Two new species of Rineloricaria (Siluriformes: Loricariidae) from the rio Iguaçu basin, southern Brazil
Author
Ingenito, Leonardo F. S.
Author
Ghazzi, Miriam S.
Author
Duboc, Luiz F.
Author
Abilhoa, Vinícius
text
Neotropical Ichthyology
2008
2008-12-31
6
3
355
355
http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1679-62252008000300009&lng=en&tlng=en
journal article
10.1590/S1679-62252008000300009
1982-0224
5419780
Rineloricaria maacki
,
new species
Figs. 3-5
Holotype
.
MNRJ 31158
, male,
108.4 mm
SL,
Brazil
,
Paraná
,
União
da Vitória
,
rio Iguaçu
,
51°10’31”W
26°10’16”S
,
25 May 2003
,
G. Otto.
Paratypes
.
MHNCI 11457
,
2
(
1 male
,
1 female
), 113.0-128.0 mm SL, collected with the
holotype
.
MHNCI 11455
,
1
(female),
102.8 mm
SL,
Brazil
,
Paraná
,
Lapa
, areal
Água Azul
,
rio Iguaçu
,
50°11’34”W
25°47’34”S
,
22 Feb 2001
,
L. F. Duboc
,
L. F. S. Ingenito
&
F. Wegbecher
.
MHNCI 11682
,
1
(female),
79.7 mm
SL,
Brazil
,
Paraná
,
Lapa
, areal
Água Azul
,
rio Iguaçu
,
50°11’34”W
25°47’34”S
,
10 Nov 2000
,
L. F. Duboc
&
L. F. S. Ingenito.
NUP 2540, 3 (
1 male
,
1 female
, 1 c&s female),
110.8-133.5 mm
SL,
Brazil
,
Paraná
,
Cruz Machado
/
Bituruna
,
Foz do Areia
rerservoir,
rio Iguaçu
, approx.
51°37’W
26°00’S
,
26 Oct 1998
, NUPELIA. NUP 3059, 1 (male),
136.2 mm
SL,
Brazil
,
Paraná
,
Cruz Machado
/
Bituruna
,
Foz do Areia
reservoir,
rio Iguaçu
, approx.
51°37’W
26°00’S
,
6 Oct 1999
,
COPEL
.
Diagnosis.
Rineloricaria maacki
is easily distinguished from all
Rineloricaria
species
except from
R. latirostris
,
R. microlepidogaster
,
R. misionera
,
R. baliola
,
R. tropeira
, and
R. anhaguapitan
by having a naked pectoral girdle and the abdomen covered by plates (
vs.
pectoral girdle and abdomen completely covered by plates). In addition, the complete covering of plates of the abdominal region of
Rineloricaria maacki
distinguish it from
R. setepovos
(that has the abdo- 360 Two new species of
Rineloricaria
from the rio Iguaçu basin men naked); from
R. aequalicuspis
,
R. maquinensis
, and
R. malabarbai
(that have the abdomen variably covered, sometimes naked); and from
R. reisi
(that has the abdomen almost naked with few irregular platelets).
Rineloricaria maacki
can be distinguished from
R
.
latirostris
by the presence of five dorsal transverse bands (
vs.
six bands) and by having the dorsal unbranched caudal-fin ray not prolonged (
vs
. dorsal unbranched caudal-fin ray produced as a long filament); from
R. misionera
, it is distinguished by having the pectoral girdle completely naked (
vs
. pectoral girdle with, a few small, well-
Fig. 3.
Rineloricaria maacki
, holotype, male, MNRJ 31158, 108.4 mm SL, rio Iguaçu, União da Vitória, Paraná, Brazil.
L. F. S. Ingenito, M. S. Ghazzi, L. F. Duboc & V. Abilhoa
361
Fig. 4.
Rineloricaria maacki
, paratype, female, MHNCI 11457, 113.00 mm SL, rio Iguaçu, União da Vitória, Paraná, Brazil.
defined lateral plates). It can be distinguished from both
R. anhaguapitan
and
R. baliola
by its snout having a naked area not reaching to anterior most pore of infraorbital ramus of sensory canal species (
vs
. snout with a naked area reaching to anterior most pore of infraorbital ramus of sensory canal) and by having all fins, except the dorsal fin, without a distal dark band (
vs
. wide dark band covering the distal onehalf of all fins in
R. baliola
and the same color pattern on dorsal, anal and caudal fins in
R. anhaguapitan
); and from
R. microlepidogaster
, by having abdominal plates between lateral abdominal bones arranged in four (
vs
. five to six) series and larger than abdominal plates of this species. Furthermore,
R. maacki
can be distinguished from
R. microlepidogaster
by having the pectoral fin usually not reaching the pelvic-fin origin (
vs
. pectoral fin surpassing pelvic-fin origin).
