A new species of Jupiaba Zanata, 1997 (Ostariophysi, Characiformes, Characidae) from the rio Tocantins drainage, Brazil
Author
Pereira, Thiago N. A.
Author
Lucinda, Paulo H. F.
text
Zootaxa
2007
1614
53
60
journal article
10.5281/zenodo.179050
02a19ce7-2cdd-4ccc-a4c8-2294a6cc6a98
1175-5326
179050
Jupiaba elassonaktis
,
new species
(
Figs. 1
and
2
,
Table 1
)
Holotype
. (
Fig. 1
).
MCP
41465, 34.5 mm SL, Peixe, rio Tocantins downstream UHE Peixe-Angical, approximately
12°15’S
48°23’W
, Tocantins,
Brazil
,
16 Feb 2007
, NEAMB-UFT.
Paratypes
. All collected by NEAMB-UFT staff. All specimens are from
Brazil
, Tocantins state, Rio Tocantins:
UNT
5568, 8, 24.0–28.4 mm SL, Porto Nacional, rio Tocantins,
10°43’15’’S
48°25’14’’W
,
28 Mar 2005
.
UNT
5569, 19, 20.7–29.5 mm SL, Brejinho do Nazaré, rio Crixás, approximately
11°3’S
48°38’W
,
1 Oct 2003
.
UNT
5573, 1, 35.0 mm SL, Paranã, rio Tocantins, fazenda Traçadal, approximately
16°29’S
48°12’W
,
21 Jul 2005
.
UNT
5575, 1 c&s, 30.9 mm SL, Pedro Afonso, rio Tocantins next to the confluence of rio Sono, aproximately
8°59’S
48°10’W
,
7 Oct 2001
.
UNT
5576, 3, 19.9–32.5 mm SL, Ipueiras, rio Tocantins next to the confluence of rio Manuel Alves, approximately
11°19’S
48°28’W
,
28 Mar 2005
.
UNT
5577, 3, 27.3–29.5 mm SL, Tupirama, rio Tocantins next to the confluence with the rio Tranqueira, approximately
8°45’S
48°8’W
,
7 Oct 2003
.
UNT
5578, 1, 26.5 mm SL, Brejinho de Nazaré, lagoa Pedra do Santo, approximately
11°1’S
48°34’W
,
2 Oct 2003
.
UNT
5579, 1, 26.1 mm SL, Itaguatins, rio Tocantins next to the confluence with the rio São Domingos, approximately
5°43’S
47°30’W
,
8 May 2004
.
MCP
41466, 20, 32.1–36.0, and
UNT
7610, 132, 6 c&s, 32.7–40.3 mm SL, collected with the
holotype
.
Diagnosis
.
Jupiaba elassonaktis
is distinguished from
J
.
acanthogaster
,
J.
atypindi
,
J.
keithi
,
J.
maroniensis
,
J.
meunieri
,
J.
minor
,
J.
pinnata
, and
J
.
poekotero
by the medial cusps of premaxillary teeth much larger than remaining cusps (vs. cusps similar in size to each other) and by dentary teeth decreasing abruptly in size from the fifth tooth backwards (vs. decreasing gradually).
Jupiaba elassonaktis
is distinguished from
J. abramoides
,
J. anteroides
,
J. apenima
,
J. asymmetrica
,
J. pirana
,
J. poranga
,
J. yarina
,
and
J. zonata
by the lower number of scales on lateral line (33–39 vs. 40–66, respectively).
Jupiaba elassonaktis
is distinguished from
J
.
ocellata
by the first dorsal- and anal-fin rays not prolonged by an elongate filament (vs. prolonged by an elongate filament) and from
J
.
mucronata
by the presence of a vertically elongate humeral spot (vs. humeral spot horizontally elongate). The number of scales series above lateral line distinguishes
J
.
elassonaktis
from
J
.
polylepis
,
J
.
potaroensis
, and
J
.
zonata
(5–7 vs. 8–11, respectively). The number of pectoral-fin rays distinguishes
J
.
elassonaktis
from
J
.
essequibensis
and
J
.
scologaster
(9–11 vs. 13–16, respectively).
