A review of the Cis-Andean species of Hemibrycon Günther (Teleostei: Characiformes: Characidae: Stevardiinae), with description of two new species
Author
Bertaco, Vinicius A.
Author
Malabarba, Luiz R.
text
Neotropical Ichthyology
2010
2010-12-31
8
4
737
737
http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1679-62252010000400005&lng=en&tlng=en
journal article
10.1590/S1679-62252010000400005
1982-0224
5422215
Hemibrycon helleri
Eigenmann, 1927
Fig. 4.
Map of central and northern South America showing geographic distribution of
Hemibrycon beni
(1, solid hexagon),
H. divisorensis
(2, open triangle),
H. helleri
(3, ellipse),
H. huambonicus
(4, solid triangles),
H. jelskii
(5, solid dots),
H. inambari
(6, rectangles),
H. metae
(7, solid squares),
H. mikrostiktos
(8, open square),
H. polyodon
(9, inverted triangle),
H. surinamensis
(10, solid diamonds),
H. taeniurus
(11, Trinidad Island),
H. tridens
(12, open circle). Some symbols represent more than one lot or locality of specimens. 1-12 = type locality of each species.
Figs. 5-6
Hemibrycon helleri
Eigenmann, 1927: 402
(in key), 406 (pl. 96, fig. 2; original description;
type
material;
type
locality: río Comberciato, río Urubamba drainage).
Diagnosis.
Hemibrycon helleri
is distinguished from all congeners, except
H. jelskii
, by the size of humeral spot (over 7-8
vs.
3-6 horizontal series of scales). It differs from
H. jelskii
by the number of branched anal-fin rays (19-23
vs
. 25-30,
Fig. 2
),
742 A review of the Cis-Andean species of
Hemibrycon
and by the number of scales along anal-fin base scale sheath (6-12
vs
. 13-28).
Hemibrycon helleri
is rather similar to
H. inambari
new species
, but can be distinguished by the size of humeral spot (over 7-8
vs.
5-6 horizontal series of scales), number of predorsal scales (16-18
vs.
13-16), and by the total number of vertebrae (41-43
vs.
39-40).
Fig. 5.
Hemibrycon helleri
, ANSP
180775, female, 81.1 mm SL, upper río Ucayali basin, Peru.
Description.
Morphometric data for
H. helleri
summarized in
Table 1
. Largest male
78.6 mm
SL, largest female
81.6 mm
SL. Body compressed and moderately elongate; greatest body depth at vertical through middle length of pectoral fins. Dorsal profile of head straight to slightly convex. Dorsal body profile convex from occipital bone to base of last dorsal-fin ray; straight from this point to adipose-fin origin. Ventral profile of head nearly straight to slightly convex. Ventral body profile convex from pectoral-fin origin to pelvic-fin origin, and straight to slightly convex to anal-fin origin. Body profile along analfin base posterodorsally slanted. Caudal peduncle elongate, nearly straight to slightly concave along dorsal and ventral margins.
Snout rounded from margin of upper lip to vertical through anterior nostrils. Head small. Mouth terminal, mouth slit nearly at horizontal through middle of eye. Maxilla long and slightly curved, aligned at angle of approximately 45º to longitudinal body axis, and its posterior tip extending below orbit, reaching nearly to vertical through center of eye.
Premaxilla with two tooth rows; outer row with 3-5, tricuspid teeth with central cusp slightly longer; inner row with 4 tetra- to pentacuspids teeth, gradually decreasing in length from first to third teeth and last tooth smallest; central cusp twice or three times longer and broader than other cusps. Maxilla fully toothed with 8-14 uni- to tricuspid teeth, with central cusp longer. Three anteriormost dentary teeth larger, with 5 cusps, followed by medium sized tooth with 3 cusps, and 7-9 teeth with 1-3 cusps or conical; central cusp in all teeth two to three times longer and broader than other cusps. Cusp tips slightly curved posteriorly and lingually (
Fig. 6
).
