RESEARCH ARTICLE
A New Species of Tiger Pleco Panaqolus
(Siluriformes: Loricariidae) from the Xingu
Basin, Brazil
Christian Andreas Cramer1,2*, Leandro Melo de Sousa3
a11111
1 Center for Human Genetics, Faculty of Medicine, Philipps-University Marburg, Marburg, Germany,
2 Laboratório de Ictiologia e Pesca, Departamento de Biologia, Universidade Federal de Rondônia, Porto
Velho, Rondônia, Brazil, 3 Laboratório de Ictiologia, Faculdade de Ciências Biológicas, Universidade
Federal do Pará, Altamira, Pará, Brazil
* Cramerc@gmx.de
Abstract
OPEN ACCESS
Citation: Cramer CA, Melo de Sousa L (2016) A
New Species of Tiger Pleco Panaqolus
(Siluriformes: Loricariidae) from the Xingu Basin,
Brazil. PLoS ONE 11(11): e0165388. doi:10.1371/
journal.pone.0165388
Editor: Michael Schubert, Laboratoire de Biologie
du Développement de Villefranche-sur-Mer,
FRANCE
Received: February 12, 2016
Accepted: October 10, 2016
Published: November 9, 2016
Copyright: © 2016 Cramer, Melo de Sousa. This is
an open access article distributed under the terms
of the Creative Commons Attribution License,
which permits unrestricted use, distribution, and
reproduction in any medium, provided the original
author and source are credited.
Data Availability Statement: DNA sequences will
be available at Genbank from the date of
publication. The Accession numbers are:
KT321857, KT321858, KT321859, KT321860,
KT321861, KT321862, KT321863, KT321864,
KT321865, KT321866, KT321867, KT321868.
Funding: This work was supported by CAC
Conselho Nacional de Desenvolvimento Cientı́fico e
Tecnológico (www.cnpq.br), No. 350674/2010-8,
Three-years-studentship, LMS Conselho Nacional
de Desenvolvimento Cientı́fico e Tecnológico
(www.cnpq.br), No. 486376/2013-3, and
Panaqolus tankei is described from the Xingu River, Brazil. The new species is diagnosed
from P. albomaculatus, P. dentex, P. nix, P. nocturnus, and P. koko by its color pattern consisting of dark and light diagonal bars on the body and bands on the fins (vs. body and fins
without bars or bands); from P. albivermis, P. maccus, and P. purusiensis by the width of
the dark bars being more or less the same of the light bars (vs. dark bars at least two or
three times wider than light bars) and from P. changae by the absence of vermiculation on
the head (vs. vermiculation present on head). The new species differs from P. gnomus by
the orientation of the bars from posterodorsal to anteroventral direction (vs. anterodorsal to
posteroventral direction), and from P. claustellifer by the orientation of the bands in the dorsal fin that are not parallel to the margin (vs. parallel to the margin). The barcoding region
(COI) was sequenced for the new species, sequences were deposited in GenBank and
were compared with congeners from other drainages. With regard to the current construction of a hydroelectric power plant (a so-called mega dam) in the Xingu River, herewith we
increase knowledge of the river Xingu’s ichthyofauna and, thus improve the assessment of
the impacts of that construction on the river.
Introduction
After some debate [1,2,3,4,5,6], Panaqolus Isbrücker & Schraml (2001) is now a well-accepted
genus easily separated from Panaque, the former genus of the Panaqolus-species described
before 2001, by the absence of a ventrolateral keel on the caudal peduncle (vs. present) and postero-dorsal margin of the supraoccipital plate pointed (vs. margin straight). Currently, eleven
species are recognized: Panaqolus albivermis Lujan, Steele & Velasquez, 2013; P. albomaculatus
(Kanazawa, 1958), P. changae (Chockley & Armbruster, 2002), P. claustellifer (Tan, Souza &
Armbruster, 2016), P. dentex (Günther, 1868), P. gnomus (Schaefer & Stewart, 1993), P. koko
Fisch-Muller & Covain, 2012, P. maccus (Schaefer & Stewart, 1993), P. nix Cramer & Rapp Py-
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New Panaqolus from Xingu River
Research-grant for fieldwork at the Xingu River,
Fieldwork supported in part by NSF DEB-1257813
(CoPI Mark Sabaj Pérez).
Competing Interests: The authors have declared
that no competing interests exist.
Daniel, 2015, P. nocturnus (Schaefer & Stewart, 1993), and P. purusiensis (Lamonte, 1935). The
diversity of the genus is, however, nowhere near fully described. There are at least 10 undescribed species known in the aquarium trade from the main drainages of the Amazon, including Río Ucayali, Rio Negro, Rio Madeira, Rio Tapajós, Rio Curuá-Una, Rio Paru and Rio
Xingu, amongst others. These species are still awaiting formal description, mainly due to a lack
of specimens deposited in scientific collections.
The Rio Xingu, the fourth largest drainage on the Amazon, has an astonishing diversity of
loricariids with at least 60 species from more than 25 genera occurring in its Lower and Middle
courses, of which 18 species are endemic and 15 are still undescribed (LMS, pers. obs.; [7]).
At the time of writing, a huge hydroelectric power plant is under construction in the middle
reaches of the Rio Xingu, with yet unknown consequences for the often highly specialized local
fish fauna. Thus, the aim of the present study is to contribute to the effort of improving our
knowledge of these endemic fishes by describing a new species of Panaqolus from the Lower
Xingu River.
Methods
Morphological analysis
Counts, measurements and terminology follow Lujan et al. [8]. All measurements were made
to the nearest 0.1 mm with the use of digital calipers. The following abbreviations were used:
SL, standard length; HL, head length; and c&s, cleared and stained. For clearing and double
staining we followed the protocol from Tayler & van Dyke [9]. Institutional abbreviations are
as listed in Sabaj Pérez [10]. Specimens were collected with LMS’ IBAMA permit #31089–1
which is valid in the whole Brazilian territory. Collected fish were first euthanized using clove
oil and then fixed in formalin, following the guidelines of the Brazilian Society of Ichthyology
[11]. No endangered species were collected. Only fixed museum material was used for the present work, therefore, according to the Brazilian legislation, no approval by an ethics committee
was necessary.
The type specimens were publicly deposited in the permanent collections of the following
institutions: INPA, Instituto Nacional de Pesquisas da Amazônia, Manaus/AM, Brazil; USNM,
Smithsonian Institution National Museum of Natural History, Washington, D.C., United
States of America (USA); MNRJ, Museu Nacional da Universidade Federal do Rio de Janeiro,
Rio de Janeiro/RJ, Brazil; MPEG, Museu Paraense Emílio Goeldi, Belém/PA, Brazil; ANSP,
Academy of Natural Sciences of Drexel University, Philadelphia, USA; MZUSP, Museu de
Zoologia da Universidade de São Paulo, São Paulo/SP, Brazil.
