Systematics of Spintherobolus (Teleostei: Characidae: Cheirodontinae) from eastern Brazil
Author
Weitzman, Stanley H.
Division of Fishes, Department of Vertebrate Zoology, MRC- 159, Smithsonian Institution, Washington D. C. 20560, USA.
Author
Malabarba, Luiz R.
Laboratório de Ictiologia, Museu de Ciências e Tecnologia, Pontifícia Universidade Católica do Rio Grande do Sul, Av. Ipiranga, 6681, CEP 90619 - 900, Porto Alegre, RS, Brazil, and Departamento de Zoologia, IB, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil.
text
Ichthyol. Explor. Freshwaters
1999
1999-01-01
10
1
1
43
journal article
10.5281/zenodo.10881992
0936-9902
10881992
DB264AEA-C4EC-48B7-BE35-56761CA13225
Spintherobolus
broccae
Myers
(
Figs. 2
,
32-35
)
Spintherobolus
broccae
Myers, 1925: 143
,
2 figs. (new species description,
type locality: hills behind
Rio de Janeiro
,
holotype
:
CM 7979a
(now
FMNH 58863
),
one
paratype
:
CM 7980a
, five additional spms in author’s collection, # 56, three of these are
USNM 92959
, but 1 spm missing; see also
CAS-SU 24073
below)
Specimens examined.
USNM 92959
,
2 males
,
paratypes
, 20.0-
20.3 mm
SL; near
Rio de Janeiro
(city),
Rio de Janeiro
,
Brazil
;
1924
,
R. Brocca
.
-
CAS-SU 24073
,
1 male
,
20.3 m
SL;
paratype
;
Brazil
,
Rio de Janeiro
, near
Rio de Janeiro
;
1924
;
R. Brocca
&
Salathe
, 1924.
-
USNM 342062
,
1 male
,
19.2 mm
SL,
3 females
,
21.5-22.1 mm
SL;
5 km
East
of
Sampaio Correa
,
Saquarema
;
27 Nov 1979
,
C. Cruz
,
S. Weitzman
et al.
-
USNM 287324
,
1 male
, c&s,
18.2 mm
SL,
2 females
, c&s 18.3- 19.0 mm SL;
13 males
,
17.1-18.9 mm
SL,
27 females
,
17.5-20.9 mm
SL;
MCP 19196
,
4 males
,
17.5-17.9 mm
SL,
3 females
,
17.4-18.9 mm
SL;
rio Macacu
, near town of
Cachoeiras de Macacu
, small tributary about
1 -2 km
from town, highway bridge over stream;
27 Nov 1979
,
C. Cruz
,
S. Weitzman
et al.
-
MNRJ 8796
,
3 males
,
18.1 - 18.4 mm
SL,
3 females
, 18.0-
18.5 mm
SL,
6 immature
,
13.6-17.4 mm
SL; swamp or marshy area near
Imbarié
,
Baixada Fluminense
;
4 Aug 1954
,
L. Travassos
et al.
-
MNRJ 6264
,
62
, adults + immature,
14.6-18.8 mm
SL; old road to
Petrópolis
, about
1-2 km
from new road to Petrópolis,
Raiz da Serra
,
Rio de Janeiro
;
28 Sep 1942
,
L. Travassos
et al.
-
USNM 342064
,
13 males
,
18.6- 22.4 mm
SL,
10 females
,
20.1 -22.9 mm
SL, 1 (c&s),
19.4 mm
SL;
Estacion Ecologia
,
Universidade Federal Rural do Rio de Janeiro
, at
km 43
on the road from
Rio de Janeiro
to
Sao Paulo
;
15 Dec 1972
,
E. Izecksohn
et al.
-
USNM 297997
,
3 females
,
20.8-25.6 mm
SL,
21 young males
,
16.4- 18.8 mm
SL,
214 immature
, 13.0-
20.1 mm
SL; unnamed clear water stream crossing road
SP-98
at
km 94
, northwest of
Bertioga
;
23 Feb 1988
,
R. M. C. Castro
.
Fig. 34.
Spintherobolus
broccae,
USNM 92959, paratype, adult male 20.3 mm SL, Brazil, vicinity of Rio de Janeiro.
Fig. 35.
