Marcelo Britto
Alessandro Gasparetto Bifi (agbifi@gmail.com)
The authors declare no competing interests.
Not applicable.
A new species of
Uma nova espécie de
Loricariidae is the largest family of the Siluriformes in the Neotropics. Loricariidae is widespread in Central and South America, ranging from Costa Rica in the north to Argentina in the south (
Currently, three valid species are recognized from the río Madre de Dios basin:
Posteriorly,
During the expeditions to río Madre de Dios basin in Peru, a new species of
Measurements were taken using digital calipers to the nearest 0.1 mm, and are presented as percents of standard length (SL) or head length (HL). Counts were made under a stereomicroscope. Measurements and plate counts follow
(
Diagnosis.
Description. Morphometric data and counts in
Characters
Lectotype
Paralectotype
N
Range
Mean
SD
Standard length (mm)
51.4
44.8
25
44.8-85.2
62.0
Percents of standard length
Predorsal length
44.5
44.9
25
44.5-49.3
46.8
1.4
Head length
34.4
36.0
25
34.3-39.6
36.8
1.7
Occipital depth
15.4
14.6
25
14.6-17.7
16.4
0.8
Cleithral width
32.6
33.5
25
30.9-35.9
33.5
1.3
Dorsal-fin base length
17.8
18.7
25
17.8-22.4
20.4
1.2
Interdorsal length
20.6
19.1
24
17.6-22.9
20.2
1.3
Prepectoral length
27.2
28.3
25
27.2-32.5
30.1
1.5
Prepelvic length
52.0
54.4
25
49.9-54.4
52.2
1.3
Dorsal-fin spine length
23.0
-
24
19.3-25.4
22.5
1.5
Pectoral-fin spine length
23.4
23.5
25
21.5-26.6
23.9
1.3
First pelvic-fin ray length
25.9
28.5
25
22.8-28.5
25.6
1.4
Adipose-fin spine length
5.6
-
22
3.7-6.3
5.1
0.7
First anal-fin ray length
5.7
8.4
25
5.5-8.7
7.1
0.9
Thoracic length
26.0
29.2
25
23.7-29.2
25.8
1.4
Abdominal length
18.9
18.4
25
16.6-21.3
18.5
1.2
Upper caudal-fin ray length
25.5
-
20
20.7-26.7
23.8
1.6
Lower caudal-fin ray length
31.2
-
22
27.8-33.7
30.2
1.7
Caudal peduncle length
-
-
23
26.8-33.2
29.1
1.3
Caudal peduncle depth
8.7
9.0
25
8.4-10.6
9.5
0.6
Adipose-fin to caudal-fin length
14.6
14.9
24
10.2-14.9
11.9
1.3
Anal-fin to caudal-fin length
32.2
31.8
25
30.8-36.8
33.0
1.5
Percents of head length
Supracleithral width
80.6
78.9
25
73.2-82.1
78.0
2.5
Snout length
63.4
60.7
25
55.1-63.4
58.1
3.0
Interorbital distance
36.4
34.9
25
32.3-40.3
36.0
1.9
Orbital diameter
11.2
11.7
25
8.8-13.0
11.0
0.9
Occipital-orbital distance
38.4
37.9
25
37.9-48.6
41.3
2.6
Dentary width
28.5
31.4
25
21.8-31.4
26.4
2.1
Counts
Lateral median series
24
24
25
24-25
24.5
0.5
Dorsal-fin base
6
6
25
6-7
6.8
0.4
Between dorsal and adipose
7
8
25
7-9
7.6
0.6
Between adipose and caudal
6
6
25
4-6
5.2
0.6
Between anal and caudal
13
13
25
12-14
12.8
0.7
Preadipose plates
4
4
25
4-8
6.2
1.2
Premaxillary teeth
-
-
23
51-96
67.4
11.2
Dentary teeth
86
-
23
55-109
78.9
15.1
Cheek spines
11
8
21
8-19
13.2
2.4
Head moderately large and wide; snout large and rounded in dorsal view, with large naked margin bordered by dermal platelets on lateral portion in males. Adult males with middle- to large-sized tentacles, sometimes branched on dorsal region of snout. Females usually with two small tentacles on each side of snout border. Evertible cheek plates supporting (8-19) hypertrophied odontodes (cheek spines).
Eye small-sized, 8.6-11.9% of HL, dorsal orbit not raised; dorsolaterally positioned. Interorbital region slightly concave. Exposed portion of opercle roughly triangular, supporting odontodes; supra-opercular region with few platelets near compound pterotic.
