Lasiancistrus tentaculatus, photo by K. S. Cummings
The Following is from a manuscript I recently submitted. It contains a key to all species of Lasiancustrus that will be accepted as well as descriptions of the species. I tried to get rid of them all, but the document may contain manuscript names that are unavailable for use.
Lasiancistrus is a medium-sized genus (ca. 16 species) of the Loricariidae from the Amazon, Essequibo, Orinoco, Magdalena, San Juan, Atrato, Tuyra, and Bayano River drainages and the Lake Maracaibo drainage. Lasiancistrus was described by Regan (1904) as a subgenus of Ancistrus for those species of loricariids that have hairlike odontodes as part of the evertible cheek odontodes (later called whiskerlike odontodes; Armbruster, 2004). The whiskerlike odontodes are unique among the Loricariidae (Armbruster, 2004). These odontodes are very narrow, but appear to be made out of the same material as the rest of the odontodes (enamel and dentin). Later, Lasiancistrus was raised to genus level, and many unrelated species were placed into it (Isbrückercker, 1980; Heitmans et al. 1985; Armbruster and Provenzano, 2000). The genus was diagnosed by Armbruster (1997; 2004), and the taxonomy was greatly updated by Fisch-Muller (2003).
Several taxonomic problems are still inherent in Lasiancistrus due to the fact that most species were described from few, and in one case no, specimens, and localities are imprecise. An examination of the type specimens, the original descriptions, and a little detective work has led to this revision of the genus. Based on this study, four of the 16 described species are considered valid: L. heteracanthus (Günther, 1869) (type of the genus), L. schomburgkii (Günther, 1864), L. caucanus Eigenmann, 1912, and L. guacharote (Valenciennes, 1840). In addition, two new species are described (L. saetiger and L. tentaculatus). Lasiancistrus maracaiboensis Schultz 1944, and L. mystacinus (Kner, 1854) are synonyms of L. guacharote. Lasiancistrus castelnaui (Miranda Ribeiro 1911) was originally published as a replacement name for L. pictus (Castelnau, 1855) which was preoccupied by Ancistrus pictus Kner 1854 when both species were in Hemiancistrus (Miranda Ribeiro, 1911). Lasiancistrus castelnaui, L. caquetae (Fowler, 1945), L. guapore Knaack, 2000, L. multispinis Holly, 1929, L. pictus, and L. scolymus Nijssen and Isbrückercker 1985, are synonyms of L. schomburgkii. Lasiancistrus planiceps Meek and Hildebrand, 1913, L. mayoloi (Eigenmann, 1912), and L. volcanensis Dahl, 1942, are synonyms of L. caucanus. Chaetostomus trinitatus G nthenther, 1864, is occasionally recognized in Lasiancistrus, but there were no types designated for the species. The species cannot be placed to genus based on the original description and C. trinitatus is recognized as incertae sedis in the Loricariidae. In addition, Lasiancistrus nationi was found to be a species of Ancistrus. In this paper, Lasiancistrus and its species are described and diagnosed.
Type Species. Chaetostomus heteracanthus Günthenther 1869:425, Figs. 3-4.
Adult Lasiancistrus can be separated from all other loricariids by the presence of whiskerlike odontodes on the cheek. In addition, Lasiancistrus can be separated from all other loricariids except members of the Pterygoplichthini and Ancistrini by the presence of evertible cheek odontodes; from the Pterygoplichthini by having three rows of plates on the caudal peduncle (vs. five) and a modified, bar-shaped opercle (vs. a triangular opercle); from all except Ancistrus, Dekeyseria, Exastilithoxus, Lithoxus, Neblinichthys, and Pseudolithoxus of the Ancistrini by having three rows of plates on the caudal peduncle (vs. five, rarely four); from all but Ancistrus by having nuptial males with tentacules on the pectoral-fin spines longer than their associated odontodes; from Ancistrus by having plates along the edge of the snout (vs. snout plates absent) and by maximally having transluscent tentacules on the snout that have odontodes associated with them (vs. larger tentacles without associated odontodes colored the same as the head; even female and juvenile Ancistrus have some tentacles along the snout margin); from Dekeyseria by lacking keels on the lateral plates; from Exastilithoxus and Lithoxus by having greater than 30 teeth per jaw ramus (vs. less than 10) and by having oval lips (vs. round); from Neblinichthys by lacking hypertrophied odontodes on top of the head in nuptial males; and from Pseudolithoxus by lacking long, bristle-like odontodes on the leading edge of the pectoral-fin spine.
