since I got him over a year ago but he has gotten fatter. He was double bagged and the water from the bag had to be poured into the tank because he would stick to the net. When close up you can see his little spikes and plates across his body.
My opinion on plecos is that they are great fish for all hobbyists. Beginners can start with smaller species such as the bristlenose pleco or the gold nugget pleco. As they become more experienced with keeping plecos they can begin keeping larger ones like Zeus. I know someone who kept and raised a common pleco since his childhood. His pleco recently died at the grand age of 42!
Plecos are great fish and can be quite funny sometimes too. When they become comfortable with their environment they'll exhibit very interesting, fun behaviours and will become less nocturnal and shy.