Baryancistrus

Prior to description this species was traded under the DATZ code L239. It can be distinguished from other species in the genus and other hypostomines (see below for definition of this grouping) by its uniformly black to brownish body and fin colouration with a turquoise to bluish sheen, and the acutely bent shape of midventral body plates 3-5 which form a distinctive keel running along the body, above the pectoral fins...

Prior to description this species was traded under the DATZ code L047 or the alternative vernacular name 'magnum pleco'. It can be distinguished from congeners by a combination of the following characters: presence of a broad, light-coloured (usually yellowish) distal band on the dorsal and caudal fins throughout life, slightly reduced in adults. The only other member of the genus to possess such bands is B. xanthellus but in that species they are reduced to small markings at the fin tips in adults, and the body is covered in pale, normally yellowish, spots.

This species is very similar to Hemiancistrus subviridis in appearance and the two occur sympatrically in nature, although B. demantoides is less common in the aquarium trade. Both have been marketed under the DATZ code L200 with B. demantoides sometimes referred to as 'L200 high-fin' or 'L200a', the former name in reference to its comparatively long dorsal-fin spine (average length in the type series 42.1 mm vs. 34.3 mm in H. subviridis).

It remains unconfirmed as to whether this fish represents a colour form of B. xanthellus or not since its DATZ code number of L081 is not referred to in the description paper whereas all other codes for 'gold nugget' plecos, i.e., L018, L085, L177 plus the 'Das Aquarium' code LDA060 are mentioned. In addition, one of the specimens in our images was apparently collected at São Félix do Xingu which is significantl...

The genus Baryancistrus can be distinguished from all other loricariids by possession of an enlarged membrane located posteriorly to the last branched dorsal-fin ray. This membrane may or may not reach the supporting structure of the adipose fin and in this way members can be told apart from the genera Oligancistrus, Parancistrus, and Spectracanthicus, in which the dorsal and adipose fins are completely connected, and Hemiancistrus...

Prior to description in 2011 this species was traded under the DATZ code numbers L018, L085, L077 and 'Das Aquarium' code LDA060, while a very similar-looking fish from the lower rio Xingu which has been assigned the code L081 may also represent a form of B. xanthellus but is not mentioned in the description paper. B. xanthellus can be distinguished from congeners by a combination of the following...