Description.
Morphometric data in
Table 2
. Head and body deeply depressed. Body depth greatest at dorsal-fin origin. Head triangular in dorsal view. Dorsal profile slightly convex from the tip of the snout to dorsal-fin origin, thereafter gradually depressed up to caudal-fin base. Ventral profile of body nearly straight from snout tip to anal-fin origin, then becoming more depressed towards caudal-fin base. Caudal peduncle depressed forming lateral keels with 11 (3*), 12 (4) or 13 (2) coalesced plates from 28 (1), 29 (4*) or 30 (4) total lateral plates in middle series. Five lateral series of plates, mid-dorsal series present. Scapular bridge completely naked. Abdomen completely covered by plates. Four series of abdominal plates irregularly distributed. Pre-anal plate present and anteriorly rounded by three polygonal plates. Lateral abdominal plates four (3*), five (3) or six (3). Dorsal-fin base with five plate rows.Anal-fin base with two (2) or three (7*) plate rows. Two 362 Two new species of
Rineloricaria
from the rio Iguaçu basin
(2) or three (7*) rows of plates between urogenital pore and anal fin. Plate counts on opposite sides of body usually different, except at dorsal- and anal-fin bases.
Top of head and parieto-supraocciptal smooth. Ridges of parieto-supraocciptal slightly divergent posteriorly. Plates of first three mid-dorsal series without evident ridges, almost smooth. Upper edge of orbit low. Postorbital notch with variable deep, short and narrow, not surpassing one third of the orbital diameter.
Head and body covered by very small odontodes, making fish somewhat smooth. Mature males with small hypertrophied odontodes distributes only on lateral margins of the head and weakly on dorsum of pectoral fin (
Fig. 5
). Snout tip with wide naked area, not reaching last pore of infra-orbital ramus of sensory canal. Snout tip ventraly naked, without odontodes between it and upper lip. Lips well developed and covered by papillae; only one irregular papillae row at anterior most area of the upper lip. Two rows of inconspicuous papillae separating upper and lower lips. Maxillary barbel thin and shorter than orbital diameter. Notch present in lower lip. Teeth bicuspid with lateral cusp smallest than medial. Premaxilla with five (2*), six (1), seven (3) or eight (3) teeth.Dentary with five (2), six (1), seven (1) or eight (5*) teeth. Total number of vertebrae 32. Five ribs attached to vertebrae 7 to 11.
Pectoral-fins rays seven (i,6); fin margin sometimes reaching pelvic-fin origin when adpressed. Pelvic-fin rays six (i,5). Dorsal-fin rays eight (i,7); first ray shorter than head lenght; its origin located dorsal of pelvic-fins base. Anal-fin rays six (i,5). Caudal-fin rays 12 (i,10,i); its distal margin slightly concave; dorsal principal rays longer than ventral rays; in
two
Fig. 5.
Sexual dimorphism and plate distribution on abdomen and ventral region of pectoral girdle of
Rineloricaria maacki
.
ab
: holotype, male, MNRJ 31158, 108.4 mm SL;
c-d
: paratype, female, MHNCI 11457, 113.00 mm SL.
L. F. S. Ingenito, M. S. Ghazzi, L. F. Duboc & V. Abilhoa
363
specimens dorsal unbranched ray slightly elongated, extending distally less than one-third of orbital diameter and not prolonged as filament.
Table 2.
Morphometric data of
Rineloricaria maacki
from middle and lower rio Iguaçu. N = sample size; SD = Standard deviation. Range includes the holotype.
Color in alcohol.
Ground color of dorsal surface light brown with darker small spots or vermiculated lines. Parietosupraocciptal dark brown. Five dark brown transverse bars across body; first on dorsal-fin origin, second on distal margin of dorsal-fin rays, third near vertical line surpassing through tip of anal-fin rays, fourth and fifth over caudal peduncle. Pores of laterosensory system without evident dark chromatophores. Ventral surface of the body pale or yellowish.