DNA sequencing, editing, and alignment
Total DNA was extracted from ethanol-preserved fin samples using DNeasy Tissue Kit (Qiagen), following manufacturer’s instructions. Partial sequences of Cytochrome c Oxidase subunit 1 [12] were amplified and sequenced using the protocol and the primers from Roxo et al.
[13]. The DNA sequences were edited and aligned using BioEdit 7.0.9 [14]. Nucleotide variation was examined using MEGA 6.0 [15].
Nomenclatural Acts
The electronic edition of this article conforms to the requirements of the amended International Code of Zoological Nomenclature, and hence the new names contained herein are available under that Code from the electronic edition of this article. This published work and the
nomenclatural acts it contains have been registered in ZooBank, the online registration system
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New Panaqolus from Xingu River
for the ICZN. The ZooBank LSIDs (Life Science Identifiers) can be resolved and the associated
information viewed through any standard web browser by appending the LSID to the prefix
“http://zoobank.org/”. The LSID for this publication is: urn:lsid:zoobank.org:pub:F416B09C018D-441F-88F5-9284A1330EF9. The electronic edition of this work was published in a journal with an ISSN and has been archived and is available from the following digital repositories:
PubMed Central, LOCKSS.
Results
Panaqolus tankei, new species. urn:lsid:zoobank.org:act:EA10AD3E-BD02-402F-9317D297048B974B (Fig 1)
Panaqolus sp. L398: Werner [16]: 56 (Figs 1–3)
Holotype
INPA 41135, 72.8 mm SL, Brazil, Pará, rio Xingu, 17 km south from Senador José Porfírio,
main channel, (02°44’54.7”S 52°00’09.5”W), 13 Jul. 2012, L. M. Sousa et al.
Paratypes
101 specimens. All Brazil: Pará: USNM 376497, 2, 41.6–50.2 mm SL, 72.5 km below Senador
Jose Porfirio, 31.5 km above Porto de Moz (02°01’59.16”S 52°14’53.88”W), 09 Nov. 1994, L. H.
Rapp Py-Daniel et al. INPA 31777, 29 (1 c&s), 26.7–82.8 mm SL, Vitória do Xingu (02°51'36"S
51°59'20"W), 04 Nov. 2008, Rapp Py-Daniel et al. MZUSP 115040, 5, 36.8–63.3 mm SL, same
data as INPA 31777. MNRJ 41741, 7, 33.2–56.5 mm SL, same data as holotype. ANSP 195074,
4, 33.1–78.9 mm SL, rio Xingu, municipality of José Porfírio (02°44’54,7” S 52°0’9,5”W), 13 Jul.
2012, Sousa et al. MPEG 28832, 3, 40.6–66.9 mm SL, same data as ANSP 195074. INPA 40506,
8, 25.7–69.1 mm SL, rio Xingu, deep channel along right bank of river ca. 38 km southeast of
Vitória do Xingu (3°5’32.39”S 51°44’14.1”W), 21 Sep. 2013, Sabaj-Pérez et al. INPA 40536, 8,
45.5–78.4 mm SL, rio Xingu, along left bank of river ca. 8 km east of Vitória do Xingu (2°
53’18.7”S 51°56’24.54”W), 22 Sep. 2013, Sabaj-Pérez et al. INPA 40562, 17, 23.3–40.0 mm SL,
rio Xingu, main channel off downstream point of large island, ca. 13.5 km east-southeast of
Vitória do Xingu (2°55’16.39”S 51°53’41.6”W), 22 Sep. 2013, Sabaj-Pérez et al. INPA 40567, 6,
32.2–74.9 mm SL, rio Xingu, main channel off upstream point of large island, ca. 2.5 km northeast of mouth of igarapé leading to Vitória do Xingu. (2°51’34.2”S 51°58’46.14”W), 22
Sep. 2013, Sabaj-Pérez et al. INPA 40644, 12, 29.5–83.0 mm SL, rio Xingu, main channel along
left bank, ca. 10 km southwest and across river from Senador José Porfírio (2°38’51.5”S 52°
1’39”W), 24 Sep. 2013, Sabaj-Pérez et al.
Diagnosis
Panaqolus tankei can be differentiated from all congeners except P. albivermis, P. changae, P.
claustellifer, P. gnomus, P. maccus and P. purusiensis by the presence of dark bars on the trunk
and bands on the fins alternating with light interspacing (vs. body and fins without bars or
bands). It differs from P. albivermis, P. maccus, and P. purusiensis by the width of the dark bars,
which is more or less the same width of the light bars (vs. dark bars at least two or three times
wider than light bars) and from P. changae by the absence of vermiculation on the head (vs. vermiculation present on head). The new species differs from P. claustellifer by by the number of
dorsal-fin bands (2–4 vs. 2) and their orientation being not parallel to the margin of the fin (vs.
parallel to the margin), and from P. gnomus by the orientation of the bars on the body from posterodorsal to anteroventral direction (vs. anterodorsal to posteroventral direction). Panaqolus
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New Panaqolus from Xingu River
Fig 1. Holotype of Panaqolus tankei n. sp. INPA 41135, 72.8 mm SL, Brazil, Pará, rio Xingu, 17 km south from Senador
José Porfı́rio (02˚44’54.7”S 52˚00’09.5”W).
doi:10.1371/journal.pone.0165388.g001
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New Panaqolus from Xingu River
Fig 2. Live photos of all described species of Panaqolus. (photo credits: A. Tanke [a, b, c, l], R. Heidemann [d], I. Seidel [e, h], J. Dignall [f], J.
Gottwald [g], H.-G. Evers [i], E. Bertelsen [j], and C. Cramer [k]).
doi:10.1371/journal.pone.0165388.g002
Fig 3. Ventral view of mouth of Panaqolus tankei. (a) oral disk, (b) details of premaxillary teeth and (c)
dentary teeth (photos by R. Heidemann; live aquarium specimen; ca. 85 mm SL).
doi:10.1371/journal.pone.0165388.g003
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New Panaqolus from Xingu River
tankei can be further differentiated from P. albivermis by a greater cleithral width (32.2–37.0%
SL vs. 29.7–32.4%), a longer head-pectoral length (25.7–32.5% SL vs. 23.1–25.2% SL), and a
lower caudal peduncle depth (10.0–12.3% SL vs. 12.2–14.9% SL); from P. changae by the snout
having more or less straight lines (vs. vermiculated lines in the snout) and five to seven dark
bars on the trunk (vs. 6–12), the first three bars in phase of splitting, forming a D shape, or are
already completely split in adults (vs. relatively thin and compact lines); and from P. maccus by
the presence of alternating dark and light stripes on the head coloration (vs. light stripes frequently broken into dots, often forming a vermiculated pattern and not leading straight to the
margin of the head). Live photos of all described species of Panaqolus are in Fig 2.
