A taxonomic review of the species of Charax Scopoli, 1777 (Teleostei: Characidae: Characinae) with description of a new species from the rio Negro bearing superficial neuromasts on body scales, Amazon basin, Brazil
Author
Menezes, Naércio A.
Author
de Lucena, Carlos Alberto S.
text
Neotropical Ichthyology
2014
2014-06-30
12
2
193
228
http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1679-62252014000200193&lng=en&tlng=en
journal article
10.1590/1982-0224-20130175
09f66541-18e3-4044-b553-7aab04763396
1982-0224
4638995
2CFAB1CE-D283-483B-8C2B-87D95AEADE70
Charax notulatus
Lucena, 1987
Fig. 21
Charax notulatus
Lucena, 1987: 46
(original description,
type
locality:
Venezuela
, DeltaAmacuro,
río Orinoco
, small cãno near mouth of Caño Soroco). -
Vari
&
Howe
, 1991: 13-14 (listed in
type
catalog). -Oyakawa, 1996: 456 (listed in
type
catalog). -Provenzano
et al
., 1998: 5 (listed in
type
catalog). -
Lucena
, 1989: 104 (in key to species). -
Lucena
&
Menezes
, 2003: 201 (maximum length; distribution).
Diagnosis.
Among congeners
Charax notulatus
differs from
C. apurensis
,
C. macrolepis
,
C. michaeli
,
C. pauciradiatus
,
C. gibbosus
,
C.
niger
, and
C. leticiae
in the orbital diameter (26.1-28.5%
vs.
30.1-38.4% of HL,
Fig. 4
).
Charax notulatus
can be distinguished from
C. caudimaculatus
in the snout length (24.3-26.3%
vs.
20.3-22.8% of HL,
Fig. 5
).
Charax notulatus
differs from
C. hemigrammus
,
C. condei
, and
C. stenopterus
by having the lateral line complete (
vs.
lateral line incomplete), from
C. rupununi
by the number of scales around the caudal peduncle (20-22
vs.
12) and from
C. tectifer
,
C. metae
, and
C. delimai
by having the anal-fin origin always located anterior to the vertical through the dorsal-fin origin (
vs.
anal-fin origin on, the vertical or slightly posterior to, the vertical through the dorsal-fin origin) and ectopterygoid teeth absent (
vs.
ectopterygoid teeth present).
Description.
Morphometrics of examined specimens presented in
Table 12
. Body elongate, moderately large (
53- 79 mm
SL), compressed and moderately deep. Greatest body depth slightly in advance of dorsal-fin origin. Dorsal profile of head and body straight from tip of snout to anterior region of fontanel, slightly concave from that point to base of supraoccipital spine, convex from that point to dorsal-fin origin, nearly straight along dorsal-fin base and from end of dorsal-fin base to caudal peduncle and slightly concave along caudal peduncle. Ventral profile of head and body convex from tip of lower jaw to anal-fin origin, nearly straight along anal-fin base and concave from end of anal-fin base to beginning of procurrent rays. Snout pointed. Lower jaw included in upper jaw when mouth closed. Maxilla extending to about vertical through posterior border of pupil.
Dorsal-fin rays ii, 9 posteriormost ray unbranched.Adipose fin present. Unbranched anal-fin rays iv or v, usually iv, branched rays 43-53, 48.1. Pectoral-fin rays i, 13-16, 14.6. Tips of longest pectoral-fin rays reaching to, or slightly beyond, vertical through anal-fin origin. Pelvic-fin rays i, 7. Tips of longest pelvic-fin rays reaching vertical through bases of fourth and sixth branched anal-fin rays. Principal caudal-fin ray count 10/
9 in
all specimens.
Lateral line complete; perforated scales 58-64, 60.5. Horizontal scale rows from dorsal-fin origin to lateral line 18- 19, 18.1. Horizontal scale rows from pelvic-fin origin to lateral line 10-12, 11.5. Scale rows from anal-fin origin to lateral line 14-17, 15.1. Predorsal scales 46-52, 48.5. Scale rows around caudal peduncle 20-22, 20.7. Scale row along anal-fin base extending for about
2
/
3
of fin base.
Premaxillary with one anterior canine-like tooth followed by a set of smaller conical teeth and another canine-like tooth followed by one or two small conical teeth. Total number of premaxillary teeth 13-15, 14. Maxillary teeth conical, 58-78, 63.6; larger specimens usually with higher counts. Dentary with one canine-like tooth followed by 3-4, 3.6 conical teeth, another canine-like tooth and a posterior row of 28-34, 30.5 conical teeth.
Vertebrae
32 in
one specimen. Gill-rakers on lower limb of first gill-arch 8-9, 8.7. Branchiostegal rays 4; 3 rays originating from anterior ceratohyal and 1 from posterior ceratohyal.
Color in alcohol.
Body pale to light yellow, slightly darker dorsally than on lateral and ventral regions. Body lighter ventrally with scattered dark chromatophores especially posteriorly. Dorsal region of head, snout and tip of lower jaw darker than remainder of head. Dark chromatophores spreading over first, second, between second and third infraorbitals as subocular blotch extending ventrally to ventral border of preopercle. Dark chromatophores scattered over median portion of lower jaw and median portion of maxilla. Scattered dark chromatophores on preopercle, and opercle. Irregularly shaped, vertically elongate, dark humeral blotch extending about 5 to 7 scales horizontally and 5 to 8 scales vertically. Small, oval-shaped, dark caudal blotch on caudal base with dark chromatophores of posterocentral portion extending over bases of median caudal-fin rays. Inconspicuous dark lines of chromatophores forming V-shaped patterns along miosepta of epaxial muscles above lateral line. All fins hyaline with scattered dark chromatophores, more visible on interradial membranes. Anterior portion of first and second unbranched dorsal-fin rays and first unbranched rays of pectoral and pelvic fins darker than remaining rays.
Distribution.
This species occurs in tributaries of the río Orinoco drainage (
Fig. 7
).
Specimens reexamined.
Venezuela
:
USNM 233624
,
5 paratypes
,
65.7-71.5 mm
SL,
Delta do Amacuro
, 111 nautic miles above
Mar de Buoy
, small stream near mouth of
río Socoroco
,
río Orinoco
drainage,
08°35’N
61°42’W
;
USNM 260305
,
1 paratype
,
76 mm
SL,
Guárico
,
5 km
N of RPV 83-4, río
Portuguesa
,
08°14’N
67°35’W
;
USNM 270254
,
3 paratypes
,
70-74 mm
SL,
Monagas
,
Los Castillos
, isolated pond
between Ordoz and Barrancas
, 263 nautical miles from
Sea Buoy
,
08°31’36"N
62°26’42"W
;
MZUSP 28659
,
1 paratype
,
62 mm
SL,
Delta do Amacuro
,
río Guarguapo
, tributary of
río Orinoco. Already
included in
Lucena
(1987)
.