Variable |
N |
Holotype |
Low |
High |
Mean |
SD |
Standard length (mm) |
9 |
108.4 |
79.7 |
136.2 |
115.0 |
17.6 |
Percents of standard length |
Head length |
9 |
26.0 |
23.1 |
26.0 |
24.2 |
1.1 |
Predorsal length |
9 |
36.2 |
32.6 |
37.4 |
34.8 |
1.5 |
Dorsal spine length |
9 |
19.4 |
19.0 |
21.0 |
20.0 |
0.7 |
Anal spine length |
9 |
15.1 |
13.9 |
16.8 |
15.5 |
1.0 |
Pectoral spine length |
9 |
17.2 |
14.8 |
19.0 |
17.5 |
1.3 |
Pelvic spine length |
9 |
14.3 |
13.5 |
16.2 |
14.7 |
0.8 |
Upper caudal spine length |
9 |
14.7 |
13.9 |
17.2 |
15.5 |
1.1 |
Lower caudal spine length |
9 |
11.7 |
11.0 |
13.8 |
12.2 |
0.8 |
Thoracic length |
9 |
16.5 |
13.2 |
16.9 |
15.4 |
1.3 |
Abdominal length |
9 |
17.6 |
15.6 |
18.2 |
16.8 |
0.9 |
Cleithral width |
9 |
20.6 |
18.8 |
20.9 |
20.0 |
0.7 |
Body depth at dorsal-fin origin |
9 |
9.4 |
9.4 |
13.0 |
10.7 |
1.2 |
Body width at anal-fin origin |
9 |
12.1 |
11.3 |
12.6 |
12.0 |
0.4 |
Postanal length |
9 |
50.2 |
50.2 |
54.0 |
51.8 |
1.3 |
Percents of head length |
Snout length |
9 |
46.9 |
46.9 |
52.2 |
49.6 |
1.4 |
Orbital diameter |
9 |
21.1 |
19.4 |
21.9 |
21.0 |
0.7 |
Interorbital width |
9 |
23.0 |
23.0 |
26.0 |
24.3 |
0.9 |
Head depth |
9 |
35.5 |
35.5 |
43.9 |
40.0 |
2.7 |
Premaxillary ramus |
9 |
6.7 |
6.3 |
7.7 |
7.0 |
0.5 |
Maxillary barbel length |
9 |
4.0 |
3.4 |
7.0 |
4.5 |
1.2 |
Fins yellowish with interradial skin hyaline and small darkbrown blotches on its rays. Blotches of distal margin of caudal fin very expanded and jointed over interradial skin, forming one bar occupying only its distal third. Caudal fin with darkish base.
Distribution and habitat.
Rineloricaria maacki
is known from middle and lower rio Iguaçu, a tributary of the rio
Paraná
basin (
Fig. 6
). This species inhabits the main channel and 364 Two new species of
Rineloricaria
from the rio Iguaçu basin finding consistent diagnostic characters to describe them. Those two species can only be assigned at present to a generic description of
Rineloricaria lima
, which is taxonomically problematic (see below).
tributaries of rio Iguaçu, which has light brown muddy water with medium to fast flow over a sandy bottom. The habitat has little or no marginal vegetation, mainly formed by grass southern Brazil, and the province of Misiones in Argentina or bushes. (
Maack, 2002
). The ichthyofauna of rio Iguaçu includes about
83 species (
Ingenito
et al
., 2004
; present study) and a high
Etymology.
The specific name
maacki
is given in honor of level of endemism, with a rate of about 75% of exclusive spe- Reinhard Maack, a geologist who made some of the most cies (Zawadzki
et al
., 1999). important contributions to the knowledge of the geology and Reis & Cardoso (2001) were the first authors to report the physiography of the rio Iguaçu basin and Paraná State. presence of species of
Rineloricaria
in the rio Iguaçu basin,
when they cited the presence of one or two undescribed spe-
Discussion
cies. Recent studies conducted by us revealed the existence of four possibly undescribed species of
Rineloricaria
at this
The rio Iguaçu is the last large left-bank tributary of rio basin. Two of those species are
Rineloricaria maacki
and Paraná. Its basin extends through a total area about 72,000
Rineloricaria langei
, which are described here. As for the km
2
occupying the States of Paraná and Santa Catarina in other two undescribed species, we did not have success in
Fig. 6.
Distribution of
Rineloricaria langei
(circle) and
Rineloricaria maacki
(square: holotype; triangles: paratypes) in rio Iguaçu basin. One symbol may represent more than one collecting locality. Vertical bars indicate biogeographic barriers of rio Iguaçu according to
Ingenito
et al.