Key to the Species of Lasiancistrus
1b....... Dorsal fin with black spots. Body with dark markings, light markings (if present) usually present as blotches or thick lines (except in ro Bayano population in Panam), body never completely dark...................................... 3
2a....... Body and fins with small white spots (although spots may be faded). Plates entirely dark or with small spots. L. schomburgkii
2b....... Body and paired fins with large white spots, dorsal fin without spots. Plates outlined in black L. saetiger
3a....... Abdomen without plates...................................................................................................... 4
3b....... Abdomen with plates in at least a small patch medial to the insertion of the pectoral-fin spines. 5
4a....... Nuptial males with whiskerlike odontodes at the corners of the snout (Fig. 2a). Caudal fin emarginate. L. caucanus
4b....... Nuptial males with tentacules along the anterior margin of the snout (Fig. 2b). Caudal fin forked. L. tentaculatus
5a....... Abdomen with plates underneath entire pectoral girdle and on abdomen.
................................................................................................................................ L. heteracanthus
5b....... Abdomen with only a couple of plates medial to insertion of pectoral-fin spines.
..................................................................................................................................... L. guacharote
Lasiancistrus caucanus Eigenmann 1912
Lasiancistrus caucanus Eigenmann 1912:11.
Hemiancistrus mayoloi Eigenmann 1912:10.
Ancistrus planiceps Meek and Hildebrand 1917:79.
Lasiancistrus volcanensis Dahl 1942: 83
Description. See genus description for more information. Morphometrics in Table 1. Largest specimen 190.4 mm SL. Abdomen naked. 21–25 (mode = 24) plates in the median series. 4-35 whiskerlike odontodes in evertible cheek mass (mode = 11, N = 49); 21-76 (mode = 39, N = 57) total hypertrophied odontodes in cheek mass.
Sexual dimorphism. Nuptial males with whiskerlike odontodes at the anterolateral corner of the snout, else as in genus description.
Most specimens available have the colors faded, but those that do have color left show little variation across the trans-Andean region they occupy and no other characteristics could be found to support any of the species listed above as synonyms. The only difference in color pattern is from specimens collected from the ro Bayano, the furthest west river in the range of L. caucanus in Panama. These specimens have the light areas of the body as spots instead of forming a light background; however, the other elements of the color pattern are as in the rest of the species. Few specimens are available from the Bayano to make comparisons, so it is unknown if this population would require separate species status.
Hypostomus guacharote Valenciennes in Cuvier & Valenciennes 1840: 508.
Ancistrus mystacinus Kner 1854: 276.
Lasiancistrus maracaiboensis Schultz 1944: 314.
Description. See genus description for more information. Morphometrics in Table 1. Largest specimen 119.5 mm SL. Abdomen naked. 23-25 (mode = 24) plates in the median series. 4-24 whiskerlike odontodes in evertible cheek mass (mode = 16, N = 26); 17-43 (mode = 25, N = 26) total hypertrophied odontodes in cheek mass.
Sexual dimorphism. Nuptial males with whiskerlike odontodes at the anterolateral corner of the snout, else as in genus description.
Lasiancistrus mystacinus was described by Kner (1854) based on a single specimen with the stated locality of "Caracas". The drainage in Caracas is the ro Tuy, and no Lasiancistrus have been reported from the Tuy. It is believed that the locality "Caracas" in Kner's work simply means where the specimens left Venezuela (R. P. Vari, pers. comm.), and that these specimens could have come from anywhere in Venezuela. The type of L. mystacinus has the plates only in the corners of the pectoral girdle as is used to diagnose L. guacharote and is considered a synonym. The only other species of Lasiancistrus in Venezuela is L. tentaculatus, which lacks plates on the abdomen and L. schomburgkii, which has more plates on the abdomen.
Lastly, Schultz (1944) described Lasiancistrus maracaiboensis as the first species of Lasiancistrus in Venezuela with an accurate type locality. These specimens also have a small patch of platelets near the insertion of the pectoral-fin spine. Kner (1854) and Schultz (1944) both mention the resemblance of L. mystacinus and L. maracaiboensis, respectively, to L. guacharote, and suggest that because of the poor description, the identity of L. guacharote was uncertain and that a new species should be described. Schultz (1944) was further restricted from viewing the types of L. guacharote and L. mystacinus by the events of World War II.