Jupiaba elassonaktis
is also distinguished from
J
.
essequibensis
and
J
.
scologaster
by the incomplete series of median predorsal scales (vs. complete in later species). Futhermore,
J. elassonaktis
is also distinguished from
J
.
polylepis
and
J
.
essequibensis
by the number of humeral spots.
Jupiaba elassonaktis
possesses two humeral spots. First humeral spot is large and vertically elongate located at fifth and sixth scales of lateral line and the second humeral spot very diffuse.
Jupiaba polylepis
and
J
.
essequibensis
exhibit only one humeral spot (surrounded by a light area and located on sixth to nineth lateral line scales in
J. polylepis
).
Description
. Morphometric data summarized in
Table 1
. Body compressed and somewhat deep; greatest body depth at base of first dorsal-fin ray. Dorsal head profile straight or slightly concave. Profile convex to nearly straight from supraocciptal tip to base of last dorsal-fin ray, and straight towards adipose-fin origin. Anterior portion of ventral profile of head oblique. Posterior portion of ventral profile of head convex. Ventral body profile convex from pectoral-fin origin to pelvic-fin origin, and straight to slightly concave towards anal-fin origin. Body profile along anal-fin base posterodorsally slanted. Caudal peduncle nearly straight to slightly concave along dorsal and ventral margins. Snout rounded from margin of upper lip to vertical through anterior nostrils. Mouth terminal. Distal tip of maxilla anterior to vertical through center of orbit. Anterodorsal border of maxilla straight and posterodorsal border slightly concave. Anteroventral border straight and posteroventral borders convex. Maxilla slightly widened posteriorly.
FIGURE 1.
Jupiaba elassonaktis
,
holotype, 34.5 mm SL, MCP 41465, Brazil, Tocantins, Peixe, rio Tocantins downstream UHE Peixe-Angical.
Two tooth rows on premaxilla. Outer row with three pentacuspid teeth with central cusp longer. Inner row with five teeth, gradually decreasing in length from first to third teeth; all teeth with seven cusps, except last hexacuspidate tooth. First tooth with third cusp twice or three times longer and broader than other cusps. Second, third, and fourth teeth with central cusp twice or three times longer and broader than other cusps. Fifth tooth with fourth cusp twice or three times longer and broader than other cusps. Maxilla with two, three or four teeth; first and second teeth tricuspid, tetracuspid or pentacuspid; third teeth truncate, conical or tricuspid; fourth teeth conical. Five anteriormost dentary teeth larger than remaining teeth. First tooth heptacuspid; Second to fourth teeth with six cusps, followed by one truncate medium-sized tooth, and seven tricuspid teeth; central cusp in all teeth two to three times longer and broader than other cusps. All cusp tips slightly curved posteriorly.
Dorsal-fin rays ii, 8[20], 9 [21], 10[5] (n = 46; mean = 8.7); first unbranched ray approximately one-half length of second ray. Dorsal-fin origin located anterior to middle of SL and in same vertical through pelvic-fin origin. Adipose-fin located approximately at vertical through insertion of base of 17th–19th anal-fin rays. Anal-fin rays iii–iv, 18[7], 19[12], 20[14], 21[11], 22[3] (n = 46; mean = 19.8). Anal-fin profile concave. Anal fin origin anterior to vertical through base of last dorsal-fin ray. Pectoral-fin rays i, 9[1], 10[20], 11[25] (n = 46; mean = 10.5). Pectoral-fin tip not reaching pelvic-fin origin. Pelvic-fin rays i, 7 (n = 46). Pelvic-fin origin located anterior to vertical through dorsal-fin origin. Pelvic bone modified into strong spine. Anterior tip of two pelvic bones diverging widely and usually exserted from body wall. Dorsal procurrent rays 11 [1]. Ventral procurrent rays 9 [1]. Scales cycloid, moderately large. Lateral line complete. Scales in longitudinal series 33[4], 34[16], 35[15], 36[4], 37[1], 39[1] (n = 41; mean = 34.7). Scale rows between dorsal-fin origin and lateral line 5[4], 6[12], 7[28] (n = 44; mean = 6.5); scale rows between lateral line and pelvic fin origin 4[4], 5[38], 6[2] (n = 44; mean = 5.0). Precaudal vertebrae 15 [1], 16 [1]; caudal vertebrae 19 [2]; total vertebrae 34 [1], 35 [1]; supraneurals 4 [1], 5[1]. Gill-rakers 7+1/8 [2].
