The L90 is also known as the Papa Pleco because it's one of the larger species available in the hobby growing up to 30 cm (12 inches)
There are several colour variants of this fish ranging from a plain dark, slate grey of L90, to a 'scribbled' pattern a little like a Royal plec on L90a
L90b is a plain brown variant of the Papa Pleco which has also been asigned LDA28
L90c and L90d, with a red and green sheen were previously thought to also be colour variants of a seperate species numbered L203 but are now considered to be L90 variants with L90d being the juvenile form of L90c
On all variants, the tail usualy has a white flash and has elongated tips.
Papa Plecos eat algae as youngsters but like most plecs also require some protien in their diet in the form of sinking catfish pellets, bloodworm etc.
As they are a Panaque, they also need wood in their diet which should be replaced every couple of months to ensure it contains enough of the nutrients they requre.
Like most plecs, they have a high oxygen requirement, so a powerhead and/or air stone is vital as is good filtration because they produce a lot of waste but are sensitive to nitrites.