Lasiancistrus guacharote occurs in one river in the río Meta - río Orinoco drainage of Colombia. These specimens are clearly L. guacharote as they have a patch of platelets ventrally near the insertion of the pectoral-fin spines, whiskerlike odontodes at the edge of the snout, and dark spots in the dorsal and caudal fins. Two other species are known from the ro Orinoco, drainage: L. schomburgkii and L. tentaculatus. Lasiancistrus schomburgkii has white spots in the dorsal and caudal fins (vs. having dark spots in the fins), and L. tentaculatus has no abdominal plates and has tentacules along the snout instead of whiskerlike odontodes. The collection of these fishes (ANSP 128695) is from around Villavicencio, a town well connected with the aquarium export business. It is likely that these fishes result from having been introduced from the aquarium trade. It is unknown if this population is extant.
Chaetostomus heteracanthus Günther 1869.
Description. See genus description for more information. Morphometrics in Table 2. Largest specimen 149.2 mm SL. Abdomen with small platelets anteriorly. 23-25 (mode = 24) plates in the median series. 10-19 whiskerlike odontodes in evertible cheek mass (N = 3); 24-32 (N = 3) total hypertrophied odontodes in cheek mass.
Sexual dimorphism. So sexual dimorphism observed; specimens might not be mature. The holotype appears to be developing whiskerlike odontodes on the snout.
Description. See genus description for more information. Morphometrics in Table 2. Largest specimen 100.1 mm SL. Abdomen naked. 24 plates in the median series. 7-15 whiskerlike odontodes in evertible cheek mass (N = 4); 30-39 (N = 4) total hypertrophied odontodes in cheek mass.
Sexual dimorphism. No sexual dimorphism observed; specimens might not be mature.
Chaetostomus schomburgkii G nthenther 1864: 245
Hypostomus pictus Castelnau 1855: 44 Pl. 22 (Fig. 2).
Hemiancistrus castelnaui Miranda-Ribeiro 1911:58.
Ancistrus multispinis Holly 1929:119-120.
Hemiancistrus caquetae Fowler 1945:115, Figs 17-20.
Lasiancistrus scolymus Nijssen & Isbrücker 1985: 242, Figs. 1-3.
Lasiancistrus guapore Knaack 2000: 57, Fig. (unnumbered).
Description. See genus description for more information. Morphometrics in Table 3. Largest specimen 161.7 mm SL. Abdomen ranging from having no plates, to just a few plates laterally under the pectoral girdle, to having much of the anterior two thirds of the abdomen with small plates (see Comments). 23-25 (mode = 24) plates in the median series. 2-36 whiskerlike odontodes in evertible cheek mass (mode = 18, N = 61; 17-81 (mode = 21, N = 61) total hypertrophied odontodes in cheek mass.
Range. Lasiancistrus schomburgkii is found throughout much of the Amazon basin and the Upper Orinoco and Essequibo River basins (Fig. 3).
Two species of Lasiancistrus have been described in the past 20 years, L. scolymus and L. guapore (Nijssen and Isbrücker, 1985; Knaack, 2000). Lasiancistrus scolymus was based on a single individual and L. guapore was based on a single collection, and both species were described from the rio Madeira drainage of Brazil. Lasiancistrus scolymus was compared only to the holotype of L. heteracanthus and L. guapore only to the descriptions of L. scolymus and L. heteracanthus. Although some measurements were given as differences between the species in both descriptions, the results of the morphometric analysis in this study suggest that measurements cannot separate species of Lasiancistrus. The only other characteristic mentioned is the absence of plates on the abdomen in L. scolymus and the near absence of plates on the abdomen in L. guapore vs. a partially plated abdomen in L. heteracanthus. No comparisons were made with L. castelnaui or L. schomburgkii whose types are also without plates on the abdomen.
