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Astyanax taurorum a new species from dos Touros River, Pelotas River
drainage, an upland southern Brazilian river (Characiformes: Characidae)
Carlos Alberto S. de Lucena1, Amanda Bungi Zaluski1, Zilda Margarete Seixas de Lucena1
1Museu de Ciências e Tecnologia, Pontifícia Universidade Católica do Rio Grande do Sul. Avenida Ipiranga 6681,
Caixa Postal 1491, 90619-900 Porto Alegre, RS, Brazil.
Corresponding author: Carlos Alberto S. de Lucena (lucena@pucrs.br)
http://zoobank.org/2C4F6889-11BA-4C8A-9E1C-4C6CF36D50C6
ABSTRACT. A new species of Astyanax belonging to the Astyanax scabripinnis complex is described from dos Touros River,
tributary of the Pelotas River, Uruguay River basin. Astyanax taurorum sp. nov. is distinguished from other species of the Astya-
nax scabripinnis species complex by having two humeral spots, the first vertically elongated; teeth of inner row of premaxilla
with three to five cusps; 2–3 (modes 2 or 3) maxillary teeth; 20–23 (mode 22) branched anal-fin rays; 13–15 (mode 14) gill
rakers on lower branch of the first branchial arch; 20–23 (mode 21) total gill rakers in first branchial arch; 33–36 (mode 35)
perforated lateral line scales. Astyanax taurorum sp. nov. is similar to Astyanax paris; nevertheless, it can be readily distin-
guished from it by having a smaller head depth (73.6-83.1% vs. 86.4–95.6%) and smaller interorbital width (24.1–28.0%
vs. 30.8–32.8%). In addition, it differs from A. paris by the presence a posttemporal hook-shaped posterodorsal margin.
KEY WORDS. Taxonomy, Rio Grande do Sul, Uruguay River, distribution.
INTRODUCTION
The fishes of the genus Astyanax Baird & Girard, 1854 in-
habit Neotropical drainages from the Colorado River in Texas and
New Mexico in the United States to Northern Patagonia, Argen-
tina (Menni 2004, López et al. 2008, Ornelas-Garcia et al. 2008).
As suggested by phylogenetic analyses based on morphological
(Mirande 2010) and molecular evidence (Javonillo et al. 2010,
Oliveira et al. 2011), Astyanax is not monophyletic. The genus
comprises 150 valid species (Eschmeyer et al. 2016), and it is still
defined as in Eigenmann (1921, 1927) (for the characters, see
Marinho and Ohara 2013). The Astyanax scabripinnis complex is
a non-monophyletic group with 29 species (Ingenito and Duboc
2014: tab. 1). It is characterized, according to Bertaco and Lucena
(2006), by possessing the deepest and most robust body area close
to the middle length of the pectoral fins, a robust head, snout
short and abrupt, body depth smaller than 41% of SL, reduced
number of branched anal-fin rays (13-23, rarely 22 or 23 rays),
presence of one or two humeral spots, and a dark mid-lateral
body stripe extending to the tip of the middle caudal-fin rays.
Currently, there are 19 recognized species of Astyanax from
the Uruguay River, Laguna dos Patos system to the Tramandaí
River drainage: A. aramburui Protogino, Miquelarena & López,
2006; A. bagual Bertaco & Vigo, 2015; A. brachypterygium Bertaco
& Malabarba, 2001; A. cremnobates Bertaco & Malabarba, 2001;
A. douradilho Bertaco, 2014; A. dissensus Lucena & Thofehrn,
2013; A. eigenmanniorum (Cope, 1894); A. henseli Melo & Buckup,
2006; A. lacustris (Luetken, 1875); A. laticeps (Cope, 1894); A.
obscurus (Hensel, 1870); A. ojiara Azpelicueta & Garcia, 2000;
A. paris Azpelicueta, Almirón & Casciotta, 2002; A. pirabitira
Lucena & Bertcaco, 2013; A. procerus Lucena, Castro & Bertaco,
2013; A. saguazu Casciotta, Almirón & Azpelicueta, 2003; A.
stenohalinus Messner, 1962), Astyanax sp. aff. fasciatus, sensu
Melo and Buckup (2006); and A. xiru, Lucena, Castro & Bertaco,
2013. While studying the genus Astyanax from the Pelotas River
drainage, a new species of the Astyanax scabripinnis complex was
found and it is described herein.