Spintherobolus
broccae,
USNM 297997, adult female, SL uncertain, Brazil, S ã o Paulo, Bertioga.
Diagnosis. This miniature species lacks infraor bital bone 3. The other miniature species,
S
.
ankoseion
and
S
.
leptoura,
as well as the non-miniature
S
.
papilliferus
have the third infraorbital bone well ossified and, in addition, have significantly lower anal-fin ray counts (
Fig. 20
) and ventral procurrent caudal-fin ray counts (
Fig. 23
). Although statistically significant, there is overlap in these counts (see counts given below), especially in the ventral procurrent caudal-fin ray count, and species determination using these counts must be made by examining population samples, not individual specimens. However, specimens bearing overlapping anal-fin ray counts are uncommon.
Table 4.Morphometriesof
Spintherobolus broccae
.
Table includes measurementsofspecimens from USNM USNM 342062, USNM342064and MCP19196.
males |
females |
n |
low |
high |
mean |
n |
low |
high |
mean |
Standard length [mm] |
31 |
17.1 |
22.4 |
18.8 |
40 |
17.5 |
22.9 |
19.8 |
Percentage of standard length |
Snout to anal-fin origin |
31 |
55.9 |
61.5 |
59.7 |
40 |
57.8 |
63.9 |
60.5 |
Snout to dorsal-fin origin |
31 |
51.3 |
59.5 |
56.2 |
40 |
52.6 |
60.6 |
55.7 |
Snout to pelvic-fin origin |
31 |
36.2 |
44.7 |
42.2 |
40 |
39.8 |
44.7 |
42.1 |
Dorsal-fin base length |
31 |
9.0 |
14.0 |
10.8 |
40 |
9.1 |
12.0 |
11.0 |
Anal-fin base length |
31 |
18.8 |
26.7 |
23.4 |
40 |
19.9 |
26.5 |
23.7 |
Caudal peduncle length |
31 |
12.4 |
19.1 |
15.7 |
40 |
13.1 |
17.7 |
15.4 |
Caudal peduncle depth |
31 |
12.6 |
15.1 |
13.8 |
40 |
11.2 |
14.9 |
13.1 |
Depth at dorsal-fin origin |
31 |
29.2 |
32.8 |
30.5 |
40 |
28.1 |
35.1 |
30.8 |
Dorsal-fin length |
31 |
22.4 |
29.9 |
26.9 |
39 |
22.1 |
30.3 |
26.1 |
Pelvic-fin length |
31 |
16.4 |
20.7 |
18.4 |
38 |
13.5 |
19.5 |
16.9 |
Pectoral-fin length |
29 |
15.2 |
18.7 |
16.9 |
38 |
12.9 |
18.3 |
15.6 |
Bony head length |
31 |
25.4 |
30.4 |
28.6 |
38 |
25.6 |
30.3 |
28.3 |
Percentage of head length |
Snout length |
31 |
17.0 |
23.6 |
20.3 |
39 |
17.6 |
21.8 |
19.9 |
Upper jaw length |
31 |
17.3 |
23.6 |
21.0 |
39 |
17.2 |
25.0 |
21.6 |
Horizontal eye diameter |
31 |
26.3 |
32.7 |
29.1 |
33 |
24.5 |
32.1 |
28.3 |
Least interorbital width |
31 |
26.8 |
34.6 |
29.7 |
33 |
25.0 |
30.8 |
28.1 |
(18, state 2) Infraorbital 3 absent. This is an autapomorphy for
S. broccae
.
See apomorphy 18 for a discussion of infraorbital loss in species of
Spintherobolus
.
The anal-fin ray count for
S. broccae
is 13-16, x = 14.1 versus 11 -14, 12.6 for both
S. ankoseion
and
S. leptoura
.
The ventral procurrent caudal-fin ray count for
S.
broccae
is 14-17, x = 15.4, versus 12-16, x = 14.0 for
S.
ankoseion
and 13-15, x = 14.1 for
S.
leptoura.
These relatively high counts for
S. broccae
relative to all other species of
Spintherobolus
appears autapomorphic for this species.