Specimens of Lasiancistrus schomburgkii from northern tributaries of the Madeira, tributaries of the Amazon upstream of the Madeira, and northern tributaries of the Amazon, the Orinoco, and the Essequibo tend to have many small, embedded plates on the abdomen, although the number of plates varies considerably, and plates are absent at least in the holotype of L. pictus. Two specimens from the ro Ucayali basin (MUSM 14313) exhibit almost the entire range of variation in abdominal plating in L. schomburgkii. One specimen (92.6 mm SL) has a single plate medial to the insertion of the right pectoral-fin spine and two medial to the left pectoral-fin spine and none in the center of the body. The other specimen (91.1 mm SL) has many small plates below the pectoral girdle and a large patch in the center of the body behind the pectoral girdle. Specimens from southeastern tributaries of the Madeira and southern tributaries of the Amazon downstream of the Madeira have no plates on the abdomen. Specimens upstream of the rio Aripuana (a southeastern tributary of the Madeira) are variable with specimens ranging from having no abdominal plates to a moderate amount. Based on the tree in Armbruster (2004), the absence of abdominal plates in Lasiancistrus is the plesiomorphic condition. Because of the variability of abdominal plating in L. schomburgkii, it is impossible to use the degree of plating to recognize any of the other described species.
The type of Ancistrus multispinis is lost, and there is no information to confirm that the species is a Lasiancistrus. The type locality is stated as 'Mercado Blein' (Holly, 1929:120), which is likely to be the Belem market. The original description describes a 148 mm long fish with 39 hypertrophied odontodes on the cheek, plates on the edge of the snout, and no tentacles, which are consistent with Lasiancistrus (Holly, 1929), however, the specimen is described as having an anal-fin ray count of I4 while most Lasiancistrus are I5. A count of I4 is rare in Lasiancistrus, but is occasionally present. The species could be considered incertae sedis in the Ancistrini; however, the description is consistent with a Lasiancistrus, and I prefer to leave it as a Lasiancistrus. Both the rio Tocantins and the rio Capim have their mouths near Belem making it possible that the species is either L. schomburgkii, which is from the Tocantins or the population described below as L. saetiger, which is described from the Capim. Holly (1929) describes the color as light brown with a darker back and brown fins. The specimens of L. saetiger are clearly spotted whereas L. schomburgkii is often entirely brown. Based on color, range, and that the description of the species is not inconsistent with L. schomburgkii, I am recognizing A. multispinis Holly as a synonym of L. schomburgkii.
The type of Lasiancistrus caquetae is very small (41.9 mm SL) and in poor condition. The specimen is entirely dark brown, seemingly the same as when it was described (Fowler, 1945). The only other described species that would likely be found the area where L. caquetae was collected are L. heteracanthus (which has dark spots on the fins) and L. schomburgkii. The original color description suggests that the species is not L. heteracanthus. Unfortunately, I have examined no other specimens from the Caqueta River; however, based on the original description of the lack of spots on the fins, it is most likely that L. caquetae is also a synonym of L. schomburgkii.
Some of the specimens examined from southern Amazonian tributaries have a couple of the teeth replaced by whiskerlike odontodes. Armbruster and Page (1996) speculated that the elongate, unicuspid teeth of nuptial male Hypostomus ammophilus were the result of a pleiotropic affect of the elongation of the body odontodes in nuptial males. Thus, there may be some correlation between the development of the integumentary teeth and the oral teeth. This correlation may also explain why some of the teeth in Lasiancistrus schomburgkii may be replaced by whiskerlike odontodes.
Description. See genus description for more information. Morphometrics in Table 3. Largest specimen 147.6 mm SL. Abdomen naked. 23–25 (mode = 24) plates in the median series. 1-26 whiskerlike odontodes in evertible cheek mass (mode = 5, N = 29); 12-60 (mode = 36, N = 31) total hypertrophied odontodes in cheek mass.
Lasiancistrus guacharote, L. schomburgkii, and L. trinitatus were placed in Guyanancistrus by Isbrücker ckercker et al. (2001), and Guyanancistrus was placed in the synonymy of Pseudancistrus by Armbruster (2004). Lasiancistrus guacharote and L. schomburgkii are clearly members of Lasiancistrus. The description of L. trinitatus is poor; however, Günther (1864) states that it has four total anal-fin rays while Lasiancistrus almost always has six. There are no known specimens of Lasiancistrus or Pseudancistrus from Trinidad, and the only loricariids known from the island are Hypostomus robinii and a species of Ancistrus. Because there are no types of the species, the species should be listed as Chaetostomus trinitatus Günther 1864, incertae sedis.