MATERIAL AND METHODS
The examined material belongs to the following institu-
tions: Museu de Ciências e Tecnologia, Pontifícia Universidade
Católica do Rio Grande do Sul, Porto Alegre (MCP); Museu de
Zoologia, Universidade de São Paulo, São Paulo (MZUSP); Mu-
séum d’histoire naturelle, Genève (MHNG); Universidade Federal
do Rio Grande do Sul, Porto Alegre (UFRGS).
RESEARCH ARTICLE
ZOOLOGIA 34: e20174 | DOI: 10.3897/zoologia.34.e20174 | September 18, 2017 1 / 8
ZOOLOGIA 34: e20174
ISSN 1984-4689 (online)
zoologia.pensoft.net
Counts and measurements follow Fink and Weitzman
(1974) and Bertaco and Lucena (2006) with the addition of
the head depth, measured at the vertical through posterior
margin of the orbit. Measurements were preferentially taken
on the left side of specimens using callipers (0.1 mm approxi-
mation). Counts of vertebrae, supraneurals, teeth of dentary,
unbranched dorsal, and anal-fin rays taken from cleared and
stained (c&s) specimens prepared according to the protocol of
Taylor and van Dyke (1985). Vertebral counts included the four
vertebrae of the Weberian apparatus, and the terminal centrum
counted as a single element. In the description, the frequency
of each count is given in parentheses after the respective value.
In the material examined, the total number of specimens in
the lot follows each catalogue number, and in parentheses is
the number of specimens measured and counted with their
respective standard length range. HL stands for head length
throughout.
The Laguna dos Patos system and the Tramandaí River
drainage, follow definitions of Malabarba (1989) and Malabarba
and Isaia (1992), respectively. Data for A. paris are from Azpeli-
cueta et al. (2002), except when said otherwise.
TAXONOMY
Astyanax taurorum sp. nov.
http://zoobank.org/F15C02B5-AF1B-4052-A67A-741560E1468F
Fig. 1, Table 1
Types series. Brazil, Rio Grande do Sul, Bom Jesus. Holo-
type: Tributary of dos Touros River ca. 4 km northeastern of the
road BR-285, Pelotas River drainage, 1,056 m a.s.l., 28°41’06”S
50°12’51”W, 12 Feb 2016, J. Pezzi da Silva and E. Pereira leg.,
MCP 49468, 80.7 mm SL. Paratypes: Tributary of dos Touros
River, on the road Silveira-Rondinha, ca. 28°39’08”S 50°18’25”W,
14 Jan 1989, C. Lucena, P. Azevedo and E. Pereira leg., MCP
14370, 20 (17, 22.2-82.6 mm SL, 3 c&s, 29.6–62.6 mm SL).
Same locality of MCP 14370, MZUSP 120697, 1, 29.9 mm SL.
Dos Touros River, dowstream dam, Pelotas River drainage, road
Rondinha – Silveira, 998 m a.s.l., 28°38’44”S, 50°17’06”W, 12 Feb
2016, J.P. Silva and E. Pereira leg., MCP 49467, 1, 75.7 mm SL.