Dorsal-fin rays ii,8 (n = 33); first unbranched ray approximately one-half length of second ray. Dorsal-fin origin located posterior to middle of SL and posterior to vertical through pelvic-fin origin. Profile of distal margin of dorsal fin nearly straight to slightly concave. Males with bony hooks in distal one-third of first branched rays. Adipose-fin located at vertical through insertion of last or posterior to last anal-fin ray. Analfin rays ii-v,19-23 (mode = 21, n = 37,
Fig. 2
). Anal-fin profile slightly convex in males and nearly straight in females. Analfin origin approximately at vertical through insertion in the last dorsal fin rays. Anal-fin rays of males bearing one pair of small bony hooks along posterolateral border of each segment of lepidotrichia, along last unbranched ray and twelfth to sixteenth branched rays. One male
paratype
had bony hooks in all analfin branched rays. Hooks usually located along posteriormost branch and distal
1
/
2
to
2
/
3
of each ray. Pectoral-fin rays i,10-11
Fig. 6.
Hemibrycon helleri
,ANSP
180775, female, 66.6 mm SL. Scanning electron micrograph of right side upper and lower jaws. Scale bar = 1 mm.
V. A. Bertaco & L. R. Malabarba
743
(mode = 10, n = 27). Pectoral-fin tip reaching pelvic-fin origin in males. Males with bony hooks on distal portion of unbranched and all branched rays. Pelvic-fin rays i,6,i (n = 30). Pelvic-fin origin located 4-5 predorsal scales anterior to vertical through dorsal-fin origin. Pelvic fin of males usually bearing one small bony hook per segment of lepidotrichia along ventromedial border of fourth to eighth branched rays. Caudal fin forked with 19 principal rays without bony hooks (n = 30); lobes similar in size. Caudal-fin base with a few scales in half-length, followed by one large scale in each lobe. Dorsal procurrent rays 8-10 and ventral procurrent rays 9-10 (n = 12).
Scales cycloid, moderately large. Lateral line complete with 42-45 (mode = 42, n = 23,
Fig. 3
). Scale rows between dorsalfin origin and lateral line 7-8 (mode = 8, n = 35); scale rows between lateral line and pelvic-fin origin 5-6 (mode = 6, n = 35). Predorsal scales 15-18, arranged in regular series (mode =16,n = 34). Scales rows around caudal peduncle 16-18 (mode = 16, n = 27). Axillary scale on pelvic-fin origin extends posteriorly covering 2-3 scales. Scale sheath along anal-fin base with 6-12 scales in single series, extending to base of most anterior branched rays.
Precaudal vertebrae 19-21; caudal vertebrae 22-23; total vertebrae 41-43 (n = 12). Supraneurals 6-7 (n = 12). Gill rakers on upper limb of outer gill arch 6-7, and on lower limb 10-11 (n = 11).
Color in alcohol.
Type
material discolored. Color based on the non-type specimens. General ground body color yellowish. Dorsal portion of head and body with dense concentration of black chromatophores. Dorsolateral portion of head and body with scattered black chromatophores. Midlateral body silvery. One large and vertical black humeral spot, located over fourth to sixth lateral line scales and extending over 7-8 horizontal series of scales, including lateral line. Midlateral dark stripe extending from humeral region to middle caudal-fin rays, broad in the caudal peduncle. Abdominal region almost devoid of black chromatophores. Adipose fin densely black pigmented. Dorsal and caudal fin with black pigmentation diffuse and anal fin with small black chromatophores along its border forming narrow stripe. Pectoral and pelvic fins hyaline (
Fig. 5
).
Sexual dimorphism.
Males of
Hemibrycon helleri
are easily recognized by the presence of bony hooks on the dorsal-, pectoral-, anal- and pelvic-fin rays. Males and females also slightly differ in body depth (
Table 1
), and in anal-fin shape, which is slightly convex in males and nearly straight in females. Mature males with gill gland on first gill arch, covering the first branchial filaments (
Fig. 7
).
Distribution.
Hemibrycon helleri
is known from río Comberciato, and río Urubamba, upper
río Ucayali
drainage,
Cusco
,
Peru
(
Fig. 4
).
Remarks.