Description
Proportional measurements in Table 1. Medium to small-sized loricariid with standard length
of measured specimens up to 83.0 mm SL. Dorsal profile of head and snout strongly convex
from snout tip to posterior tip of supraoccipital, straight and posteroventrally slanted between
dorsal-fin origin and adipose-fin origin, gently concave through caudal peduncle to posterior
tip of last procurrent caudal fin ray. Dorsal orbit margin slightly raised, forming a small ridge,
narrowing anteriorly, from anterior orbit margin to area lateral to nares. Dorsal surface of
trunk transversely flattened from dorsal-fin origin to adipose-fin base. Ventral profile of head
and body flat from oral disk to anal-fin origin. Caudal peduncle oval in cross-section and moderately deep (10–12% SL).
Greatest body depth at dorsal-fin origin. Pectoral-fin origin just posterior to orbit, pelvic-fin
origin at vertical through origin of second dorsal-fin ray, anal-fin origin shortly posterior after
vertical through origin of last dorsal-fin ray. Adipose fin with well-ossified leading spine bearing odontodes.
Dorsal fin II,7, pectoral fin I,6, pelvic fin I,5, anal fin I,3–4 (mode 4), caudal fin I,14–15,I
(mode 14 branched rays). Spinelet triangular, dorsal-fin spine lock functional, posterior fin
margin straight, margin of last two rays rounded. Dorsal fin origin closer to vertical line passing through pelvic-fin origin than to vertical line passing through pectoral fin origin; not
reaching adipose fin when adpressed. Adipose fin triangular; adipose-fin spine slanted posteroventrally, tip straight to curved ventrally, pointed; posterior margin of adipose-fin membrane
concave to nearly vertical. Pectoral-fin spine robust, posterior fin margin straight, when
adpressed reaching 1/3 of pelvic fin. Pelvic-fin spine robust, posterior margin slightly
rounded, when adpressed reaching mid-length of anal-fin spine. Caudal fin forked with short
filamentous extensions on rays.
Head and body entirely plated except for small naked area along dorsal-fin base, snout without naked area near tip. Abdomen of adults mainly naked, only triangle formed by the anus
and the two pelvic-fin origins covered by small plates. Abdomen of juveniles not plated. Area
dorsal to pelvic-fin base below ventral margin of inframedian plate row usually naked.
Supraoccipital bordered posteriorly by 2 scutes on each side. Body with pronounced lateral
ridge extending from cleithrum to posterior margin of fifth or sixth plate of the inframedian
plate row; ridge gradually decreasing in prominence posteriorly. Trunk without elevated ridges.
6–7 (mode 7) scutes on dorsal-fin base, 5–6 (mode 6) scutes between dorsal and adipose fin,
5–7 (mode 6) scutes between adipose and caudal fin, 2 scutes on anal-fin base, 9–12 (mode 10)
scutes between anal and caudal fin, 22–25 (mode 24) scutes on lateral line. 28 vertebrae including 5 in the Weberian apparatus and 1 the ural centra.
Head and body covered by odontodes of uniform size and distribution. Enlarged odontodes
on anterodorsal border of pectoral-fin spine. Cheek odontodes hypertrophied with tips
recurved distally, longest odontode extending to posterior cleithrum margin. Interorbital space
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New Panaqolus from Xingu River
Table 1. Selected morphometric features of Panaqolus tankei. Values are given as percent of standard length or head length. SD = standard deviation,
n = number of specimens, H = holotype. Interlandmarks (ILM) are the two points between which measurements were taken (from [8]).
Panaqolus tankei
ILM
Measurement
1–20
Standard length
H
n
72.8
range
101
23.3–83.0
mean±SD
51.3
Percent of Standard Length
1–10
Predorsal length
48.5
83
42.5–51.1
46.3±1.6
1–7
Head length
39.2
84
31.6–45.4
38.9±1.9
8–9
Cleithral width
34.3
84
32.2–37.0
34.1±0.9
8’–9’
Cleithral width ventral
33.4
83
30.3–36.3
33.0±1.0
1–12
Head–pectoral length
26.3
83
25.7–32.5
28.4±1.4
12–13
Thorax length
27.3
84
23.0–32.1
27.0±1.6
12–29
Pectoral-spine length
34.0
84
26.3–36.5
33.0±1.6
13–14
Abdominal length
26.0
84
19.7–26.0
23.2±1.1
13–30
Pelvic-spine length
27.9
84
25.9–32.9
29.1±1.4
13–13’
Pelvic girdle width
23.8
84
19.1–24.2
22.0±0.8
14–15
Postanal length
31.2
84
23.6–34.6
31.1±1.7
14–31
Anal-fin spine length
16.9
81
10.3–19.2
14.9±1.5
10–12
Dorsal–pectoral depth
32.6
83
28.7–33.4
30.8±1.0
10–11
Dorsal-spine length
32.3
68
26.7–35.2
32.1±1.7
10–13
Dorsal–pelvic depth
26.6
82
18.6–28.0
24.8±2.0
10–16
Dorsal-fin base length
26.9
81
21.0–30.9
25.9±1.4
16–17
Dorsal–adipose distance
16.4
83
13.7–20.4
16.7±1.2
17–18
Adipose-spine length
8.5
83
5.8–11.4
8.6±0.9
17–19
Adipose–upper caudal distance
14.3
83
12.8–18.0
14.9±1.1
11.1±0.5
15–19
Caudal peduncle depth
11.2
83
10.0–12.3
20–32
Caudal peduncle–middle caudal ray
21.1
82
16.9–24.9
21.2±1.8
20–33
Caudal peduncle–dorsal caudal spine
32.0
12
32.0–44.8
38.0±4.4
15–17
Adipose–lower caudal depth
22.4
83
20.7–25.9
23.2±1.1
14–17
Adipose–anal depth
19.3
82
15.3–20.4
18.3±1.0
5–7
Head–eye length
36.5
83
28.6–45.0
35.5±2.2
4–5
Orbit diameter
18.9
83
15.8–25.2
19.1±1.2
Percent of Head Length
1–4
Snout length
59.2
83
50.9–71.6
59.2±2.8
2–3
Internares width
11.0
83
9.6–15.7
12.1±1.1
5–6
Interorbital width
51.0
83
41.4–62.9
49.7±2.9
5’–6’
Dorsal interorbital width
34.1
83
30.3–45.5
35.4±2.1
7–12
Head depth
70.3
83
58.1–80.0
68.1±3.8
1–24
Oral-disk length
44.3
83
38.1–55.9
45.1±2.5
21–22
Oral-disk width
41.1
83
35.4–49.2
41.5±2.5
22–23
Barbel length
10.1
83
7.1–16.9
11.9±2.0
doi:10.1371/journal.pone.0165388.t001
straight or slightly convex. Eye moderately large, dorsolaterally placed; orbit diameter 15.8–
25.2% HL. Iris diverticulum present. Nares small and ovoid, slightly longer than wide.