Diagnosis. Astyanax taurorum sp. nov. belongs to the
A. scabripinnis species complex and is distinguished from the
species of that complex by having two humeral spots (vs. one
in A. courensis Bertaco, Carvalho & Jerep, 2010, A intermedius
Eigenmann, 1908, A. jenynsii (Steindachner, 1877), A. jordanensis
Vera Alcaraz, Pavanelli & Bertaco, 2009, A. laticeps (Cope, 1894),
A. microschemos Bertaco & Lucena, 2006, A. serratus Garavello &
Sampaio, 2010, A. totae Haluch & Abilhoa, 2005, A. rivularis and
A. varzeae Abilhoa & Duboc, 2007); 20–23 total gill rakers in first
branchial arc (vs. 16 in A. jacobinae Zanata and Carmelier, 2008,
16–17 in A. gymnogenys Eigenmann, 1911, 18 in A. burgerai Za-
nata & Carmelier, 2009, 17–18 in A. troya Azpelicueta, Casciotta
& Almirón, 2002, 18–19 in A. epiagos Zanata & Carmelier, 2008,
17–19 in A. ojiara Azpelicueta & Garcia, 2000, A. cremnobates
Bertaco & Malabarba, 2001 and A. leonidas Azpelicueta, Casciotta
& Almirón, 2002); 13–15 gill rakers on the lower branch of the
first branchial arch (vs. 9–10 in A. turmalinensis Triques, Voino
& Caiafa, 2003); 33–36 perforated lateral line scales (vs. 39–41 in
A. gymnogenys and A. eremus Ingenito & Duboc, 2014, 40–43 in
A. guaricana Oliveira, Abilhoa & Pavanelli, 2013); 20–23, usually
21 or 22, branched anal-fin rays (vs. 18–19 in A. burgerai, 13–16
in A. goyanencis Miranda Ribeiro, 1944, 16–20, usually 16 or 17
in A. serratus Garavello & Sampaio, 2010, 14–18 in A. microsche-
mos, 15–18 in A. totae, 12–16 in A. brachypterychium, 14–18 in A.
cremnobates, and 13–17 in A. epiagos and A. jordanensis); inner
row of premaxilla with teeth bearing three to five cusps (vs.
heptacuspid in A. ita Almirón, Azpelicueta & Casciotta, 2002
and A. pirabitira Lucena, Bertaco & Berbigier, 2013); 2–3 max-
illary teeth (vs. 1 in A. obscurus Hensel, 1870, A. ojiara, A. troya
Azpelicueta, Casciotta & Almirón, 2002, A. guaricana, A. courensis
and A. ita Almirón, Azpelicueta & Casciotta, 2002; 0–1 in A.
pirapuan Tagliacollo, Britzke, Silva & Benine, 2011); length of
anal-fin base 23.6–28.0% (mean = 26.3%) of SL (vs. 19.8–24.3%
(mean = 21.5%) of SL in A. eremus and 30.2% in A. scabripinnis
Jenyns, 1842 in the holotype); body depth 33.8–37.6% of SL (vs.
26.9–29.7% in A. microschemos, and 27.3–31.3% in A. eremus);
head length 29.0–30.5% of SL (vs. 22.9–25.1% in A. gymnogenys,
21.9–27.1% in A. courensis, 26.6–28.2% in A. turmalinensis, and
23.9–26.6% of SL in A. guaricana); eye diameter 29.0–32.4% of
Table 1. Morphometric data of Astyanax taurorum sp. nov. The range
includes the holotype; n = number of specimens; SD = standard
deviation.
Holotype n Range Mean SD
Standard length (mm) 80.7 14 54.7–82.6 69.6 –
Percents of standard length
Depth at dorsal-fin origin 34.9 14 33.8–37.6 35.9 0.99
Predorsal length 52.8 14 51.6–54.9 53.5 0.99
Prepectoral length 29.0 14 27.8–30.0 29.1 0.61
Preanal length 66.4 14 65.0–68.7 66.4 1.04
Prepelvic length 50.5 14 49.1–52.2 51.0 0.88
Dorsal-fin length 25.9 14 22.3–26.6 24.6 1.24
Pectoral-fin length 22.7 14 18.6–22.7 20.6 1.22
Pelvic-fin length 15.6 14 14.4–16.8 15.2 0.62
Anal-fin base length 26.9 14 23.6–28.0 26.3 1.08
Anal-fin lobe length 17.0 13 13.2–18.3 16.3 1.56
Caudal peduncle length 14.0 14 12.7–15.7 14.2 0.88
Caudal peduncle depth 11.4 14 11.0–12.7 11.5 0.42
Head length 29.1 14 29.0–30.5 29.9 0.75
Percents of head length
Head depth 83.1 14 75.1–86.7 81.6 2.98
Snout length 25.1 14 23.8–28.8 27.1 1.58
Interorbital width 26.7 14 24.7–28.0 26.4 0.99
Horizontal orbit diameter 30.3 14 29.0–32.4 30.7 1.22
Upper jaw length 38.4 14 36.7–41.5 39.2 1.60
C.A.S. de Lucena et al.
