Two German magazines began featuring newly
discovered loricariids in their magazines some time ago and since these
spp. were not yet described to science they began assigning them "L
numbers". The Duetsch magazine "DATZ (Die Aquarien und
Terrarienzeitschrift)" started with the designation L1 for the sp. which
has now been described as Glyptopterichthys joselimaianus. So now L1 is
retired. The Duetsch magazine "Das Aquarium" also began to run a similar
feature in its magazine and labeled the fishes as LDA. The DATZ L system
is somewhere above L209 and the LDA system is above LDA26.
Along came the Aqualog series of books and they published a book with all the known L numbers and photos or drawings of each fish. This makes things a lot easier since not all of us have access to back issues of Duetsch aquarium magazines. There are apparently problems though because not all of the photos in the Aqualog book match the species in the photos that ran in the original magazines. So sometimes it is necessary to note where you L number is coming from (magazine or book).
New species of Corydoras are now being assigned "C Numbers". These fish can be found in both the German magazine Das Aquarium and the new Aqualog book "All Corydoras C Numbers".