Contrary to the case presented by many other members of the Ancistrini being examined, the ranges of most of the species of Lasiancistrus are quite broad. The species with the greatest range is L. schomburgkii, which occupies most of the Amazon basin and the upper Orinoco and Essequibo basins as well. The species of Lasiancistrus are most commonly found in small creeks, typically in swift flow. However, some of the streams where Lasiancistrus can be found are in the lowlands, and hypoxia has been observed in one such stream (cano Maraca, rio Portuguesa - rio Orinoco drainage). This suggests that lowlands are not a barrier to the movement of the species.
The biogeography of Lasiancistrus suggests that lowland fishes can fairly easily breach the barriers between the Orinoco and Essequibo and the Amazon. The range of L. schomburgkii is similar to Hypostomus hemicochliodon, which also makes it into the upper Orinoco (but not into the Essequibo). The two species have similar habitat preferences, occurring in the swift sections of otherwise lowland streams.
Also curiously within Lasiancistrus schomburgkii is that those populations with the presence of plates on the abdomen (likely the derived condition based on Armbruster, 2004) are found in an arc that includes the northern Amazonian tributaries, the upper Orinoco and the Essequibo rivers while the plesiomorphic populations are from the southern Amazonian tributaries. Lasiancistrus are most common in lower piedmont streams. Due to the range of the plated and unplated populations of Lasiancistrus, it is likely that L. schomburgkii dispersed via stream capture events of these piedmont streams rather than crossing the lowlands and the Amazon.
The function of tentacules on the snouts of nuptial male Lasiancistrus tentaculatus and the pectoral fins of all Lasiancistrus and Ancistrus is unknown. Sabaj et al. (1999) speculated that the tentacles of Ancistrus are larval mimics that could potentially trick females into believing that males have larvae in the nest when they do not. Indeed, male Ancistrus are often found with larvae the size of their tentacles in their nests (see Sabaj et al., 1999 for review). Spawning in Lasiancistrus has not been reported, and members of Lasiancistrus are rarely found in the aquarium trade; however, it would be reasonable to speculate that the tentacules are mimicking a younger larva than the tentacles of Ancistrus. Although the larval mimicry hypothesis for Ancistrus and Lasiancistrus has not been tested, it is likely that the behavioral ecology of these species is quite interesting.
No morphometric, meristic, or skeletal differences could be found among the species of Lasiancistrus. The only differences between the species are the degree of abdominal plating (itself a characteristic that is likely to be very homoplastic) and coloration. The difficulty in using abdominal plating is underscored by L. schomburgkii, which has all of the observed character states for the genus. The only major difference between L. caucanus and L. guacharote is that L. caucanus has a naked abdomen and L. guacharote has a few small plates at the insertion of the pectoral-fin spine. Although this character was not useful in separating populations of L. schomburgkii, it was used to separate L. caucanus and L. guacharote because there was also geographic concordance.
The only major characteristic to be found other than color and abdominal plating between the species is the nuptial male condition of Lasiancistrus tentaculatus. Males of L. tentaculatus develop tentacules along the anterior margin of the snout while all other Lasiancistrus develop whiskerlike odontodes at the anterior corners of the snout. It is unknown how the tentacules or the whiskerlike odontodes are used. Presence of whiskerlike odontodes on the cheek does not appear to be sexually dimorphic, although males may have longer ones.
Armbruster, J. W. 1997. Phylogenetic relationships of the sucker-mouth armored catfishes (Loricariidae) with particular emphasis on the Ancistrinae, Hypostominae, and Neoplecostominae. Unpublished Ph.D. Dissertation, University of Illinois, Urbana-Champaign. 408p.
_____. 2003. Peckoltia sabaji, a new species from the Guyana Shield (Siluriformes: Loricariidae). Zootaxa, 344, 1-12.
_____. 2004. Phylogenetic relationships of the suckermouth armored catfishes (Loricariidae) with emphasis on the Hypostominae and the Ancistrinae. Zoological Journal of the Linnean Society, 141, 1-80.
_____& F. R. Provenzano. 2000. Four new species of the suckermouth armored catfish genus Lasiancistrus (Loricariidae: Ancistrinae). Ichthyological Exploration of Freshwaters, 11, 241-254.
