L. caucanus Eigenmann 1912
L. caquetae (Fowler 1945)1
L. guacharote (Valenciennes 1840)
L. heteracanthus (Günther 1869)
L. maracaiboensis Schultz 1944
L. mayoloi (Eigenmann 1912)
L. multispinis (Holly 1929)
L. mystacinus (Kner 1854)
L. nationi Fernandez-Yepez 1976
L. pictus (Castelnau 1855)
L. planiceps (Meek and Hildebrand 1913)
L. schomburgkii (Günther 1864)
L. scolymus Nijssen and Isbrücker 1985
L. snethlageae (Steindachner 1911)
L. trinitatus (Günther 1864)
L. volcanensis Dahl 1941

Lasiancistrus is diagnosed by two unique characteristics: a strut proceeding posteriorly from the anterior process of the pterotic-supracleithrum mesial to the main body of the pterotic-supracleithrum and the presence of cheek whiskers.  Other characteristics considered to be synapomorphic for Lasiancistrus are: three branchiostegals, a short ventral process on the quadrate for articulation with the canal plate, a maximum forward position of the opercle at the posterodorsal corner of the quadrate, three rows of plates between the suprapreopercle and the exposed opercle, the ventral border of the orbit formed entirely by the sixth infraorbital, and exposure of the first anal fin pterygiophore

Small- to medium-sized loricariids typically colored dark brown (almost black) with some mottling on body and fins.  The abdomen is dark, but not as dark as the sides.  There are some very elongate, very thin odontodes on the cheek and sometimes on the opercle that are like a cat's whiskers in addition to the long, stout, evertible cheek odontodes.  Abdomen naked.  Caudal fin slightly emarginate with the lower lobe longer than the upper.  Four or more predorsal plates; nuchal plate and dorsal fin spinelet are exposed.  Three rows of plates on the caudal peduncle.

Males have elongated odontodes along the snout anterior of the cheek odontodes and tentacules on the snout margin and pectoral fin spine.  The tentacules on the snout may be branched.  Males also seem to possess longer and more numerous whiskers.

No other loricariid has cheek whiskers.  Breeding male Lasiancistrus are readily identifiable from all other loricariids by the presence of small fleshy, branched tentacules on the snout which are longer than their associated elongated odontodes (in Ancistrus the tentacles are much larger and are not associated with odontodes).  Most similar to Ancistrus (from which it differs by having plates on the snout), Dekeyseria (from which it differs by lacking highly keeled lateral plates), and Neblinichthys (from which it differs by lacking incredibly elongated odontodes on the top of the snout of breeding males).

Lasiancistrus typically is found in small creeks to small rivers in flowing water.

The range of Lasiancistrus is probably only along the Andes in piedmont streams, but a few species are described from outside of that range (further research may reveal these species to not be Lasiancistrus).

Lasiancistrus sensu Isbrücker (1980) and Heitmans et al. (1983) is clearly a polyphyletic assemblage.  Pseudancistrus genetsetiger and P. papariae were included in Lasiancistrus by Isbrücker (1980), but I have examined the types and they are clearly of species of Pseudancistrus. Lasiancistrus niger, L. brevispinnis, and L. longispinnis are almost certainly misplaced by Heitmans et al. (1983).  The species clearly have five rows of plates on the caudal peduncle and lack whiskerlike odontodes on the snout.  In addition, L. niger has long odontodes along the snout.  The combination of these characters suggest that L. niger also belongs in Pseudancistrus.  I have examined paratypes of L. brevispinnis and they are virtually identical to Hemiancistrus  sp. on the Hemiancistrus page except that they have shorter cheek odontodes.  I have not examined types of L. longispinnis, but the description suggests that the species is very similar to L. brevispinnis.  I suggest that L. brevispinnis and L. longispinnis be placed in Hemiancistrus.

Also, Lasiancistrus carnegiei, L. daguae, L. fuessli, and L. setosus are all as described for Chaetostoma and are placed therein.  The placement of Chaetostoma daguae is difficult, but it appears to be in the subgenus Cordylancistrus.  The remainder of the species have elongate pectoral fin spines and only a single, maybe two extremely elongate odontodes in the cheek mass.  They also have adipose and anal fins suggesting that they belong in the subgenus Dolichancistrus.

Only Lasiancistrus caucanus, L. guacharote, L. heteracanthus , L. maracaiboensis, L. mayoloi, L. mystacinus, L. nationi, L. pictus, L. planiceps, and L. scolymus could be confirmed as possessing whiskerlike odontodes.  There is not enough information in the descriptions of L. multispinis, L. scomburgkii, and L. snethlageae to confirm or deny whether they have whiskerlike odontdes, but, from the descriptions, it would appear as if these species are improperly placed in Lasiancistrus.

The placement of Peckoltia caquetae (Fowler, 1945) is difficult.  Given that there are three rows of plates on the caudal peduncle, its placement either in Peckoltia, as suggested by Isbrücker (1980), or Hemiancistrus, as suggested by Fowler (1945), is not possible.  The specimen does not have whiskerlike odontodes, but it is small (42.8 mm SL), and juvenile Lasiancistrus do not always have the modified odontodes.  Given that the specimen is very dorsoventrally flattened (as in most Lasiancistrus) and lacks sharp keels on the lateral plates, the species is best placed in Lasiancistrus.

In addition, four new species of Lasiancistrus have been submitted by Armbruster and Provenzano.  I feel that these species are not related to Lasiancistrus and deserve separate generic status; however, Provenzano feels that they do belong in Lasiancistrus; thus, we acted conservatively and described the species in Lasiancistrus.  Go to new genus page for more information.

Armbruster, J.W. 1997. Phylogenetic relationships of the sucker-mouth armored catfishes (Loricariidae) with particular emphasis on the Ancistrinae, Hypostominae, and Neoplecostominae. Unpubl. Ph.D. dissertation. University of Illinois, Urbana-Champaign. 409 pp.

Armbruster, J.W. and F. Provenzano. Submitted.  Four new species of the suckermouth armored catfish genus Lasiancistrus (Loricariidae: Ancistrinae). Ichthyological Exploration of Freshwaters.

Heitmans, W.R.B., H. Nijssen, and I.J.H. Isbrücker. 1983. The mailed catfish genus Lasiancistrus Regan, 1904, from French Guiana and Surinam, with descriptions of two new species (Pisces, Siluriformes, Loricariidae). Bijd. tot de Dierkunde, 53:33-48.

Isbrücker, I.J.H. 1980. Classification and catalogue of the mailed Loricariidae (Pisces, Siluriformes). Versl. Techn. Gegevens, Univ. van Amsterdam No. 22, 181 pp.

Sabaj, M.H., J.W. Armbruster, and L.M. Page. Spawning in Ancistrus with comments on the evolution of snout tentacles as a novel reproductive strategy: larval mimicry. Ichthyological Exploration of Freshwaters.