The L-number system is a semi-scientific classification system of catfish based on photographs of shipments of tropical catfish of the family Loricariidae published by the German aquarium magazine DATZ (Die Aquarien- und Terrarienzeitschrift (The Aquarium and Terrarium Magazine)).
The L-number system is a partly scientific categorization method of catfish derived from photographs of shipments of tropical catfish belonging to the family Loricariidae published in the German aquarium magazine DATZ (Die Aquarien- und Terrarienzeitschrift).