TABLE 1.
Morphometric and meristic data for types series
Jupiaba elassonaktis
.
Low and high values does not include holotype (H); n = number of specimens.
Character |
H |
n |
low |
high |
mean |
Standard Length (mm) |
34.5 |
47 |
22.5 |
37.9 |
30.8 |
Percents of SL |
Head Length |
24.1 |
47 |
22.8 |
29.8 |
25.7 |
Head depth |
25.2 |
47 |
17.5 |
25.9 |
22.8 |
Body depth |
38.8 |
47 |
25.8 |
39.8 |
32.4 |
Caudal peduncle length |
9.6 |
47 |
6.8 |
11.3 |
9.4 |
Snout to dorsal-fin origin |
46.1 |
47 |
40.6 |
53.9 |
46.3 |
Snout to adipose-fin origin |
82.6 |
47 |
82.2 |
84.3 |
83.2 |
Snout to anal-fin origin |
58.8 |
47 |
51.3 |
67.0 |
58.8 |
Snout to pelvic-fin origin |
46.7 |
47 |
44.1 |
58.8 |
49.1 |
Snout to pectoral-fin origin |
25.8 |
47 |
23.9 |
31.8 |
28.3 |
Dorsal-fin to caudal peduncle |
58.3 |
47 |
51.6 |
66.8 |
58.0 |
Pelvic-fin to caudal peduncle |
59.7 |
47 |
52.3 |
64.4 |
58.6 |
Anal-fin base length |
34.8 |
47 |
27.7 |
32.7 |
30.2 |
Spine-pelvic bone length |
7.2 |
27 |
5.0 |
12.7 |
8.8 |
Distance between spine-pelvic bones |
5.5 |
27 |
1.3 |
6.9 |
4.5 |
Percents of HL |
Snout length |
25.3 |
47 |
19.4 |
30.3 |
23.4 |
Horizontal eye diameter |
56.6 |
47 |
45.6 |
60.6 |
52.1 |
Least interorbital width |
32.5 |
47 |
22.2 |
36.6 |
29.4 |
Upper jaw length |
36.1 |
47 |
25.8 |
45.8 |
34.2 |
Counts |
Lateral line scales |
33.0 |
41 |
33.0 |
39.0 |
34.7 |
Horizontal scale rows between dorsal-fin and lateral line |
7.0 |
44 |
5.0 |
7.0 |
6.5 |
Horizontal scale rows between lateral line and pelvic-fin |
5.0 |
44 |
4.0 |
6.0 |
5.0 |
Dorsal-fin rays |
9.0 |
46 |
8.0 |
10.0 |
8.7 |
Pectoral-fin rays |
11.0 |
46 |
9.0 |
11.0 |
10.5 |
Pelvic-fin rays |
7.0 |
46 |
7.0 |
7.0 |
7.0 |
Unbranched anal-fin rays |
3.0 |
46 |
3.0 |
4.0 |
3.2 |
Branched anal-fin rays |
21.0 |
46 |
18.0 |
22.0 |
19.8 |
Color in alcohol
. Ground color pale yelow. Head dorsum light gray. Two humeral spots separated by a light area. First humeral spot dark brown large and vertically elongate, trespassing upon fifth and sixth lateralline scales and extending over eight or nine horizontal series of scales, including lateral line; center of first humeral spot forming a circular darker spot inside. Second humeral spot very diffuse, trespassing upon ninth and tenth lateral-line scales and extending over eight to ten horizontal series of scales, including lateral line. Second humeral spot not visible in some specimens. Flanks with silvery narrow stripe extending from posterior opercular border to caudal spot. Patch of black chromatophores on caudal peduncle continued by black spot extending over middle caudal-fin rays. Yellow pigmentation on base of outer edge of caudal-fin rays. Remaining fins lacking distinctive patches of pigmentation (
Fig. 1
).
Sexual dimorphism
. No apparent sexual dimorphism was observed.
Etymology
. The specific epithet
elassonaktis
, from the Greek
elasson
, meaning few, and
aktis
, meaning rays, is in allusion to the small number of anal-fin rays.
Distribution
.
Jupiaba elassonaktis
is known from medium and upper portions of rio Tocantins drainage,
Brazil
(
Fig. 2
).