A Key to the Genera of Loricariidae


Hemiancistrus sp., photo by M.H. Sabaj



    This key provides a means of identifying the genera of Loricariidae except those of the Hypoptopomatinae or the Loricariinae. All loricariids can be entered into this key, but hypoptopomatines and loricariines will terminate at the subfamilial level. Schaefer (1997) provides a key for Hypoptopomatinae, and Burgess (1989) provides keys for Loricariinae (although the key to the Loricariini does not work well).

    To go to the next step in the key, hit the number on the right.  To view information for the genus your search terminates on, click the genus name.  To view a characteristic used in the key for which an illustration is available, click on "VIEW".  Letters after view refer to letters in the illustration.


 
1a. Body behind head incompletely plated dorsally and laterally. 2
1b. Body behind head completely plated dorsally and laterally (plates may be absent ventrally). 3
     
2a. Plates anterior to dorsal fin absent. No hypertrophied odontodes on leading edge of pectoral fin spine in nuptial males (VIEW). Lithogenes
2b. Plates anterior to dorsal fin present. Hypertrophied odontodes on leading edge of pectoral fin spine in nuptial males (VIEW). Hemipsilichthys nudulus
     
3a. Ventral surface of the pectoral girdle exposed (i.e. supporting odontodes) mesial to the coracoid strut (VIEW - C&D). Hypoptopomatinae
3b. Ventral surface of the pectoral girdle covered in skin or plates mesial to the coracoid strut (coracoid strut may be exposed; plates may cover the pectoral girdle, but the odontodes are supported by the plates and not the girdle - VIEW - A&B). 4
     
4a. Caudal peduncle dorsoventrally flattened; rectangular in cross-section (VIEW). Adipose fin absent. Loricariinae
4b. Caudal peduncle not dorsoventrally flattened; oval, round, or triangular in cross-section (if caudal peduncle is depressed, it is never rectangular). Adipose fin absent or present. 5
     
5a. Edge of snout naked (VIEW - A). 6
5b. Edge of snout covered with plates (VIEW - B). 9
     
6a. Cheek plates evertible to 75 degrees or greater (VIEW - B). Nuptial male with no hypertrophied odontodes along snout (Fig. 6a-c) and no thick flesh present on posterior process of cleithrum. 7
6b. Cheek plates not evertible (VIEW - A). Nuptial male with hypertrophied odontodes present along snout (Fig. 6d) and thick flesh present on posterior process of cleithrum. (The apparent loss of plates on the snout in these species is actually due to thick flesh covering the plates and occurs only in nuptial males.). 8
     
7a. No fleshy tentacles on snout (VIEW). Chaetostoma (part)
7b. Fleshy tentacles on snout (best developed in males, but females possess some small tentacles at edge of snout; VIEW). Ancistrus
     
8a. Plates on abdomen. Dorsal fin spinelet absent (VIEW - location of dorsal-fin spinelet) Isbrueckerichthys
8b. No plates on abdomen. Dorsal fin spinelet present as small, rectangular, platelike structure (VIEW - C&D). Hemipsilichthys
     
9a. Postdorsal ridge of 3+ median, unpaired preadipose plates present (adipose fin may or may not be present (VIEW - C). 10
9b. Postdorsal ridge absent or restricted to usually 1 (occasionally 0 or 2) median, unpaired preadipose plates (VIEW - A&B). 12
     
10a. Adipose-fin membrane and spine absent. (VIEW). Corymbophanes
10b. Adipose-fin membrane and spine present present. 11
     
11a. Body strong and massive, usually attaining large sizes around 200 mm SL (maximum recorded 270.3 mm SL); orbits large (18.0-24.5% of head length); dorsal-fin membrane extended posteriorly and contacting first preadipose plate; usually seven infraorbital canal plates. Delturus
11b. Body slender and elongate, usually attaining sizes smaller than 120 mm SL (maximum recorded 156.4 mm SL); orbits small (8.6-16.9% of head length); dorsal-fin membrane not or slightly extended posteriorly but never in contact with first preadipose plate; usually five or six infraorbital canal plates. Hemipsilichthys gobio
     
12a. Eight or more branched dorsal fin rays. 13
12b. Seven branched dorsal fin rays. 22
   
13a. More than 60 teeth per jaw ramus. Nuchal plate covered by plates and dorsal-fin spinelet covered by skin, both rarely supporting odontodes. No plates on the abdomen. Usually no strong keels on lateral plates [Cordylancistrus platycephalus develops keels on the plates , but they are not well-developed]. 14
13b. Fewer than 60 teeth per jaw ramus. Nuchal plate and dorsal-fin spinelet exposed, supporting odontodes. Usually with plates on abdomen (plates may develop late ontogenetically); if specimen is large (> 50 mm SL) and has no plates on abdomen, lateral plates have strong keels formed by long, stout, sharp odontodes. 17
     