Oral disk more or less circular, distal margin of upper lip well separated from maxillary barbel base (Fig 3a). Maxillary barbels of moderate length (7–17% HL), tip of barbel sometimes bior trifurcated. Lips moderately rugose, small patch of elongate fleshy papillae medial to each
tooth row. Border of lips smooth.
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New Panaqolus from Xingu River
Teeth spoon-shaped with small lateral cusp. Premaxillary teeth 4–7 per ramus (mode 6),
mandibular teeth 4–9 per ramus (mode 7). In contrast to Panaque [8], no correlation of SL and
number of teeth was found. Premaxillae tooth rows angled at approximately 80°, dentary tooth
rows at approximately 60° (Fig 3).
Color in alcohol
Ground coloration yellowish white. Fins showing dark bands on light ground in all body sizes:
2–4 in dorsal fin, 2–5 in pectoral fin, 2–4 in ventral fin, 1–2 in anal fin, 2–5 in caudal fin and
1–2 in adipose fin (mode 2). Number of bands on fins increasing with body size. Small individuals have 5 compact bands (Figs 4 and 5a). In larger individuals, the first three dark bands on
the body in phase of splitting, forming a D (Fig 5b), the second and third band sometimes
completely split, resulting in two separate thin bands. Fourth and fifth bands sometimes in
form of an inverted Y shape (Fig 5c and 5d). Head with dark lines going from supraoccipital to
anterior margin of snout. 3–4 (mode 3) lines under the eye, often being split at the ventral margin of the head, forming an inverted Y shape. One dark line between eye and nare and 2
between the nares. These lines may be partially split, forming an inverted Y, an elongated 0 or a
sequence of 0s (see Fig 6). Dark lines on head usually thicker than light interspaces. Belly uniformly yellowish white or with light brown dots or vermiculations. Oral disk yellowish white.
Live coloration is shown in Figs 4 and 7.
Sexual dimorphism
Mature males strongly display elongated odontodes on the caudal peduncle, whereas females
and juveniles only have short odontodes.
Distribution and habitat
The species is only known from the lower Xingu River, downstream Belo Monte Waterfalls
(Fig 8). Panaqolus tankei are usually found on fallen trees and sunken wood alongside the riverbank, in depths varying from 1 to 10 m (Figs 9 and 10).
Etymology
A patronym in honor of Andreas Tanke, a German aquarist very dedicated to the genus Panaqolus, studying its behavior, reproduction, and differences between known forms, keeping
these fishes in the aquarium, visiting their habitats, and publishing his findings (e.g.[17]). He
probably was the first to reproduce Panaqolus tankei in captivity [18]. For his (successful)
efforts to improve communications between aquarists and scientists to join their forces in an
era of less and less money for research and an ever accelerating destruction of natural habitats.
Molecular Analyses
Six hundred sixty-seven (667) basepairs of the Cytochrome c Oxidase subunit 1 (COI), the so
called barcode region [12], have been amplified for 12 specimens (localities, collection numbers
and GenBank accession numbers in Table 2). Seven of them are P. tankei; the other five specimens belong to a putative new species from Rio Tocantins (from locations close to the cities
Cametá and Portel). As only few specimens from that probable new species are available in scientific collections, analyses on its taxonomic status have not been possible. However, differences in the coloration compared to described species indicate that they might represent a new
species. GenBank sequences from P. changae (EU359435.1) and P. albivermis (EU359436.1),
the only congeners of which sequences were available, were used for comparison. The
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New Panaqolus from Xingu River
Fig 4. Juvenile Panaqolus tankei. Estimated standard lengths: (a) 14.5 mm, (b) 19.8 mm, (c) 21.4 mm,
and (d) 30.0 mm (photos by I. Seidel).
doi:10.1371/journal.pone.0165388.g004
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Fig 5. Variation in the body coloration of Panaqolus tankei. a) small specimen with five compact bands (ANSP 195074, 43.5 mm SL);
b) adult specimen with the 1st and 2nd bands in phase of splitting, forming a D; the 3rd band is already split into two thin bands (ANSP
195074, 78.9 mm SL); c) adult specimen with the 2nd band nearly and 3rd band completely split, the 4th band forming an inverted Y (ANSP
195074, 73.2 mm SL); d) adult specimen with the 2nd and 3rd bands completely split (INPA 40644, 65.0 mm SL).
doi:10.1371/journal.pone.0165388.g005
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New Panaqolus from Xingu River
Fig 6. Variation of the head coloration of Panaqolus tankei. a) compact straight lines b) partially split
lines, forming an inverted Y, an elongated 0 or a sequence of 0s (both INPA 31777).
doi:10.1371/journal.pone.0165388.g006
intraspecific variability was 0% to 1.1% for P. tankei, and 0.2% to 0.5% for the putative new species from the Rio Tocantins. Interspecific variability was 0.3% to 1.7% for P. tankei-Panaqolus
sp. Tocantins, 0.8 to 1.8% for P. tankei-P. changae, and 4.1% to 4.6% for P. tankei-P. albivermis.
Further distances were 0.8% to 1.1% for Panaqolus sp. Tocantins -P. changae, 4.1% to 4.5% for
Panaqolus sp. Tocantins -P. albivermis, and 4.0% for P. changae-P. albivermis. The intraspecific
variation in P. tankei was higher than the distances between P. tankei and the putative new species. Similar results were found in the loricariid genus Rineloricaria[19]. Identification via
DNA barcodes is based on the observation that intraspecific genetic divergence is usually lower
than interspecific divergence, leading to the so called ‘barcoding gap’[20]. At first, DNA barcoding studies suggested that a 2% threshold typically represented a cut-off between species
[12], but later it was showed that the divergence between species can fall well below this value,
depending on the taxa of interest [21,22]. To be able to characterize species with very low interspecific variability, a character bases approach was successfully tested [23,24]. This approach is
comparable to the traditional morphology-based methods where a species diagnosis would be
based on a binary signal—the presence or absence of a diagnostic character (in this case a DNA
character), therefore bypassing the uncertainty found in an analogue measurement of sequence
similarity. These diagnostic sites of interest are referred to as nucleotide diagnostics (ND) [24].