(2004)
(A: Salto Caiacanga falls; B: Salto Grande falls).
The specimens mentioned by Reis & Cardoso (2001) were not available for examination during the present study. However, information provided by Wolmar B. Wosiacki (MPEG) indicates that the lot MCP 17455 examined by those authors is composed by at least one of the two new species assigned as
Rineloricaria
sp.
aff
.
lima
by us. This species was also cited by Vitule & Abilhoa (2003) for rio Piraquara (a headwater river of the rio Iguaçu basin), and it was part of a series of specimens cited by
Ingenito
et al
. (2004)
for upper Iguaçu basin (MHNCI 9133 and MHNCI 9212). The fishes assigned here to
Rineloricaria
sp.
aff
.
lima
are widely distributed in the river basins rio Piraquara,
rio Negro
and rio da Várzea, and are sympatric to
R. langei
in the rio Iraí. Moreover, comparisons carried out by us with
Rineloricaria
specimens from coastal drainages indicate that
Rineloricaria
sp.
aff
.
lima
seems to be widely distributed along the coastal drainages of
Paraná State
, where it is found with a new species under description by us, which is characterized by having a short body and naked thoracic and abdominal regions.
Rineloricaria lima
, the type species of the genus, was collected by Johann Natterer from “Brazilian rivers” during the 18 years that he lived in
Brazil
(1817-1835) (Riedl-Dorn, 2000; Vanzolini, 2004). The type specimen of
R. lima
has been lost and the original description, which was based on a dry specimen, is poor and characterizes most of species of the genus. With the loss of the type specimen of
R. lima
(
Isbrücker, 1979
)
, and the extensive nature of Natterer’s travels (including the Amazon basin, rio
Paraguay
, rio Paraná, rio Paraíba do Sul, and to the cities of Curitiba (rio Iguaçu) and Paranaguá (coastal Atlantic drainages of Paraná State)), it is not easy to associate any specimen to this name until the designation of a
neotype
, what is beyond the scope of this paper.
The absence of ventral plates observed in
R. maacki
is widely variable among loricarids, but among species of
Rineloricaria
sensu lato
this character is restricted to species from the rio Paraná basin (
R. latirostris
,
R. maacki
), rio
Uruguay
(
R. misionera
,
R. setepovos
,
R. anhaguapitan
,
R. reisi
,
R. capitonia
, and
R. tropeira
) and coastal drainages from southeastern and southern
Brazil
(
R. aequalicuspis
,
R. maquinensis
,
R. malabarbai
,
R. baliola
,
R. microlepidogaster
, and an undescribed species from
Rio de Janeiro State
). This character is not exclusive to
Rineloricaria
but can be an indicative of common ancestry between some species from geographical range cited above, as suggested by
Ghazzi (2008)
, and proposed by
Isbrücker
et al
. (2001)
,
Ferraris (2007)
, and Rodriguez & Reis (2008). However, such a hypothesis requires a phylogenetic analysis of the members of
Rineloricaria
, what is also beyond the scope of the present study. The distribution of
Rineloricaria
species
having a naked ventral area may also indicate close biogeographic relationship among
Paraná
and coastal Atlantic drainages through rio Iguaçu, that strengthens the hypotheses of
Ingenito
et al
. (2004)
and Torres
et al.
(2008). Such hypotheses also may explain the morphological similarities among
R. langei
and
R. quadrensis
.
The species herein described do not corroborate the statement proposed by Rodriguez & Reis (2008), who recognized two ecomorphological groups of
Rineloricaria
inhabiting sandy or rocky habitats. Both
R. langei
and
R. maacki
inhabit mostly sandy environments. However, the two new species have the naked area of the tip of snout not reaching the most anterior pore of the infraorbital ramus of sensory canal, which was reported to be a characteristic of the “rocky group” according to Rodriguez & Reis (2008). Such incongruence also occurs in some of the species assigned by those authors to the “sandy group” (
e. g.
R. kronei
,
R. misionera
,
R. quadrensis
,
R. steindachneri
, and
R. strigilata
). Moreover, the presence of the mid-dorsal series of lateral plates in
R. maacki
, a character of the “rocky group”, also contradicts those authors’ statement. The variation evidenced here may indicate that such characters are not informative to distinguish the “sandy” and “rocky” species groups, or that the morphological characters proposed by Rodriguez & Reis (2008) are not associated to specific habitats.