14a. Anal and adipose fins absent (VIEW). Leptoancistrus
14b. Anal and adipose fins present. 15
     
15a. One or two of the cheek odontodes greatly elongated and thickened, longer than head. Dolichancistrus
15b. All cheek odontodes of approximately the same length. 16
     
16a. Cheek odontodes very short (VIEW - A). Chaetostoma platyrhynchus
16b Cheek odontodes longer (VIEW - B). Cordylancistrus
     
17a. Adipose fin absent. 18
17b. Adipose fin present. 19
     
18a. Lateral plates with well-developed keels.  Pterotic-supracleithrum greatly expanded, longer than tall (VIEW - C). Acanthicus
18b. Lateral plates without well-developed keels.  Pterotic-supracleithrum not greatly expanded, taller than long (VIEW - A&B). Pogonopoma (part)
 
19a. Usually more than 10 teeth per jaw ramus. Pterygoplichthys
19b. Usually ten or fewer teeth per jaw ramus. 20
     
20a. Lower lip round (VIEW - C&D). Fimbriae present above upper lip (VIEW - D). Supraoccipital raised into a crest (VIEW). Only 1-4 teeth per premaxilla that are extremely long. Leporacanthicus
20b. Lower lip oval (VIEW - A&B). Frimbriae absent above upper lip (VIEW - A-C). Supraoccipital not raised into a crest. Usually more than 4 teeth per premaxilla; teeth moderately long. 21
     
21a. 8-9 dorsal-fin rays. Pterotic-supracleithrum not expanded (VIEW - A). Found in the Amazon and Orinoco systems, and in the Guyanas. Pseudacanthicus
21b. 9-11 dorsal-fin rays. Pterotic-supracleithrum moderately expanded (VIEW - B). Found in the Paraná and São Francisco systems. Megalancistrus
     
22a. Dorsal fin with membrane of last ray expanded posteriorly, attaching to preadipose plate or the adipose spine (VIEW - B). 23
22b. Dorsal fin with membrane of last ray not expanded posteriorly, not attaching to preadipose plate or the adipose spine (VIEW - A). 25
     
23a. Gill openings large. Parancistrus
23b. Gill openings restricted. 24
     
24a. Premaxillas long, nearly forming straight line at union; more than 26 teeth per jaw ramus. Baryancistrus (part)
24b. Premaxillas short, forming acute angle at union; 26 or fewer teeth per jaw ramus. Spectracanthicus (includes Oligancistrus)
     
25a. Teeth large, spoon-shaped with little or no stalk (VIEW - B). 26
25b. Teeth viliform (threadlike) or large with long stalk (VIEW - A&C). 27
     
26a. Cheek without elongated, evertible odontodes (VIEW - A). Hypostomus cochliodon group
26b. Cheek with elongated, evertible odontodes (VIEW - B). Panaque (part)
     
27a. Cheek plates not evertible (not loosely embedded in connective tissue; firmly attached to suspensorium), if hypertrophied odontodes are present on cheek, their supporting plates are fairly immobile (VIEW - A). Cheek plates covering anteroventral corner of the opercle do have slight mobility, but can not be held at right angle to head. 28
27b. Cheek plates evertible (loosely embedded in connective tissue, not firmly attached to suspensorium), usually with hypertrophied odontodes (VIEW - B). Evertible cheek plates and odontodes can be held almost at right angle to head. 45
     
28a. Adipose fin absent (raised preadipose plate may be present in Rhinelepis). 29
28b. Adipose fin present (an occasional, aberrant specimen may lack an adipose fin). 34
     
29a. 1 unbranched and 4 branched anal fin rays. Teeth spoon-shaped (VIEW - B; teeth often smaller than in typical members of the Hypostomus cochliodon group). Hypostomus levis
29b. 1 unbranched and 5 branched anal fin rays. Teeth narrow (VIEW - A&C). 30
     
30a. Spinelet of dorsal fin not well developed (visible only as rectangular patch of odontodes - VIEW - C&D). Anus well separated from anal fin spine. Eye bilobed (dorsal flap of iris present - Fig. 27a). 31
30b. Spinelet of dorsal fin well developed (visible as triangular bone with odontodes - VIEW - B). Anus almost in contact with anal fin spine. Eye not bilobed (dorsal flap of iris absent - Fig. 27b). 32
     
31a. Hypertrophied odontrodes present along snout margin in nuptial males (Fig. 6d). Pareiorhaphis (part)
31b. Hypertrophied odontodes absent along snout margin in all individual (Fig. 6a-c). Pareiorhina
     