ZOOLOGIA 34: e20174 | DOI: 10.3897/zoologia.34.e20174 | September 18, 20172 / 8
Figure 1. Astyanax taurorum sp. nov., MCP 49468, 80,7 mm SL, holotype, tributary of dos Touros River, Rio Grande do Sul, Brazil.
Figures 2–3. (2) Head depth as function of head length for Astyanax paris (y = -1.517 +(0.996X), R = 0.952, and Astyanax taurorum sp. nov.
(y = -5·158+(1.037X), R = 0.932. Dotted lines, confidence interval of 95%; (3) Astyanax taurorum sp. nov. Posterodorsal region of head
(lateral view, right side); EXS = Extrascapular, PTE = posttemporal, SCL = supracleithrum. White arrow indicates the hook on posterodorsal
region of posttemporal bone (see text). Scale bar = 0.2 mm.
HL (vs. 24.4–26.1% in A. gymnogenys, and 36.8–40.3% in A. jaco-
binae); snout length 23.8–28.8% of HL (vs. 16.0–20.4% in A. pa-
ranae); and interorbital length 24.7–28.0% of HL (vs. 35.2–37.8%
in A. gymnogenys, 29.6–37.3% in A. jacobinae, 30.4–34.5% in A.
goyanensis, 37.5–47.1% in A. intermedius, 29.8–37.7% in A. varzea,
32.7–40.9% in A. guaricana, 30.6–35.7% in A. jordanensis, 40.7%
in A. scabripinnis holotype), and 31.7–39.2% in A. pirapuan).
Within the Astyanax scabripinnis complex, Astyanax taurorum sp.
nov. is most similar to A. paris Azpelicueta, Almirón & Casciotta,
2002 – species known from the type locality, Arroio Fortaleza,
tributary of upper Uruguay River, Argentina – with which most
counts and morphometric percentages overlap. Nevertheless,
Astyanax taurorum sp. nov. differs from A. paris by the presence
of hooks on branched anal-fin rays (vs. secondary sexual dimor-
phism absent in A. paris), interorbital width 24.7–28.0% HL (vs.
28.4–32.8% HL) and head depth 73.6–86.7% HL (vs. 86.4–96.6%
HL) (Fig. 2) (Table 2), and by having posterodorsal margin of
the posttemporal hook-shaped (Fig. 3) (see Discussion). Astyanax
taurorum sp. nov. is distinguished from the other species in the
genus by the following combination of characters: presence of
two conspicuous humeral spots, the first one vertically elongated
with the upper portion enlarged, but narrowing ventrally; dark
midlateral horizontal stripe; conspicuous caudal spot extending
posteriorly to the middle of caudal-fin rays; 20–23 branched
anal-fin rays; 20–23 total gill rakers in first branchial arc; 33–36
perforated lateral line scales; 5–7 scale rows between lateral line
A new species of Astyanax from southern Brazil
ZOOLOGIA 34: e20174 | DOI: 10.3897/zoologia.34.e20174 | September 18, 2017 3 / 8
and pelvic-fin origin; outer row of premaxilla with tricuspid
teeth; teeth in inner row of premaxilla with three to five cusps;
2–3 tricuspid teeth in the maxilla, head length 29.0–30.5% of
SL; body depth 33.8–37.6% of SL; interorbital width 24.7–28.0%
of HL; eye diameter 29.0–32.4% of HL, and length of anal-fin
base 23.6–28.0% of SL.