Eigenmann, C. H. 1912. Some results from an ichthyological reconnaissance of Colombia, South America. Part I. (Contribution from the Zoölogical Laboratory of Indiana University, No. 127.). Indiana University Studies: 1-27.
Fernndez-Yépez, A. 1972. Analisis ictiologico del complejo hidrografico (04) "Río Yaracuy". Direccion de Obras Hidraulicas, Ministerio de Obras Publicas, Republica de Venezuela. 25 p.
Fisch-Muller, S. 2003. Subfamily Ancistrinae. Pp. 373-400. In: Reis, R. E., Kullander, S. O. & Ferraris, C. J. Jr. (Eds.). Check List of the Freshwater Fishes of South and Central America, EDIPUCRS, Porto Alegre. 627 p.
Fowler, H. W. 1945. Colombian zoological survey. Pt. I.--The freshwater fishes obtained in 1945. Proceedings of the Academy of Natural Sciences of Philadelphia, 97: 93-135.
Heitmans, W. R. B, H. Nijssen, & 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). Bijdragen tot de Dierkunde 53: 33-48.
Holly, M. 1929. Einige neue Fischformen aus Brasilien. Anzeiger der Mathematisch- Naturwissenschaftlichen Classe der Kaiserlichen Akademie der Wissenschaften in Wien, 66: 117-120.
Isbrücker, I. J. H. 1980. Classification and catalogue of the mailed Loricariidae (Pisces, Siluriformes). Verslagen en Technische Gegevens, Universiteit van Amsterdam, 22, 1-181.
_____, I. Seidel, J. P. Michels, E. Schraml, & A. Werner. 2001. Diagnose vierzehn neuer Gattungen der Familie Loricariidae Rafinesque, 1815 (Teleostei, Ostariophysi). Datz - Sonderheft, 2, 17-24.
Knaack, J. 2000a. Ein weiterer neuer Harnischwels aus dem Rio Guaporé: Lasiancistrus guapore n. sp. Aquaristik Aktuell, 2000 (9-10): 56-61.
Kner, R. 1854 Die Hypostomiden. Zweite Hauptgruppe der Familie der Panzerfische. (Loricata vel Goniodontes). Denkschriften Akademie der Wissenschaften in Wien, 7: 251-286.
Leviton, A. E., R. H. Gibbs Jr., E. Heal, & H. E. Dawson. 1985. Standards in herpetology and ichthyology: Part I. Standard symbolic codes for institutional resource collections in herpetology and ichthyology. Copeia, 1985, 802-832.
Miranda Ribeiro, A. de. 1911. Fauna brasiliense. Peixes. Tomo IV (A) [Eleutherobranchios Aspirophoros]. Arquivos Museu Nacional Rio de Janeiro. 16: 1-504.
Nijssen, H. & I. J. H. Isbrückecker. 1985. Lasiancistrus scolymus, a new species of mailed catfish from Rio Aripuanã, Est. Mato Grosso do Sul, Brazil (Pisces, Siluriformes, Loricariidae). Bijdragen tot de Dierkunde, 55: 242-248.
Pietsch, T.W. (ed.). 1995. Historical portrait of the progress of ichthyology, from its origins to our own time by Georges Cuvier. A.J. Simpson (translator). John Hopkins Univ. Press, Baltimore, MD. 366 p.
Regan, C. T. 1904. A monograph of the fishes of the family Loricariidae. Transactions of the Zoological Society of London, 17: 191-350.
Sabaj, M. H., J. W. Armbruster, & L.M. Page LM. 1999. Spawning in Ancistrus with comments on the evolution of snout tentacles as a novel reproductive strategy: larval mimicry. Ichthyological Explorations of Freshwaters, 10: 217-229.
Schaefer, S. A. 1986. Historical biology of the loricariid catfishes: phylogenetics and functional morphology. Unpublished Ph. D. Dissertation, The University of Chicago
_____ 1997. The neotropical cascudinhos: systematics and biogeography of the Otocinclus catfishes (Siluriformes: Loricariidae). Proceedings of the Academy of Natural Sciences of Philadelphia, 148: 1-120.
Schultz, L. P. 1944. The catfishes of Venezuela, with descriptions of thirty-eight new forms. Proceedings of the United States National Museum, 94: 173-338.
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.