32a. One medium-sized plate posterior to pterotic-supracleithrum (VIEW - A). Patch of hypertrophied odontodes on cheek in adult. Lateral plates well keeled. Tall ridges on pterotic-supracleithrum. Pseudorinelepis
32b. Patch of small plates just posterior to pterotic-supracleithrum (VIEW - B). No patch of hypertrophied odontodes on cheek in adult. Lateral plates not- or weakly-keeled. Short ridges on pterotic-supracleithrum. 33
     
33a. Plate present between opercle and pterotic-supracleithrum (VIEW - B). Exposed part of sphenotic not in contact with orbit (VIEW - B). Abdomen fully plated in adults. Rhinelepis
33b. Plate absent between opercle and pterotic-supracleithrum (as in VIEW - A). Exposed part of sphenotic in contact with orbit (VIEW - A). Abdomen naked, or with a few scattered areas of plates. Pogonopoma (part)
     
34a. 1 unbranched and 5 branched anal-fin rays. 35
34b. 1 unbranched and 4 or fewer branched anal-fin rays. 41
     
35a. Abdomen with no small plates. 36
35b. Abdomen with at least some small plates (plates may be deeply embedded such that only the odontodes pierce the skin). 39
     
36a. Caudal peduncle with 4-5 rows of plates (VIEW - A).  37
36b. Caudal peduncle with at least one column of only 3 rows of plates (VIEW - B). 38
     
37a.  Hypertrophied odontodes on snout absent in all adults (Fig. 6a-c). Hypertrophied odontodes on cheek do not fold into a groove underneath opercle (Fig. 34a). Lateral section of cleithrum not well developed (Fig. 35a). Pareiorhaphis? (Undescribed species of uncertain taxonomic relationships)
37b. Hypertrophied odontodes on snout present in all adults (Fig. 6d). Hypertrophied odontodes present on cheek that fold into a groove underneath opercle (Fig. 34b). Lateral section of cleithrum not well developed (Fig. 35b-2). Pseudancistrus(part)
     
38a. Body narrow, cigar-shaped (Fig. 38). Hypertrophied odontodes absent on cheek of nuptial male (Fig. 6a-c). Suprapreopercle absent (Fig. 39a). Kronichthys
38b. Body wide (Fig. 2). Hypertrophied odontodes present on cheek of nuptial male (Fig. 6c). Suprapreopercle present (Fig. 39b). Pareiorhaphis (part)
     
39b. Spinelet of dorsal fin well developed (visible as triangular bone with odontodes; VIEW - B). Anus almost in contact with anal fin spine. Eye not bilobed (dorsal flap of iris absent - VIEW - B). Odontodes on the lateral plates in depressions between raised ridges; no odontodes on top of ridges (VIEW - B). 22-26 lateral line plates. 50+ teeth per jaw ramus. Pogonopoma (part)
39a. Spinelet of dorsal fin absent or not well developed (visible only as rectangular patch of odontodes; VIEW - C&D). Anus well separated from anal fin spine. Eye bilobed (dorsal flap of iris present; VIEW - A). Odontodes on lateral plates on ridges; ridges not very tall (VIEW - A). 27+ lateral line plates. Fewer than 40 teeth per jaw ramus. 40
     
40a. Nuptial male with hypertrophied odontodes along snout margin (VIEW - B). 5+ rows of plates on the caudal peduncle (VIEW - A). No dorsal-fin spinelet (VIEW - location of dorsal-fin spinelet). Isbrueckerichthys
40b. Nuptial male without hypertrophied odontodes along snout margin (VIEW - A). At least one column of only 3 rows of plates on the caudal peduncle (VIEW - B). Small, rectangular, platelike dorsal-fin spinelet (VIEW - C&D). Neoplecostomus
     
41a. Hypertrophied odontodes present on the snout of nuptial males (VIEW - B). 42
41b. Hypertrophied odontodes absent on the snout of nuptial males (VIEW - A). 44
     
42a. Frontal not forming dorsal rim of orbit. Hypertrophied odontodes present on the lateral plates and caudal-fin spines of nuptial males. White to tan base color with black spots laterally. Small plates present on entire abdomen in adults. Distributed west of the Andes in Ecuador. Hypostomus spinosissimus
42b. Frontal forming dorsal rim of orbit . Hypertrophied odontodes absent on the lateral plates and caudal-fin spines of nuptial males. Brown or gray base color with mottling laterally. Small plates on abdomen either absent or sparsely distributed. Distributed east of the Andes. 43
     
43a. Hypertrophied odontodes on snout present in adult males and usually also females. Hypertrophied odontodes present on cheek that fold into a groove underneath opercle. Pseudancistrus (part)
43b. Hypertrophied odontodes on snout present only in nuptial males. If hypertrophied odontodes present on cheek they are at a right angle to the head and do not fold into a groove underneath opercle (VIEW). Hemipsilichthys (part)
     