Description. Morphometric data summarized in Table 1.
Body compressed and moderately elongate, greatest body depth
at vertical through near middle length of pectoral fin. Dorsal
profile of head convex from tip of snout to vertical through
nostrils, straight from that point to vertical through posterior
border of orbital, slanted until tip of supraoccipital spine. Snout
relatively slender. Dorsal profile of body convex from tip of su-
praoccipital bone to dorsal-fin origin; straight from that point
to end of caudal peduncle. Ventral body profile convex from
mandibular symphysis to pelvic-fin origin, nearly straight from
that point to anal-fin origin, and slanted along anal-fin base.
Dorsal and ventral profiles of caudal peduncle nearly straight.
Mouth terminal or slightly subterminal, slit below hor-
izontal passing through middle of eye. Posterior tip of maxilla
extending between vertical through anterior margin of orbit and
the vertical through middle of orbit. Two tooth rows in premaxilla;
outer row with 3*(2), 4(13), or 5(5) tricuspid teeth; inner row with
five teeth, usually bearing four cusps on first tooth, five cusps on
second to fourth tooth, three cusps on fifth tooth. Maxilla with 2(8)
or 3(8) tricuspid teeth. Dentary with four large pentacuspid teeth,
followed by seven small tricuspid teeth and one conical tooth (two
c&s). Median cusp in all cuspidate teeth longer than remaining
cusps; cusp tips slightly curved inwardly on dentary (Fig. 4).
Dorsal-fin rays ii, 9 (23); first unbranched ray short, one-
half length of second ray. Distal margin of dorsal fin slightly con-
vex. Dorsal-fin origin slightly behind middle of SL. Adipose-fin
origin at vertical through base of fifth or sixth last anal-fin rays.
Anal-fin rays iii-iv 20(2), 21(6), 22(9), or 23(4). Anal-fin origin
posterior to vertical through base of last dorsal-fin ray. Pecto-
ral-fin rays i, 11(1), 12(7), 13(11), or 14(1). Tip of pectoral-fin
tip ending one scale before or, occasionally, reaching pelvic-fin
insertion. Pelvic-fin rays i, 7(23), tip of fin not reaching anal-fin
origin. Axillary scale present.
Table 2. Morphometric data of Astyanax paris.* = Values from Azpelicueta et al. (2002). **The range includes the holotype. Museo de La
Plata (MLP), Muséum d’histoire naturelle (MNHG), Museu de Ciências e Tecnologia PUCRS (MCP). n = number of specimens, m = mean.
Measurements
Holotype Paratypes Topotypes
MLP 9584 MLP 9586 MNHG 2623.65 MCP 34461
n Range** m n Range** m n Range m
Standard length (mm) 75.6* 7 51.3–86.1* 72.4 3 70.3–73.1 71.6 4 66.9–73.5 70.4
Percentages of head lenght
Head depth 95.6 7 86.4–96.6 93.1 3 90.7–92.6 91.8 4 88.2–92.6 89.6
Interorbital width 32.8* 15 28.4–32.8* 30.8* 4 30.8–32.1 31.2
Figure 4. Maxilla, premaxilla and dentary of Astyanax taurorum sp.
nov., MCP 14370, paratype, 62.6 mm SL, lateral view of right side.
Scale bar = 0.5 mm.
C.A.S. de Lucena et al.
ZOOLOGIA 34: e20174 | DOI: 10.3897/zoologia.34.e20174 | September 18, 20174 / 8
Caudal-fin forked, lobes similar in size.
Lateral line complete with 33(2), 34(2), 35(8), or 36(5)
perforated scales. Scale rows between dorsal-fin origin and lateral
line 6(5) or 7(12); scale rows between lateral line and pelvic-fin
origin 5(5), 6(13), or 7(1); scale rows between lateral line and
anal-fin origin 5(1), 6(15), or 7(1); scale rows around caudal
peduncle 14 (8), 15(5), or 16(2).
