Lasiancistrus was first described as a subgenus of Ancistrus in 1904, including A. heteracanthus, A. pictus, A. mystacinus, and A. guacharote.

L. castelnaui, L. caquetae, L. guapore, L. multispinis, L. pictus, and L. scolymus are synonyms of L. schomburgkii.

[1] The species of Lasiancistrus are most commonly found in small creeks, typically in swift flow.

Lasiancistrus are most common in lower piedmont streams and are more likely to spread between rivers this way rather than through the lowlands.

[1] In nuptial males, there are fleshy tentacles on the pectoral-fin spines longer than their associated odontodes, which differentiates it from all genera except Ancistrus.

The only differences between the species are the degree of abdominal plating (itself a characteristic that is likely to be very homoplastic) and coloration.

In the rest of the species, the dorsal fin is with black spots, the body is with dark markings and light markings, if present, are usually present as blotches or thick lines (except in the Bayano River population in Panama of L. caucanus); the body is never completely dark.

In L. caucanus and L. tentaculatus, the abdomen lacks plates; between these two species, L. caucanus has whiskerlike odontodes on the corners of the snout in nuptial males and an emarginate caudal fin, while L. tentaculatus has tentacles along the anterior margin of the snout in nuptial males and a forked caudal fin.