Description. Morphometric data are summarized in
Table 4
. Body compressed, moderately elongate. Predorsal body profile slightly convex. Body profile along dorsal-fin base posteroventrally inclined, becoming straight or slightly convex between dorsal and caudal fins in females and nearly straight to slightly convex in males. Ventral profile convex from anterior tip of mandible to pelvic-fin origin. Belly profile slightly convex between pelvic-fin and anal-fin origin in females, slightly concave in males. Body profile along anal-fin base concave in females; slightly convex at anterior anal-fin lobe of males and concave along posterior short finned section Ventral profile of caudal peduncle concave i females. Keel formedby prominent ventral pro current caudal-fin rays of males makes ventra profile of caudal peduncle nearly straight bu inclined ventrally in a posterior direction.
Snout short, shorter than eye diameter. Moutl terminal, gape angled posteroventrally; maxil short, not reaching line drawn vertically throug anterior margin of eye.
Dorsal-fin rays, ii,8-9 (x = 8.9, n = 28). Dorsal fin origin behind midbody. Adipose fin absent
Anal-fin rays iii-iv,13-16 (unbranched rays x 3.1, n = 88; branched rays x = 14.1, n = 90) Anterior lobe of anal fin of males rounded, long er than posterior lobe, concave. Anal fin in fe males deeply concave, decreasing in size from posterior unbranched ray to sixth branched ray following rays all of equal size. Anal-fin origin a vertical line drawn through origin of most poste rior dorsal-fin ray in females and at vertical line drawn through middle of dorsal-fin base in males Hooks in anal-fin rays rare among examine males. When present, hooks much reduced in size, found on posterior face of two to six bon segments of posterior branch of first and some times second branched rays. When present, each ray segment bears two to three hooks on each side. Anal-fin rays one through five in males large, second to fourth branched rays more than five times thicker in sagittal dimension than following rays. These large rays with a process on anteroproximal face of each lepidotrich, these being projections of rays two through four, each inserted between lepidotrichia of next anterior ray. Each bony ray segment of posterior branch of branched rays two through four and sometimes also the first and fifth rays, not relatively square like other branches of same ray, but with their posteroventral angle acute and elongate, angled towards distal tip of that fin ray. Segments ofbranched fin rays two and four progressively fused to each other.
Pectoral-fin rays i,8-10 (x = 8.6, n = 36). Posterior tip of longest pectoral-fin rays extending beyond pelvic-fin origin in both males and females. Pelvic-fin rays i,
5 in
all counted specimens (n = 36). Tip of largest ray reaching to or beyond anal-fin origin of males, but not reaching that fin in females. Pelvic-fin rays of males with hooks on unbranched ray and 2 or 3 branched rays, 2 each bone segment. Hooks on ventromedial face and along all length of unbranched to second branched ray and along half length of third branched ray.
Principal caudal-fin rays count usually 10/ 9 (
one specimen
10 / 10 and
one specimen
9 / 9, n = 85). Dorsal procurrent caudal-fin rays 9-13 (x = 11.0, n = 86). Ventral procurrent caudal-fin rays 14-17 (x = 15.4, n = 89). Ventral procurrent caudal-fin rays of males large, well-developed, with their proximal tips fused, slab shaped and expanded in sagittal plane. Four to five most posterior caudal vertebrae (including posterior ‘half centrum’) supporting principal caudal-fin rays and procurrent rays, with enlarged and modified hemal spines. Those elements anterior to the hemal spine of antepenultimate vertebra fused to each other and with lateral bony projections between muscles and skin. Anteriormost ventral caudal procurrent rays with proximal tips absent or abbreviated in length.
Scales cycloid. Lateral line with 2-4 perforated scales (x = 3.4, n = 34). Scales in a lateral series, 31 -33 (x = 31.8, n = 23). Scale rows between dor sal-fin origin and lateral-line series, 4-6 (x = 5.0, n = 31), and between lateral line and pelvic-fin origin, 4-5 (x = 4.7, n = 31). Scale rows around caudal peduncle,
14 in
all specimens (n = 31). No modified scales on caudal fin. Scale sheath along anal-fin base absent.
Teeth. All jaw teeth with a basal pedicle and laterally expanded conical distal tip. Anterior most dentary teeth tricuspid followed lateroposteriorly by conical teeth. Premaxillary and max illary teeth conical. Premaxillary teeth 5-7, maxillary teeth 5-8 and dentary teeth
5-8 in
four c&s specimens.