Precaudal vertebrae 13 (3); caudal vertebrae 18(2) or 19(1);
total vertebrae 31(2) or 32(2). Supraneurals 5(3). Gill rakers on
upper branch 6(1), 7(11) or 8(11) and on lower branch 13(7),
14(14), or 15(2) in first branchial arch; total gill rakers in first
branchial arch 20(3), 21(13), 22(6), or 23(1).
Color in alcohol. Dorsal and dorsolateral portions of head
and body dark brown. Scales on lateral of body with dark brown
chromatophores sometimes concentrated on anterior border.
Two conspicuous humeral spots. Anterior humeral spot vertically
elongate with upper portion wider, located on second to third or
fourth scale vertical series, extending three horizontal scale series
above lateral line; lower portion narrow, extending on the lateral
line and one or two horizontal scale series below it. Posterior
humeral spot large, absent in small specimens (22.8–29.4 mm
SL), reaching but not surpassing lateral line ventrally, extending
on two or three horizontal scale series and three vertical scale
series. Humeral spots separated by a clear area occupying two
or three vertical scale series. Dark midlateral strip inconspicu-
ous anteriorly, but conspicuous posteriorly from about vertical
through middle of dorsal-fin base to caudal peduncle; absent
in small specimens (22.8–29.4 mm SL). Caudal peduncle spot
triangular, extending over median caudal-fin rays. Scattered dark
chromatophores on dorsal, anal, and caudal fins. Pectoral and
pelvic-fins hyaline or covered by sparse dark chromatophores.
Color in life. Overall body olive green, silvery below lateral
line. Humeral spots and caudal peduncle spot conspicuous. Dor-
sal, anal, pelvic and caudal fins reddish. Pectoral-fin yellowish.
Dark brown blotches located on anterior portion of scales.
Sexual dimorphism. Hooks on anal-fin rays of four speci-
mens with 75.4 to 80.6 mm SL (MCP 14370). Hooks short,
conical or slightly retrorse found on the first or third to eighth
branched rays, along the posterolateral margin of the posterior
branch. One pair on each segment. One specimen with a single
hook on the third branched anal-fin ray and another specimen
with a very small hook on the first branched ray and small
protuberances on other rays.
Distribution and habitat. Astyanax taurorum sp. nov. is
known from the dos Touros River drainage, tributary of Pelotas
River, which in turn is a tributary of Uruguay River (Fig. 5). The
Pelotas River drainage is located in the region named “Campos
de Altitude do Planalto das Araucárias (= Araucaria Plateau in
Bertaco et al. 2016)” or “Campos de Cima da Serra”, which has
a high level of endemism of fishes (Malabarba et al. 2009, Berta-
co et al. 2016: 430) and other groups of animals (for example:
sponges, Ribeiro et. al. 2009; crustaceans, Bond-Buckup et al.
2009). The dos Touros River tributary, type locality of Astyanax
taurorum sp. nov., has a low to medium flow, transparent waters
with stones and rocks on the bottom and moderate emergent
marginal vegetation (Fig. 6). Four characid species were caught
along with Astyanax taurorum sp. nov.: Bryconamericus patriciae
Silva, 2004, B. iheringi Boulenger, 1887, Cheirodon interruptus
Jenyns, 1842, and Oligosarcus brevioris Menezes, 1987.
Etymology. The specific name taurorum, is derived from
the Latin masculine noun taurus (second declension, meaning
bull) inflected in the plural and genitive case. Therefore taurorum
Figures 5–6. (5) Distribution of Astyanax taurorum sp. nov., white circle = type-locality. The symbol represents more than one locality;
(6) stream tributary of dos Touros River, type locality of Astyanax taurorum sp. nov.
A new species of Astyanax from southern Brazil
ZOOLOGIA 34: e20174 | DOI: 10.3897/zoologia.34.e20174 | September 18, 2017 5 / 8
means “of the bulls” in reference to “rio dos Touros“ (= Portu-
guese, which means “river of the bulls”) the type locality.