Such a ND was found for P. tankei in position 351 (T vs. A in all other analyzed species).
Another ND was found for Panaqolus sp. Tocantins on position 198 (C vs. T in all other analyzed species).
An exhaustive comparison of the barcode region of all described species of Panaqolus was
not possible due to difficulties in getting tissue samples. Many species occur in remote regions
and are rarely caught by scientists.
Discussion
Together with P. changae, P. claustellifer and P. purusiensis, P. tankei is part of a group of very
similar species that differ mainly in details of their coloration (e.g. wormlines on the head vs.
straight lines; number and width of the dark bars on the body). The forms most akin to P. tankei are a putative new species distributed in the Rio Negro basin [25] and P. claustellifer. Unfortunately, no fixed material of the former is available for comparison. Preliminary results from
an analysis of DNA sequences from five genes show these (putative) species to be clearly distinct (Lujan (Royal Ontario Museum), personal communication). Furthermore, adult P. tankei
have 3 to 4 dark bands in the dorsal fin which are orientated non-parallel to the margin of the
fin, whereas P. claustellifer has only two bands and these are parallel to the margin of the fin
[26]. Barcode sequences [12] from seven P. tankei and five specimens of Panaqolus sp. from rio
PLOS ONE | DOI:10.1371/journal.pone.0165388 November 9, 2016
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New Panaqolus from Xingu River
Fig 7. Live coloration of Panaqolus tankei. (a) from the region of Vitória do Xingu (live aquarium specimen; photo by R. Heidemann) and
(b) from the region of Porto de Moz with more and finer lines on the head (live aquarium specimen; photo by A. Tanke).
doi:10.1371/journal.pone.0165388.g007
Tocantins were very similar, with very low interspecific variation. Similar color patterns have
been found for a broad variety of loricariids from the Rios Xingu and Tapajós [27]. Low genetic
distances between congeners have already been reported for other members of the subfamily
Hypostominae [4,19,28,29]. This pattern can also be found in other diverse groups like piranhas (Serrasalmus & Pygocentrus) [30]. This supports the theory of recent radiation of the Neotropical fish fauna [28,30].
PLOS ONE | DOI:10.1371/journal.pone.0165388 November 9, 2016
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New Panaqolus from Xingu River
Fig 8. Distribution map of Panaqolus tankei. Solid symbol: type locality. Symbols may represent more
than one locality or lot. Inset rectangle indicates location of study area in South America.
doi:10.1371/journal.pone.0165388.g008
Nucleotide diagnostics suggest that all specimens from the Rio Tocantins represent a single
lineage, distinct from P. tankei. One ND could be found for each P. tankei and the new species
from Rio Tocantins. Also of interest is the greater distance of all broad banded species from P.
albivermis, a species with thin bands and/or dots, showing that the coloration is a strong character for differentiation in this genus. Costa-Silva et al. [19] proposed that recognition as a formal new species is justified even if only morphological traits or high molecular divergence
distinguish a population from others.
From the region of Porto de Moz, near mouth of the Xingu, a population of Panaqolus is
known which has slightly more and finer lines on the snout (A. Tanke (Neustadt am Rübenberge), personal communication; Fig 7) than P. tankei from the middle reaches of the Xingu
river. As no material for comparison has been available, we cannot state here if it is a variant of
P. tankei or a distinct species. Other similar populations which potentially represent distinct
and undescribed species have been reported from the rivers Tocantins[31], Jari, Curuá-Una,
Tapajós [32], Anapu [33], and Rio do Pará [34]. A molecular analysis is in preparation to give
us further insights into the relationships between the species and populations of the genus.
Many species of Panaqolus are common in the aquarium trade and P. tankei has been introduced to fishkeeping hobbyists as L398 [16]. Although being an endemic species from Xingu,
the geographic distribution of P. tankei does not directly overlap the impacted area of the
recently implemented Belo Monte Dam. The habit of living and feeding on sunken wood in
lowland riverbanks will likely remain unharmed in most parts of its distribution. However,
hobbyist observations in the aquarium show that spawning of these fish appears to depend on
seasonal changes in the water quality and temperature [18] and these water parameters should
be constantly monitored to guarantee the natural cycles downstream the impacted area.
PLOS ONE | DOI:10.1371/journal.pone.0165388 November 9, 2016
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New Panaqolus from Xingu River
Fig 9. Typical habitat of Panaqolus tankei. Riverbank in Lower Xingu.
doi:10.1371/journal.pone.0165388.g009
Comparative material
Panaqolus albomaculatus: Ecuador: USNM 167909, holotype, 91.1 mm SL, río Pucuno, tributary of Suno (altitude 350–400 m). USNM 167910, paratype, 81.7 mm SL, río Cotapino, tributary of río Pucuno. USNM 167908, paratypes, 4, 48.5–78.5 mm SL, Pastaza, río Bobonaza,
Pastaza drainage. Peru: Amazonas: AUM 45502, 5, 39.6–103.7 mm SL, río Marañón, log riffle,
1.57 km ENE of Juan Valesco (Sta. Maria de Nieva). AUM 45507, 5, 79.1–114.8 mm SL, río
Marañón, log riffle, 1.57 km ENE of Juan Valesco (Sta. Maria de Nieva). LACM 36357–33, 72.3
mm SL, río Cenepa, vicinity of Huampami. LACM 42001–9, 2, 91.4–113.3 mm SL, 100 m
downstream from Caterpiza. LACM 41740–18, 99.8 mm SL, río Marañón at confluence with
río Nieva at Sta. Maria de Nieva. LACM 36330–5, 120.2 mm SL, Caterpiza, quebrada. LACM
42005–10, 94.6 mm SL, 1 km upstream from Caterpiza. LACM 36313–3, 2, 84.9–96.1 mm SL,
río La Poza. LACM 42115–6, 54.8 mm SL, Caterpiza. UFRO-I 17825, 77.5 mm SL, aquarium
specimen. Panaqolus changae: Peru: Loreto: MUSM 17107, holotype, 58.8 mm SL, río Itaya,
11km SSW center of Iquitos at bearing 39°. SIU 29928, paratype, 45.2 mm SL, río Itaya, 11km
SSW center of Iquitos at bearing 39°. INHS 42419, paratypes, 2, 38.5–83.0 mm SL, río Itaya,
11km SSW center of Iquitos at bearing 39°. AUM 28908, 5, 53.0–84.5 mm SL, río Momon, ca.
8 hours by boat from Iquitos. Panaqolus dentex: Peru: Loreto: BMNH1867.6.13.37, holotype,
58.8 mm SL, rio Xeberos, Huallaga drainage. Amazonas: FMNH 96952, 73.8 mm SL, Caterpiza.
