By David E. Boruchowitz
Two aquarium favorites in the genus Baryancistrus have graduated from L numbers to scientific names. The gold nugget pleco, known by three L numbers, L18, L85, and L177) has been described as B. xanthellus. The mango pleco, called L47, is now B. chrysolomus.
L numbers have long been used to keep track of loricariid catfishes, commonly called plecos, that become popular in the aquarium hobby before scientists describe them. This pair of related species are among the plecos prized for their distinctive coloration. Both have yellow margins to the dorsal and caudal fins as juveniles. B. xanthellus displays yellow spots all over the body and fins while the spots on B. chrysolomus are very faint. Both species feed primarily on algae and require a vegetable-based diet in captivity.