Vertebrae 32-34 (x = 33.0, n = 88). Branchiostegal rays
4 in
four cleared and stained specimens, with same attachments as in
S
.
papilliferus.
Color in alcohol. See
Figure 2
,
32-33
for the approximately equivalent preserved color patterns of adult males and females. A discrete lateral body stripe extends from just dorsal to the dorsalmost part of the gill opening to the caudal peduncle where it continues onto the caudal fin as a very solid dark wedge with its apex covering the two middle caudal-fin rays. In the photographs of a male and female, there appears to be a dark humeral spot just posterior to the more dorsal region of the opercular flap. This is not a humeral spot. Instead it is the area of the anterior and posterior pseudotympanums and the black pigment coating the swimbladder is visible through the skin.
The scale borders are covered by a single row of dark chromatophores above the lateral stripe, giving the dorsal part of the body a reticulate pattern. The abdomen and sides ventral to the lateral stripe is pale cream color or yellowish (the color of preserved muscle tissue) and the scale borders are devoid of dark chromatophores. The posterior termination ofthe caudal peduncle, both dorsal and ventral to the lateral stripe, is white, without dark pigment of any kind.
The pectoral and pelvic fins of both sexes are hyaline with a few scattered dark chromatophores, especially on the anterior undivided ray of both fins. The dorsal fin is mostly hyaline except for its anterior dorsal border where the anterior undivided rays and the first branched ray have numerous dark chromatophores. The rays posterior to these dark rays progressively lose the dark chromatophores except distally where the posterior tip of the second and often the third branched rays have many dark chromatophores. The caudal fin is hyaline with a thin scattering of small dark chromatophores over the rays and membranes, especially those of the dorsal parts of the dorsal lobe of the male. The anterior base of the anal-fin is the origin of a second dark, relatively broad stripe which covers the muscular anterior base of the fin and extends posteriorly to almost completely cover the short anal-fin rays that follow the large, elongate, anterior anal-fin lobe. The anterior lobe of the fin, distal to its muscular base, is hyaline except for the distal tip of the first branched ray.
The head is pale brown around the mouth with a scattering of dark chromatophores over the ventral surface of the snout, jaws, and oper cular region. In the photographs (
Figs. 2
,
4
,
32- 33
), the snout region, especially the ventral part of the jaws, is overexposed and the dark chromatophores do not show. The dorsal surface of the snout and the area between the eyes are pale brown, while the dorsum of the cranium and the nape are dark brown. The head area posterior to the eye and extending ventrally from the parietal region to the preopercle and branchiostegal rays is white. The circumorbital region ventral to the eye is dark, with a series of dark chromatophores, giving the impression of a spot ventral to the eye. The opercular region is dark dorsally and pale brown to white below in both sexes.
Color in life. See
Figure 35
of a female, taken immediately after capture, from near Bertioga, São Paulo. Life colors are very much like those in preservative except that the dark stripes are black, the abdominal region bluish white and the two white spots at the posterior termination of the caudal peduncle are yellowish to white. The body is translucent greenish yellow. The black chromatophores anterior, dorsal and posterior to the pseudotympanums are expanded and the area they occupy is black; those posterior to this are somewhat contracted and the lateral stripe remains less dense until approximately the anterior end of the caudal peduncle where the black chromatophores are again expanded and the stripe appears black. The black spot ventral to the eye is quite dark with expanded black chromatophores. The premaxilla and maxilla are black. The dentary is white except for scattered black chromatophores in its anterior region. The relatively hyaline regions of the caudal fins are pale reddish and a bit of this color also occurs on the anterior two branched rays of the anal fin.
Sexual dimorphism. Males and females can be recognized externally by the anal fin-shape; compare
Figures 32
and
33
. The anal fin of the females is deeply concave and divided into a prominent anterior lobe that has a rather straight posterodistal border and a narrow posterior lobe made up of relatively short fin rays. The anal fin of males is very similar except the anterior lobe has a rounded or circular posterior border. Not all males have hooks on the anal fin but all of them have hooks on the pelvic-fin rays and anal-fin rays one through five enlarged. Males have a keel in the ventral profile of the caudal peduncle. This is formed by the ventral procurrent fin rays. The ventral procurrent rays of female are unmodified.