Conservation status. Astyanax taurorum sp. nov. is likely
rare and occurs in low densities. All type specimens were collected
in the dos Touros River drainage, during two field trips in 1989
and 2016. Over the last four decades (from 1980 to 2016), six
field trips to the dos Touros River system have been conducted by
the MCP team, two of which with the sole purpose of collecting
specimens of A. taurorum. Unfortunately, no specimens were
collected in 2015, and only two were found in 2016. The Museu
de Ciências Naturais (FZB, Porto Alegre) and Universidade Federal
do Rio Grande do Sul also conducted field surveys in that region,
but no specimens of A. taurorum sp. nov. were obtained. Despite
the reduced number of specimens collected and the apparently
restricted geographical distribution of the new species, we did
not assign Astyanax taurorum sp. nov. to any threat category
because we the lack biology data for it. Instead, we considered
A. taurorum sp. nov. as data deficient (DD) (IUCN 2014).
Additional material. Types: Argentina: Astyanax paris,
MNHG 2623.065 paratypes, 3 (70.3–73.1 mm SL), arroio Fortale-
za. MCP 34461 topotypes, 5 (4, 66.9–73.5 mm SL, 1 c&s 68.2 mm
SL). Astyanax troya, MCP 28438 paratypes. All c&s specimens:
Types: Brazil: Astyanax cremnobates, paratypes MCP 11650 (2);
Astyanax dissensus, paratypes MCP 17361 and MCP 47518 (1);
Astyanax douradilho, paratypes MCP 25700 (3);Astyanax elachy-
lepis, paratype MCP 16054 (1); Astyanax eremus, paratypes MCP
46942 (1); Astyanax jordanensis, paratype MCP 41915(1); Astya-
nax microschemos, paratype MCP 34366 (1); MCP 19783 (5);
Astyanax pelecus, paratype MCP 17919 (1); Astyanax pirabitira,
paratypes MCP 14390 (6); Astyanax utiariti, paratypes MCP 40041
(3); Astyanax procerus, paratype MCP 25513 (1); Astyanax xiru,
paratype MCP 21730 (1). Non-types: Astyanax lacustris, MCP
20339 (1); Astyanax eigenmanniorum MCP 25122 (1); Astyanax
henseli MCP 48121 (3); Astyanax aff fasciatus MCP 21627 (1);
Astyanax laticeps, MCP 25690 (1), MCP 17614 (1), MCP 27619
(2); Astyanax obscurus MCP 26125 (2)); Astyanax saguazu MCP
16808 (1), and MCP 4000 (3); Astyanax sp. UFRGS 14052 (6),
UFRGS 14051 (6) and UFRGS 14055 (6); Hyphessobrycon anisitsi
MCP 21633 (2); Markiana nigripinnis MCP 17086 (1).
DISCUSSION
The Astyanax scabripinnis species complex is not a mono-
phyletic group; this clustering, however artificial, facilitates
discussions and comparisons on the diversity of the genus ac-
cording to Bertaco and Lucena (2006). These authors presented
a series of morphological characters that delimit this complex,
which are mostly found in A. taurorum sp. nov. except for the
abrupt snout (slender in A. taurorum sp. nov.).
Mirande (2010) presented the most encompassing, mor-
phology-based phylogeny of Characidae. Astyanax taurorum sp.
nov. has all synapomorphies that define node 201 in that anal-
ysis (sister group of Tetragonopterinae clade): dorsal expansion
in the rhinosphenoid absent (character 48, state 0), and tubule
with anterior branch parallel to anterior margin of maxilla,
reaching a third of its length (character 98, state 1). Node 201
has two branches, the Hyphessobrycon luetkenii clade and node
200. The new species shares all synapomorphies of node 200:
fourth infraorbital approximately square, or more developed
longitudinally than dorsoventrally (67, state 0); coronomecke-
lian situated dorsal to Meckelian cartilage (character 110, state
1); 24 or less branched anal-fin rays (288, state 0). Node 200
has two branches named Astyanax paris and node 199 clades.