Oral disk circular covered with small papillae; lower lip large almost reaching pectoral girdle, with papillae reducing in size toward its margin; maxillary barbel short, attached to lip by membrane and with reduced free tip. Branchial opening small. Premaxillary and dentary tooth rows from moderate to large width; teeth short, thin, numerous, unicuspid (
Head covered by dermal bones; dorsum covered by dermal plates, except at dorsal-fin base. Supraoccipital process limited posteriorly by first pair of predorsal plates and posterolaterally by the first plate of the mid-dorsal series. Trunk with five series of lateral plates, three lateral series on the narrowest portion of caudal peduncle. Mid-dorsal and mid-ventral series not surpassing adipose fin. Median series supporting lateral line. Short odontodes on fin rays and body plates. Ventral surface devoid of plates from snout tip to anal-fin insertion. Base of first anal-fin pterygiophore covered by skin.
Dorsal-fin origin situated slightly anterior to vertical through pelvic-fin origin; dorsal fin usually reaching preadipose plate when adpressed; dorsal-fin spine flexible, shorter than head length. Adipose-fin spine short, with small membrane. Pectoral-fin spine inflexible and slightly curved inward, with hypertrophied odontodes and tentacles on distal portion; pectoral fin reaching or slightly surpassing pelvic-fin origin when adpressed. Pelvic fin flexible and curved inward, depressed pelvic-fin unbranched ray surpassing origin of anal fin. Anal fin short. Caudal-fin margin obliquely truncate with ventral unbranched ray longer than dorsal one. Fin-ray formula: dorsal II,7; pectoral I,6; pelvic i,5; anal i,3-4; caudal i,14,i.
Color in alcohol. Body background color yellowish-brown to dark brown. Dorsal surface of head and trunk with rounded light small spots. Ventral surface of head and abdomen yellowish to light brown, brown on ventral surface of caudal peduncle. All fins with alternating dark and light spots on the rays, sometimes organized into transverse bands.
Sexual dimorphism. Largest male and female with 85.2 mm and 74.5 mm SL, respectively. Mature males have small- to middle-sized tentacles on dorsal region and border of snout. Females sometimes with fewer and shorter tentacles than males limited to one series on lateral border of snout, usually two to four on each side of snout. Males have smaller dentary length 21.8-27.1% of HL (mean = 25.0%) than females 26.1-31.4 % of HL (mean= 27.9%).
Geographical distribution.
Conservation status.
Material examined. All from Peru: Lectotype [designated here]: BMNH 1903.10.12.3, female, 51.4 mm SL, syntype of
urn:lsid:zoobank.org:act:ED1397C7-5087-4EB8-94D8-326A42AEEE2D
(
Holotype. MUSM 57733, 114.7 mm SL, male, Peru, Manu District, Manu Province, río Madre de Dios basin, río Salvación, 12º55’05”S 71º27’36”W, 21 May 2006, M. Hidalgo.
Paratypes. Peru: río Madre de Dios basin: INPA 58921, 10, 40.6-101.9 mm SL (2, 68.6-101.9 mm SL), Manu, Parque Nacional del Manu, quebrada Culli, ca. 12º10’S 71º00’W, 5 Sep 1988, H. Ortega
Diagnosis.
Description. Morphometric data and counts in
Characters
Holotype
N
Range
Mean
SD
Standard length (mm)
114.7
21
61.6-147.2
80.9
-
Percents of standard length
Predorsal length
45.7
21
42.9-46.3
44.5
1.0
Head length
35.1
21
32.2-36.2
34.5
1.1
Occipital depth
19.1
21
16.4-19.1
17.6
0.7
Cleithral width
33.8
21
30.4-36.0
32.7
1.3
Dorsal-fin base length
20.3
21
18.4-21.3
19.8
0.9
Interdorsal length
19.9
21
17.9-23.8
20.4
1.6
Prepectoral length
29.2
21
25.8-30.0
28.3
1.1
Prepelvic length
51.5
21
48.9-53.5
50.4
1.1
Dorsal-fin spine length
25.3
21
24.1-27.6
26.0
1.0
Pectoral-fin spine length
29.2
21
25.2-30.5
26.6
1.4
First pelvic-fin ray length
25.9
21
22.6-27.6
25.4
1.2
Adipose-fin spine length
7.2
21
7.2-9.5
8.4
0.7
First anal-fin ray length
9.2
19
7.1-10.8
8.7
0.9
Thoracic length
25.0
21
24.4-27.6
25.9
0.9
Abdominal length
17.9
21
17.5-20.1
18.6
0.7
Upper caudal-fin ray length
26.1
13
24.1-30.3
27.9
1.8
Lower caudal-fin ray length
27.0
14
26.3-35.4
31.2
2.7
Caudal peduncle length
29.3
21
28.7-32.2
30.1
0.9
Caudal peduncle depth
13.1
21
12.2-14.0
12.7
0.4
Adipose-fin to caudal-fin length
13.5
21
13.4-17.7
15.3
1.3
Anal-fin to caudal-fin length
33.8
21
32.0-37.0
35.2
1.2
Percents of head length
Supracleithral width
86.3
21
78.0-92.7
85.1
3.3
Snout length
56.2
21
54.5-60.7
57.2
1.7
Interorbital distance
41.7
21
37.3-41.7
39.3
1.1
Orbital diameter
14.8
21
13.8-20.6
17.8
1.7
Occipital-orbital distance
41.7
21
39.4-43.2
41.4
1.2
Dentary width
26.7
21
25.9-31.4
27.9
1.4
Counts
Lateral median series
24
21
24-25
24.0
0.2
Dorsal-fin base
6
21
6-7
6.1
0.3
Between dorsal and adipose
8
21
6-8
7.2
0.5
Between adipose and caudal
6
21
5-7
5.8
0.5
Between anal and caudal
13
21
12-13
12.6
0.5
Preadipose plates
2
21
2-4
3.2
0.6
Premaxillary teeth
84
20
71-105
83.8
9.1
Dentary teeth
110
20
75-115
94.3
10.7
Cheek spines
26
21
14-26
19.0
3.3
Head moderately large and wide; snout large and rounded in dorsal view, with large naked margin bordered by dermal platelets on lateral portion in males. Adult males with middle- to large-sized tentacles, sometimes branched on dorsal region of snout. Females usually with two small tentacles on each side of snout border. Evertible cheek plates supporting (14-26) hypertrophied odontodes (cheek spines).