PLOS ONE | DOI:10.1371/journal.pone.0165388 November 9, 2016
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New Panaqolus from Xingu River
Fig 10. Underwater picture of the natural habitat of Panaqolus tankei.
doi:10.1371/journal.pone.0165388.g010
Table 2. Locality, collection numbers, and GenBank accession numbers of the voucher specimens and the COI sequences.
Species
Tissue tag Collection
number
Locality
GenBank accession
number
Panaqolus tankei
1132
Rio Xingu, ca. 2.5 km northeast of mouth of igarapé leading to
Vitória do Xingu
KT321857
INPA 40567
Panaqolus tankei
1038
INPA 40506
Rio Xingu, ca. 38 km southeast of Vitória do Xingu
KT321858
Panaqolus tankei
1149
INPA 40562
Rio Xingu, ca. 13.5 km east-southeast of Vitória do Xingu
KT321859
Panaqolus tankei
1150
INPA 40562
Rio Xingu, ca. 13.5 km east-southeast of Vitória do Xingu
KT321860
Panaqolus tankei
1262
INPA 40644
Rio Xingu, ca. 38 km southeast of Vitória do Xingu
KT321861
Panaqolus tankei
1263
INPA40644
Rio Xingu, ca. 38 km southeast of Vitória do Xingu
KT321862
Panaqolus tankei
598
uncatalogued
Rio Xingu, Ca. 15 km downstream from Vitória do Xingu, right
margin
KT321863
Panaqolus sp.
Tocantins
P2796
MPEG31592
Rio Tocantins, 11 km upstream from Cametá
KT321864
Panaqolus sp.
Tocantins
P2797
MPEG31592
Rio Tocantins, 11 km upstream from Cametá
KT321865
Panaqolus sp.
Tocantins
P2807
MPEG31592
Rio Tocantins, 11 km upstream from Cametá
KT321866
Panaqolus sp.
Tocantins
P3075
MPEG31594
Rio Camarapi, 11 km upstream from Portel, rio Tocantins drainage
KT321867
Panaqolus sp.
Tocantins
P3079
MPEG31594
Rio Camarapi, 11 km upstream from Portel, rio Tocantins drainage
KT321868
doi:10.1371/journal.pone.0165388.t002
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New Panaqolus from Xingu River
LACM 39892–1, 3, 46.9–67.7 mm SL, Shaime, village on río Yutupis, from small quebrada.
LACM 41993–6, 2, 66.9–68.3 mm SL, 3 km upstream from Caterpiza. LACM 41995–3, 71.1
mm SL, 3 km upstream from Caterpiza—Kusuim. LACM 36329–6, 41.4 mm SL, Caterpiza,
quebrada. LACM 41946–1, 38.3 mm SL, 200 m upstream from Caterpiza. LACM 39952–1, 4,
43.6–72.9 mm SL, Small Quebrada in Galilea, tributary to río Santiago. AMNH 218002, 76.7
mm SL, río Santiago. Ecuador: Napo: FMNH 97595, 2, 67.6–73.5 mm SL, Quebrada Apoalla,
tributary to lower río Shushufindi, Napo drainage. FMNH 97596, 2, 74.1–78.4 mm SL, lower
río Bobonaza at Chicherota, about 25 km upstream from mouth of río Pastaza. FMNH 97593,
41.4 mm SL, Estero Samonayacu, about 3.5 km SW of the bridge over río Napo along road
from Coca to río Tiputini. Panaqolus gnomus: Ecuador: Pastaza: FMNH 70860, holotype, 56.5
mm SL, Cusuimi, on río Cusuimi, about 150 km SE of Puyo. FMNH 97598, paratypes, 2, 56.0–
56.1 mm SL, río Bobonaza at Sarayacu, Pastaza drainage. FMNH 97597, paratypes, 3, 53.0–
55.7 mm SL, Cusuimi, on río Cusuimi, about 150 km SE of Puyo. Orellana: USNM 163912,
paratype, 60.9 mm SL, río Suno, upper Napo drainage. Peru: Amazonas: FMNH 96950, paratype, 69.2 mm SL, río Cenepa, vicinity of Huampami, elevation 700 m. LACM 42005–11, paratype, 62.0 mm SL, 1 km upstream from Caterpiza. LACM 42115–7, paratypes, 2, 59.9–67.7
mm SL, Caterpiza. LACM 41992–6, paratypes, 2, 59.3–63.6 mm SL, 500 m upstream from
Caterpiza. LACM 36330–4, paratypes, 2, 59.8–63.2 mm SL, Caterpiza, quebrada. AUM 45505,
5, 51.0–64.3 mm SL, río Marañón, log riffle, 1.57 km ENE of Juan Valesco (Sta. Maria de
Nieva). AUM 45501, 10, 47.0–68.3 mm SL, same data as AUM45505. Panaqolus koko: French
Guyana: SMF 9702, 84.7 mm SL, Saint Laurent du Maroni: Maroni River, Saut Ga-kaba to
Apatou. Panaqolus maccus: Venezuela: MCBUCV-V 24010, holotype, 66.0 mm SL, Portuguesa, río Las Marinas, upstream from bridge on Route 5 east of Cuanare, tributary of río Portugesa. FMNH 97603, paratypes, 3, 29.0–49.8 mm SL, same data as holotype. FMNH 105998,
3, 31.8–52.2 mm SL, Barinas, río Anaro, ca. 10 minutes from mouth in río Suripa, río Apuré
drainage. USNM 265675, 31.6 mm SL, Bolivar, río Orinoco, Cove, Tslote de Fajardo, 182 nautic
miles upstream from Sea Buoy. Panaqolus nix: Brazil: Rondônia: INPA 39606, holotype,
110.1 mm SL, rio Madeira, cofferdam at construction site of Santo Antonio hydroelectric
power plant (former Santo Antonio rapids). UFRO-I 6384, 5, 50.8–80.7 mm SL, rio Marmoré,
near comunity São Lourenço. UFRO-I 7968, 1, 81.4 mm SL, rio Madeira, near Ilha do Búfalo.
UFRO-I 9974, 1, 53.6 mm SL, rio Madeira, below Santo Antonio rapids. UFRO-I 10050, 1, 90.4
mm SL, same data as UFRO-I 6384. UFRO-I 13039, 1, 49.5 mm SL, same location as holotype.