For now, we note that A. taurorum shares, with the former
clade, “the abrupt decrease in size of dentary teeth (character
148, state 1)” and not the synapomorphy of clade 199 “ventral
margin of horizontal process of anguloarticular perpendicular
to laterosensory canal of dentary from medial view”. We have
examined some species of the clade at node 199, mostly included
in the Astyanax clade (node 267) (e.g., Astyanax lacustris Lutken,
1875 and A. eigenmanniorum Cope, 1894, Markiana nigripinnis
Perugia, 1891, and Hyphessobrycon anisitsi Eigenmann, 1907),
and other representatives of Astyanax not analyzed by Mirande
(see Additional material). None of them have a posterodorsal
margin with posttemporal hook-shape, as it is the case with A.
taurorum, though some species have an enlarged posterodorsal
margin, which is not hook-shaped (see Mirande 2010: fig. 48).
Astyanax is represented in the Laguna dos Patos, Traman-
daí River, and Uruguay River drainages, by 20 species, eight
of which have restricted distribution within these drainages
(Fig. 5): A. bagual Bertaco & Vigo, 2015 (middle Taquari-Antas
River), A. brachypterigium (upper Pelotas River and upper das
Antas River), A. cremnobates (upper das Antas River, upper Caí
River and upper Maquiné River), A. douradilho (middle and
upper portions of Maquiné River), A. obscurus (upper das Antas
and upper Caí Rivers), A. ojiara (upper Yaboty-Guazu River),
A. paris (upper Yaboty-Guazu River), and A. taurorum sp. nov.
(upper dos Touros River). With the exception of A. bagual and
A. douradilho, these species are included in the A. scabripinnis
complex (Ingenito and Duboc 2014) and are mainly found in
headwater streams. Astyanax laticeps, in contrast, is the only
species of the Astyanax scabripinnis complex that is widely dis-
tributed, occurring in the three main drainages of Rio Grande
do Sul, besides the southern and southeastern coastal rivers of
Brazil (Lucena and Bertaco 2010). Recent descriptions of new
species in different genera (e.g., characiforms Bryconamericus
patriciae, Hollandichthys taramandahy Bertaco & Malabarba,
2013, siluriforms Trichomycterus tropeiro Ferrer & Malabarba,
2011, or perciforms Australoheros taura Ottoni & Cheffe, 2009
and Crenicichla lucenai Mattos, Schindler, Ottoni & Cheffe,
2014), with restricted distributions on the headwaters men-
tioned above, as well as the occurrence of 43 undescribed
fish species in these drainages (Bertaco et al. 2016: 428),
demonstrate the importance of conservation of this type of
environment, as remarked by other authors (e.g., Ferrer and
Malabarba 2011, Ferrer et al. 2015).
C.A.S. de Lucena et al.
ZOOLOGIA 34: e20174 | DOI: 10.3897/zoologia.34.e20174 | September 18, 20176 / 8
ACKNOWLEDGEMENTS
We are grateful to the following colleagues: Vinicius
Bertaco (Museu de Ciências Naturais-FZB) for offering sugges-
tions to an earlier version of this manuscript; Carlos Oliveira
(Universidade Estadual de Maringá) for providing information
about the genus Astyanax; Alessio Datovo (MZUSP), Luiz R. Mala-
barba (UFRGS), and Sonia Fisch-Muller (MHNG), who provided
material for this study; and José Pezzi da Silva, Rafael Angrazani
and Edson Pereira for their efforts in the field. Paulo Lucinda,
Universidade Federal do Tocantins, for his help with the specific
name. We thank CNPq/PUCRS for grants received to ABZ.
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Submitted: 27 September 2016
Received in revised form: 21 March 2017
Accepted: 11 May 2017
Editorial responsibility: Paulo Buckup
Author Contributions: CASL and ZMSL analyzed the data and
wrote the paper. ABZ examined specimens and take the counts
and measurements.
Competing Interests: The authors have declared that no competing
interests exist.
C.A.S. de Lucena et al.
ZOOLOGIA 34: e20174 | DOI: 10.3897/zoologia.34.e20174 | September 18, 20178 / 8