Eye mid-sized, 13.8-20.6% of HL, dorsal orbit not raised; dorsolaterally positioned. Interorbital region slightly concave. Exposed portion of opercle roughly triangular, supporting odontodes; supra-opercular region with few platelets near compound pterotic.
Oral disk circular covered with small papillae; lower lip not reaching pectoral girdle, with papillae reducing in size toward margin; maxillary barbel short, attached to lip. Branchial opening small. Premaxillary and dentary tooth rows mid- to large; teeth short, thin, numerous, unicuspid (
Head covered by dermal bones; dorsum covered by dermal plates, except at dorsal-fin base. Supraoccipital process limited posteriorly by first pair of predorsal plates and posterolaterally by the first plate of the mid-dorsal series. Trunk with five series of lateral plates, three lateral series on the narrowest portion of caudal peduncle. Mid-dorsal and mid-ventral series not surpassing adipose fin. Median series supporting lateral line. Short odontodes on fin rays and body plates. Ventral surface devoid of plates from snout tip to anal-fin insertion. Base of first anal-fin pterygiophore covered by skin.
Dorsal-fin origin situated slightly anterior to vertical through pelvic-fin origin; dorsal fin usually reaching preadipose plate when adpressed; dorsal-fin spine flexible, shorter than head length. Adipose-fin spine short. Pectoral-fin spine inflexible and slightly curved inward, with hypertrophied odontodes and tentacles on its distal portion; pectoral fin surpassing pelvic-fin origin when adpressed. Pelvic fin flexible and curved inward, depressed pelvic-fin unbranched ray surpassing origin of anal fin. Anal fin short. Caudal-fin margin obliquely truncate with ventral unbranched ray longer than dorsal one. Fin-ray formula: dorsal II,7; pectoral I,6; pelvic i,5; anal i,4; caudal i,14,i.
Color in alcohol. Body background color yellowish-brown to greenish. Dorsal surface of head and trunk with rounded mid size spots, diameter similar or larger than pupil. Ventral surface of head and abdomen yellowish to light brown, brown on ventral surface of caudal peduncle. All fins with alternating dark and light spots on the rays, sometimes organized into transverse bands.
Sexual dimorphism. Largest male and female with 114.7 mm and 147.2 mm SL, respectively. Mature males have small- to middle-sized tentacles on dorsal region and border of snout. Females sometimes with fewer and shorter tentacles than males limited to one series on lateral border of snout, usually two to four on each side of snout.
Geographical distribution.
Etymology. The specific name
Conservation status.
Eight valid species of
In addition,
The genus has many unsolved taxonomic problems and a complete study is necessary for fully understand this taxon. Similarly, there are few published studies that advance the taxonomic understanding of the loricariids from Peru. Moreover, we suggest that redescription of species poorly known, with improvement of diagnostic characters should be developed for the better comprehension of the taxonomy of
Comparative material examined.
The Instituto Nacional de Pesquisas da Amazônia (INPA) and Museo de Historia Natural, Universidad Nacional Mayor de San Marcos provided logistical and technical support. We are grateful to Adrian Barnett for reviewing the English. AGB is grateful to Anja Palandacic and Ernst Mikschi (NMW), Carlos Lucena and Margarete Lucena (MCP), Guy Duhamel and Aurelie Laurent (MNHN), James Maclaine and Oliver Crimmen (BMNH), Carla Pavanelli and Cláudio Zawadzki (NUP), Richard Vari (
Bifi AG, Ortega H. Redescription of
urn:lsid:zoobank.org:pub:B0B62C38-2D9A-4F59-8310-FE9ABFED0075