UFRO-I 13040, 1, 57.7 mm SL, same data as UFRO-I 13039. UFRO-I 19646, 1, 97.3 mm SL,
same data as holotype. INPA 39605, 3, 54.6–73.7 mm SL, same data as UFRO-I 6384. MZUSP
114009, 3, 68.5–76.2 mm SL, same data as UFRO-I 6384. Uncat., 2, 95.3–96.8 mm SL, rio Karipunas near mouth. Uncat., 1, 85.0 mm SL, rio Madeira, near mouth of rio Karipunas. Uncat.,
28, 32.8–112.2 mm SL, rio Madeira, cofferdam at construction site of Jirau hydroelectric power
plant (former Jirau rapids). Peru: ROM 92440, 1, 117 mm SL, río Tambopata, Madre de Dios
drainage.
Panaqolus nocturnus: Peru: Amazonas: LACM 41729–51, holotype, 138.9 mm SL, río Santiago at La Poza. FMNH 96955, paratypes, 137.8 mm SL, río Santiago at La Poza, outside
mouth of quebrada by airport. LACM 41729–35, paratypes, 4, 71.3–123.4 mm SL, río Santiago
at La Poza. LACM 41723–5, paratypes, 4, 111.1–123.5 mm SL, río Santiago at La Poza. AUM
45558, 6, 68.4–116.6 mm SL, río Marañón, 6.3 km NE of Juan Velasco (Sta. Maria de Nieva).
AUM 45500, 2, 130.5–143.9 mm SL, río Marañón, log riffle, 1.57 km ENE of Juan Velasco (Sta.
Maria de Nieva). AUM 45508, 3, 69.8–101.5 mm SL, río Marañón, 12 km N Imacita. Ecuador:
Pastaza: FMNH 97600, paratypes, 2, 66.7–96.9 mm SL, lower río Bobonaza at Chicherota, ca.
25 km upstream from mouth with río Pastaza. Napo: FMNH 97599, paratypes, 121.5 mm SL,
río Aguarico near Destacamento militar Cuyabeno and confluence of río Cuyabeno—río
PLOS ONE | DOI:10.1371/journal.pone.0165388 November 9, 2016
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New Panaqolus from Xingu River
Aguarico, Napo drainage. USNM 167907, paratypes, 2, 103.5–109.0 mm SL, río Bobonaza,
Napo drainage. USNM 177209, paratype, 92.2 mm SL, río Bobonaza at Chicherota, about 25
km upstream from mouth in río Pastaza. Panaqolus purusiensis: Brazil: Acre: AMNH 12600,
holotype, 106.7 mm SL, vicinity of the mouth of rio Macauã. USNM 94665, 1, 110.6 mm SL,
same data as holotype. MSNM Pi43, 1, 126.4 mm SL, same data as holotype. UFRO-I 17720,
11, 15.5–83.1 mm SL, rio Macauã near mouth with rio Iaco. UFRO-I 17723, 1, 15.7 mm SL,
same data as UFRO-I 17720. MCP 35621, 2, 59.7–78.1 mm SL, rio Riozinho do Andirá at BR364 between Rio Branco and Sena Madureira. Peru: Ucayali: MCP 45733, 2, 107.6–114.0 mm
SL, río Curanja near confluence with río Purús. MUSM 39425, 1, 130.4 mm SL, río Curanja at
mouth with río Purus. Panaqolus sp.: Brazil: Pará: MCP 44235, 2, 45.5–58.4 mm SL, rio Jari
near Monte Dourado. Panaque armbrusteri: Brazil: Pará: INPA 37460, 6, 70.9–74.7 mm SL,
Xingu drainage. ZMA 120.179, 1, 345 mm SL, rio Itacaiunas. Panaque sp.: Brazil: Goiás:
MNRJ 13299, 7, 103.1–122.0 mm SL, rio Tocantins near Minaçu. MNRJ 13297, 1, 209.0 mm
SL, rio Tocantins near Minaçu.
Acknowledgments
Thanks are due to James Maclaine (BMNH), Giorgio Bardelli (MSNM), Jonathan Armbruster
(AUM), Richard Vari (USNM), Leo Smith and Kevin Swagel (FMNH), and Rick Feeney
(LACM) for receiving CAC at their museum collections. Lucia Rapp Py-Daniel (INPA) conferred the vertebrae count for us. Andreas Tanke (Neustadt am Rübenberge, Germany) contributed with valuable discussions about the genus Panaqolus. The sequencing has been
provided free of charge by Claudio Oliveira (UNESP, Botucatu). Photos of live aquarium specimens have been provided by Erlend Bertelson, Julian Dignall, Jens Gottwald, Ingo Seidel, and
Andreas Tanke. Julian Dignall, once again, kindly revised our language use.
Author Contributions
Conceptualization: CAC LMS.
Funding acquisition: CAC LMS.
Investigation: CAC.
Methodology: CAC.
Project administration: CAC.
Resources: CAC LMS.
Supervision: CAC.
Validation: CAC LMS.
Visualization: CAC LMS.
Writing – original draft: CAC LMS.
Writing – review & editing: CAC LMS.
References
1.
Cramer CA (2014) Redescription of Panaqolus purusiensis (LaMonte, 1935) (Siluriformes: Loricariidae) with identification key to the species of the genus. Neotropical Ichthyology 12: 61–70.
PLOS ONE | DOI:10.1371/journal.pone.0165388 November 9, 2016
17 / 19
New Panaqolus from Xingu River
2.
Cramer CA, Bonatto SL, Reis RE (2011) Molecular phylogeny of the Neoplecostominae and Hypoptopomatinae (Siluriformes: Loricariidae) using multiple genes. Molecular Phylogenetics and Evolution
59: 43–52. doi: 10.1016/j.ympev.2011.01.002 PMID: 21241812
3.
Cramer CA, Rapp Py-Daniel LH (in press) A new species of Panaqolus (Siluriformes: Loricariidae)
from the Madeira River basin with remarkable intraspecific color variation. Neotropical Ichthyology.
4.
Fisch-Muller S, Montoya-Burgos JI, Le Bail P-Y, Covain R (2012) Diversity of the Ancistrini (Siluriformes: Loricariidae) from the Guianas: the Panaque group, a molecular appraisal with descriptions of
new species. Cybium 36: 163–193.
5.
Lujan NK, Armbruster JW, Lovejoy NR, López-Fernández H (2015) Multilocus molecular phylogeny of
the suckermouth armored catfishes (Siluriformes: Loricariidae) with a focus on subfamily Hypostominae. Molecular Phylogenetics and Evolution 82: 269–288. doi: 10.1016/j.ympev.2014.08.020 PMID:
25193609
6.
Lujan NK, Steele S, Velasquez M (2013) A new distinctively banded species of Panaqolus (Siluriformes: Loricariidae) from the western Amazon Basin in Peru. Zootaxa 3691: 192–198. PMID:
26167575
7.
