got one of 6 cm (new one, bought it last week) (must say, they're more beautiful young, like most beings, lol ;-),
the other (the one on the images) is pretty big compared the new one, can't measure him right now, but I'd say he's around 12 cm (at least), according to a book of mine, it doesn't get bigger than 20 cm in an aquarium,
I sure hope mine stops growing, cause he's in a 54 liter tank (61 x 31 x 36 cm) ... (and he grew fast and big compared to the new one)
so they're called
Sailfin pleco's, did some research ;-)
- The Sailfin Pleco was first described in 1854 by Kner as Ancistrus gibbiceps. It was renamed Pterygoplichthys gibbiceps in 1980.
~ The scientific name Glyptoperichthys gibbiceps became valid in 2003.
I've seen some pics where they really have huge back-fin (therefore their name...):
source:
Gibbiceps
but mine hasn't got such a big and rounded fin... probably not the best breed...