Another seemingly undescribed Ancistrus species that is also without l-number is this very nice one from Rio Tocantins, Brazil. With it's contrasting wormline pattern it's got great looks, and it's also a rather small species.
Name: Ancistrus sp. “Rio Tocantins”
Trade names: Tocantins Ancistrus, Tocantins bristlenose
Origin: Rio Tocantins, Brazil
Maximum TL: 10 cm / 5''
This is a rare species in the hobby, and it's availability is currently depending on a few breeders around Europe. It's sexually mature already at 5-6 cm, and quite productive. It's easy both to keep and breed, and should have a great potential to become a popular species once it gets spread around more. It shares similarities with L159 from Rio Xingu, but L159 has a pale reddish seam in it's caudal fin.