Camargo M, Gimenes H Junior, Sousa LM, Rapp Py-Daniel LH (2013) Loricariids of the Middle Xingu
River—Loricariiden des mittleren Rio Xingu. Hannover: Panta Rhei. 288 p.
8.
Lujan NK, Hidalgo M, Stewart DJ (2010) Revision of Panaque (Panaque), with Descriptions of Three
New Species from the Amazon Basin (Siluriformes, Loricariidae). Copeia 2010: 676–704.
9.
Taylor WR, van Dyke GC (1985) Revised procedures for staining and clearing small fishes and other
vertebrates for bone and cartilage study. Cybium 9: 107–119.
10.
Sabaj Pérez MH (2013) Standard symbolic codes for institutional resource collections in herpetology
and ichthyology: an Online Reference. Version 4.0 (28 June 2013). Electronically accessible at http://
www.asih.org/, American Society of Ichthyologists and Herpetologists, Washington, DC.
11.
Lucena CAS, Calegari BB, Pereira EHL, Dallegrave E (2013) O uso de óleo de cravo na eutanásia de
peixes. Boletim Sociedade Brasileira de Ictiologia: 20–24.
12.
Hebert PDN, Cywinska A, Ball SL, DeWaard JR (2003) Biological identifications through DNA barcodes. Proceedings Of The Royal Society Of London Series B-Biological Sciences 270: 313–321.
13.
Roxo FF, Orrego L, Silva GSC, Oliveira C (2015) Rhinolekos capetinga: a new cascudinho species
(Loricariidae, Otothyrinae) from the rio Tocantins basin and comments on its ancestral dispersal route.
ZooKeys 481: 109–130. doi: 10.3897/zookeys.481.8755 PMID: 25685034
14.
Hall TA (1999) BioEdit: a user-friendly biological sequence alignment editor and analysis program for
Windows 95/98/NT. Nucleic Acids Symposium Series 41: 95–98.
15.
Tarnura K, Stecher G, Peterson D, Filipski A, Kumar S (2013) MEGA6: Molecular Evolutionary Genetics Analysis version 6.0. Molecular Biology and Evolution 30: 2725–2729. doi: 10.1093/molbev/
mst197 PMID: 24132122
16.
Werner A (2005) Na also: Wir haben die 400 voll! Die Aquarien und Terrarien Zeitschrift (DATZ) 58:
56–57.
17.
Tanke A (2013) Panaqolus—Ein erster Überblick über eine der populärsten Harnischwelsgattungen.
Die Aquarien und Terrarien Zeitschrift (DATZ) 66: 28–32.
18.
Tanke A (2009) L 398 –ein gelungener Einstieg. Die Aquarien und Terrarien Zeitschrift (DATZ) 62:
22–25.
19.
Costa-Silva GJ, Rodriguez MS, Roxo FF, Foresti F, Oliveira C (2015) Using Different Methods to
Access the Difficult Task of Delimiting Species in a Complex Neotropical Hyperdiverse Group. PLoS
ONE 10: e0135075. doi: 10.1371/journal.pone.0135075 PMID: 26332320
20.
Meyer CP, Paulay G (2005) DNA barcoding: Error rates based on comprehensive sampling. Plos Biology 3: 2229–2238.
21.
Ward RD, Zemlak TS, Innes BH, Last PR, Hebert PDN (2005) DNA barcoding Australia’s fish species.
Philosophical Transactions of the Royal Society B-Biological Sciences 360: 1847–1857.
22.
Garcı́a-Dávila C, Duponchelle F, Castro-Ruiz D, Villacorta J, Quérouil S, et al. (2013) Molecular identification of a cryptic species in the Amazonian predatory catfish genus Pseudoplatystoma (Bleeker,
1962) from Peru. Genetica 141: 347–358. doi: 10.1007/s10709-013-9734-5 PMID: 24008811
23.
Rach J, DeSalle R, Sarkar IN, Schierwater B, Hadrys H (2008) Character-based DNA barcoding allows
discrimination of genera, species and populations in Odonata. Proceedings of the Royal Society B-Biological Sciences 275: 237–247.
24.
Wong EHK, Shivji MS, Hanner RH (2009) Identifying sharks with DNA barcodes: assessing the utility
of a nucleotide diagnostic approach. Molecular Ecology Resources 9: 243–256. doi: 10.1111/j.17550998.2009.02653.x PMID: 21564984
PLOS ONE | DOI:10.1371/journal.pone.0165388 November 9, 2016
18 / 19
New Panaqolus from Xingu River
25.
Stawikowski R (1994) Neu importiert: Harnischwelse aus dem Negro und dem Abacaxı́s. Die Aquarien
und Terrarien Zeitschrift (DATZ) 47: 416–418.
26.
Tan M, Souza LSd, Armbruster JW (2016) A new species of Panaqolus (Siluriformes: Loricariidae)
from the rio Branco. Neotropical Ichthyology 14: e150033.
27.
Ribeiro ED (2013) Diversidade molecular dos Ancistrini (Loricariidae: Siluriformes) reofı́licos da ecorregião Xingu-Tapajós. Manaus: Instituto Nacional de Pesquisas da Amazônia. 51 p.
28.
Montoya-Burgos JI (2003) Historical biogeography of the catfish genus Hypostomus (Siluriformes: Loricariidae), with implications on the diversification of Neotropical ichthyofauna. Molecular Ecology 12:
1855–1867. PMID: 12803637
29.
Pereira LHG, Hanner R, Foresti F, Oliveira C (2013) Can DNA barcoding accurately discriminate
megadiverse Neotropical freshwater fish fauna? BMC Genetics 14: 1–14.
30.
Hubert N, Duponchelle F, Nuñez J, Garcia-Davila C, D P, et al. (2007) Phylogeography of the piranha
genera Serrasalmus and Pygocentrus: implications for the diversification of the Neotropical ichthyofauna. Molecular Ecology 16: 2115–2136. doi: 10.1111/j.1365-294X.2007.03267.x PMID: 17498236
31.
Stawikowski R (1988) Harnischwelse aus südlichen Amazonaszuflüßen. Die Aquarien und Terrarien
Zeitschrift (DATZ) 41: 556–558.
32.
Stawikowski R (1998) Neue L-Nummern aus Klarwasserflüssen in Pará. Die Aquarien und Terrarien
Zeitschrift (DATZ) 51: 686.
33.
Werner A (2005) Welse aus dem Rio Anapu. Die Aquarien und Terrarien Zeitschrift (DATZ) 58: 32.
34.
Stawikowski R (1990) Loricariiden, diesmal aus dem Rio do Pará. Die Aquarien und Terrarien Zeitschrift (DATZ) 43: 647.
PLOS ONE | DOI:10.1371/journal.pone.0165388 November 9, 2016
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