Eigenmann (1927: 406) described
Hemibrycon helleri
and designated the
holotype
as “13565 Type” [
MCZ 31565
, the catalog number mistakely cited in the original description] and
17 paratypes
(CM 7439, IU 13754) from río Comberciato,
Peru
. Later, Eigenmann & Allen (1942: 216) listed the type material but did not provided the catalog number for types of
H
.
helleri
, but listed
18 type
specimens along with their lengths, and type locality. Böhlke (1953) in his catalog of types from Stanford University did not list types of
H
.
helleri
. Ibarra & Stewart (1987: 43) listed
three paratypes
of
H
.
helleri
but did not provide the catalog number of FMNH specimens.Eschmeyer (1998: 717) listed two possible lots as
holotype
, “?
MCZ 31565
” (1) or
MCZ 30980
(1), and the following lots as
paratypes
:
CAS 44354
[ex IU 13754] (5) and FMNH 58439 (3), followed posteriorly by
Lima
et al
. (2003: 129)
; there are
8 paratypes
missing.
According to Eigenmann (1927) the
holotype
has
100 mm
of size [total length - TL]. The specimen from
MCZ 31565
measures
78.9 mm
SL and
94.9 mm
TL and the specimen from
MCZ 30980
has
81.1 mm
SL and
98.9 mm
TL. Although the specimen from
MCZ 30980
is larger and more close to the body size of the
holotype
mentioned by Eigenmann (
100 mm
TL), the specimen corresponding to the original catalog number referred as the
holotype
MCZ 31565
(mistyped 13565) has the same number of branched anal-fin rays of the specimen illustrated as the
holotype
in the figure 2 by Eigenmann (1927, plate 96), 23
vs
. 22 branched anal-fin rays on specimen of lot
MCZ 30980
, and so we consider that the specimen available as
MCZ 31565
is actually the
holotype
. Based on data and fish images taken from the lots
MCZ 30980
(1), and
MCZ 30981
(7) we can confirm that these specimens are part of the missing type series of
H
.
helleri
. The specimen listed as nontype by Eigenmann (1927: 406;
CAS 44355
, ex IU 17611) from río Crisnejas,
Peru
is actually a specimen of
H
.
huambonicus
.
Material examined.
Holotype
.
MCZ
31565
, female (x-ray),
78.9 mm
SL,
río Comberciato
, a small tributary of middle
río Urubamba
,
30 miles
above the
Pongo
de Mainique
,
Cusco
,
Peru
,
1,800 ft.
elev.,
ca
.
12º28’S
73º07’W
, 1910-1915,
E. Heller
(Yale-National Geographic Expedition)
.
Paratypes
.
CAS
44354
,
5
,
39.6
-72.0 mm SL
,
FMNH 58439
,
3
(x-ray),
36.4-78.5 mm
SL
,
MCZ
30980
,
1
(x-ray),
81.1 mm
SL
,
MCZ
30981
,
8
(x-ray),
46.1-79.2 mm
SL, collected with the
holotype
.
Non-type
specimens.
Peru
,
Cusco
,
río Urubamba
drainage
:
ANSP 180775
,
4
(1 c&s),
53.3-81.1 mm
SL, quebrada
Rosaríomayo
, west of
Quelluono
on road to
Kiteni
,
12º46’28”S
72º39’06”W
,
19 Jul 2004
.
ANSP 180777
,
2
,
20.4-72.4 mm
SL,
río Amaybamba
, southeast of
Quillabamba
on road to
Ollantaytambo
,
12º59’55”S
72º31’24”W
,
17 Jul 2004
.
ANSP 180780
,
1
,
23.5 mm
SL,
Yanayaku Grande
, tributary of
río Urubamba
, southeast of
Quillabamba
on road to
Ollantaytambo
,
12º59’49”S
72º32’06”W
,
17 Jul 2004
.
CAS
70077
,
15
,
27.5-81.5 mm
SL, río
de Santa Ana
, creek entering middle
río Urubamba
at
ca
.
3000-3400 ft.
elev., the farthest point reached by the
Eigenmann’s
on
río Urubamba
,
ca
.
12º52’S
72º43’W
,
15 Nov 1918
.