44a. Distributed west of the Andes (including the Lago Maracaibo basin). Dark brown ground color. 2+ (usually 3 although two rows may coalesce) rows of plates between suprapreopercle and exposed portion of opercle (VIEW C). Hemiancistrus annectens group (an undescribed genus sister to Pterygoplichthys)
44b. Distributed east and west of the Andes. Dark brown or white to tan ground color (those species to the west of the Andes have a white to tan ground color). 1-2 (usually 1) rows of plates between suprapreopercle and exposed portion of opercle (VIEW A).  Hypostomus
     
45a. Median row of odontodes on each lateral plate forming sharp keels. 46
45b. Median row of odontodes on each lateral plate not forming sharp keels. 47
     
46a. Usually brown with dark spots (one species almost entirely dark brown to gray). Usually only 3 (up to 8) elongated cheek odontodes (present only in adults). 2-3 (usually 3) rows of plates between suprapreopercle and exposed opercle (VIEW - C). Posterior margin of posterior process of cleithrum straight (VIEW - A). Distributed solely west of Andes (including Maracaibo basin, but not the Gulf of Guayaquil drainage or drainages south of the Guayaquil). Stomach usually large. Hemiancistrus annectens group (an undescribed genus sister to Pterygoplichthys)
46b. Dark with white spots or with alternating dark brown and light brown bars. Usually at least 10 elongated cheek odontodes present in juveniles and adults. 1-2 (usually one) rows of plates between suprapreopercle and exposed opercle (VIEW - C). Posterior margin of the posterior process of cleithrum pointed (VIEW - B). Distributed east of Andes. Stomach usually small. Dekeyseria
47a. Fewer than 10 teeth per dentary. Dentaries short, forming acute angle at union 48
47b. More than 10 teeth per dentary. Dentaries long, nearly forming straight line at union. 51
     
48a. Lower lip oval (VIEW - A&B). Body strongly dorsoventrally flattened. 49
48b. Lower lip round (VIEW - C&D). Body deep. 50
     
49a. Dentary teeth very long; crowns consisting of one large and one small lobe, moderately spoon-shaped (VIEW - C). Large adult size >100 mm. Panaque (Scobinancistrus)
49b. Dentary teeth moderately long; crowns consisting of two nearly equally sized lobes, not spoon-shaped. Small adult size <100 mm. Hypancistrus
     
50a. Lower lip fimbriate (VIEW - C). Exastilithoxus
50b. Lower lip not fimbriate (as in VIEW - D). Lithoxus
     
51a. Cheek with about 3-5 very strongly, anteriorly hooked odontodes as well as a few other more nowmal odontodes (VIEW). Nuptial males with sharp odontodes at the corners of the snout. Hopliancistrus
51b. Cheek without stronly, anteriorly hooked odontodes. Nuptial males either without hypertrophied odontodes on the snout, thin hypertrophied odontodes all of the way along the snout, or whiskerlike odontodes at the corners of the snout. 52
     
52a. 4-5 rows of lateral plates on caudal peduncle (VIEW - A). 53
52b. 3 rows of lateral plates on caudal peduncle (VIEW - B). 55
     
53a. Hypertrophied odontodes along edge of snout from evertible odontodes to tip of snout typically present (present on both males and females although much shorter in females; VIEW - B). Fleshy tentacules associated with odontodes along snout margin (VIEW). Usually 4 predorsal plates (count includes nuchal plate). Pseudancistrus (part)
53b. No hypertrophied odontodes along edge of snout from evertible odontodes to tip of snout (VIEW - A). No fleshy tentacules associated with odontodes along snout margin. 3 predorsal plates (count includes nuchal plate). 54
   
54a. Body behind head either entirely dark, or with black or light spots. Hemiancistrus
54b. Body behind head with dorsal saddles (dark spots may be present on abdomen or fins).  Peckoltia
     
55a.  Whiskerlike odontodes anterior to elongated cheek odontodes (VIEW - B). Tentacules on edge of snout of nuptial male longer than associated odontodes (VIEW - D).  Lasiancistrus
55b. No whiskerlike odontodes anterior to elongated cheek odontodes (all cheek odontodes thick). If tentacules present along snout in nuptial male, they are not longer than their associated odontodes (VIEW B-C).  56
56a. No extremely elongated, anteriorly oriented odontodes on snout of nuptial male.  Hypertrophied odontodes along snout margin present in adult males and females.  Pectoral-fin spine reaches anus in adults. Pseudolithoxus
56b. Extremely elongated, anteriorly oriented odontodes on snout of nuptial male (VIEW).  Hypertrophied odontodes along snout margin present only in adult males.  Pectoral-fin spine does not reach anus in adults. Neblinichthys

 
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