Taxonomy & naming
This is an undescribed form: no scientific name, authority or type material stands behind it, and its identity and range are not documented in the sources the atlas uses. L519 is an L-number, the coding system DATZ magazine began in 1988 for imported loricariids that could not be identified. Three sellers list the form: Imperial Tropicals as L519 Ancistrus sp. "Rio Itenez", Aqua Huna as the L519 honeycomb bristlenose pleco, and Dan's Fish as the L519 honeycomb bushynose pleco "Rio Itenez". Imperial Tropicals says it was discovered in 2019.
Morphology
Imperial Tropicals describes an ornate black honeycomb pattern over a tan or sometimes gold body and fins, and says females look darker than males, though both lighten and darken with mood. Dan's Fish says juveniles are brown and develop a honeycomb pattern with an orange tinge as they mature. Like other Ancistrus, the genus carries branched tentacles on the snout of adult males (genus-level).
Habitat
Dan's Fish gives the natural range as the Rio Madeira, Rio Mamoré and Rio Iténez. The Iténez, also called the Guaporé, is a Madeira tributary on the Bolivia–Brazil border. Ancistrus as a genus are widespread in South American rivers and streams (genus-level). Collection details for this form are not documented in the atlas's sources.
Feeding
Dan's Fish calls Ancistrus great algae eaters. Like other Ancistrus, the genus grazes algae and biofilm and accepts vegetable foods and sinking pellets (genus-level).
Mating
Ancistrus are cave spawners in which the male guards the clutch (genus-level). Spawning of this form is not documented beyond the seller note on captive breeding.
Breeding
Dan's Fish lists its stock as hobbyist bred and raised in the USA. No further breeding record for this form is held by the atlas.
In the aquarium
Dan's Fish gives an estimated shipping size of 1–2.5 inches (about 1–2.5 in) and an adult size of around 4–5 inches (about 4–5 in), and calls the genus hardy and smaller than the common pleco. Imperial Tropicals notes that the form is desirable despite being newly discovered. These figures are seller statements only. Provide caves and driftwood, as for other Ancistrus.
Conservation
No IUCN assessment exists for this undescribed form. Its range and numbers are not documented, so its conservation status cannot be stated.