Discussion.
Spintherobolus broccae
was described as a new species by
Myers (1925: 143)
from aquar ium specimens and the species was previously misidentified as
Hasemania
bilineata
Ellis (1911: 1950)
by
Rachow (1924: 601)
.
Meinken (1929
a-b) provided the history of the species discovery and importation.
Myers (1925: 144)
considered
S.
broccae
and
Phoxinopsis typicus
Regan (1907: 262)
possibly generically the same and
Myers (1926: 273)
was apparently convinced of this for, he listed the species as
P. broccae
in his list of tropical fish names published by Innes. However, he had not seen Regan’s
type
of
P. typicus
and the illustrations of the two species,
Regan (1907: 262)
and
Myers (1925: 144
, pl. 10), although not exactly the same, look similar enough so that the distinctness of the species was justifiably questionable, especially since Regan ’ s drawing was a hasty sketch. It wasn’t until
Innes (1935: 130)
, on the advice of G. S. Myers, listed the species as
P. typicus
,
that
S.
broccae
came to be considered a junior synonym of
P. typicus
.
Nearly all subsequent aquarium fish literature considered the species to be
P.
typicus.
Travassos (1953: 512)
recognized the species as
S. broccae
.
Böhlke (1954: 30-31)
tentatively rec ognized
P.
typicus
and
S.
broccae
as distinct species and he included these two nominal species and
S.
papilliferus
in
Phoxinopsis
.
His reasons for doing this were based on information received from G. S. Myers sometime before 1953. According to Böhlke, “Prof. G. S. Myers a number of years ago sent a
paratype
of his
Spintherobolus
broccae
to the late J.R. Norman of the British Museum (Natural History) for comparison with Regan’s
type
of
Phoxinopsis
typicus.
Dr. Myers has informed me that after a point by point comparison ofthe
two specimens
(including the teeth, which are very important characters) Norman concluded that they were specifically identical”. Myers must have sent a
paratype
to Norman soon after publication of the original description because the catalog number of the specimen is
BMNH
1925.10.19.1 (Eschmeyer & Ferraris, pers. comm.). This is corroborated by
Myers (1926: 273)
wherein he used the generic name
Phoxinopsis
rather than
Spintherobolus
.
In 1973 Böhlke wrote to SHW that he examined the
type
of
P. typicus
and found it to be an
Aphyocharax
Günther, 1868
. Later the
holotype
of
P. typicus
was borrowed by SHW and identified as
Aphyocharax
anisitsi
Eigenmann & Kennedy (1903: 517)
. Thus
S. broccae
is not a junior synonym of
P.
typicus,
but
P.
typicus
is a junior synonym of
A.
anisitsi
and
Phoxinopsis
is a junior synonym of
Aphyocharax
.
Spintherobolus broccae
and
A. anisitsi
are very different fishes and it is difficult to understand how Norman confused the two. If young specimens of
A.
anisitsi
are compared with comparable sized adult female specimens of
S. broccae
,
about
18-20 mm
in SL, they appear somewhat similar in body shape and fin position, but not in color and certainly not in their teeth and mouth shapes. The
three paratypes
we have seen of
S. broccae
(
USNM
92959,
CAS
24073) are now faded and have lost their dark markings. If they had lost these when Norman examined his specimen, the
type
of
P.
typicus
and the
paratype
of
S. broccae
would have had no striking color pattern differences. Although both species have relatively elongate and somewhat similar jaw teeth, those of
S. broccae
are more slender. Furthermore the gape of
S.
broccae
is wide and the toothed portions of the dentary and the premaxilla ex tend laterally almost at right angles to the long axis of the head and body. In
A.
anisitsi
the mouth opening is narrow, the snout conical, and the toothed portions of the premaxillae and dentaries are curved posteriorly.
Sarraf (1997: 28)
recorded the principal caudal-fin ray count as i, 18,i. This produces a principal ray count of 20 rather than 19. Yet when we counted the principal caudal-fin rays in figure 8 of Saraaf (1997) we counted 10 / 9 which is equivalent to nearly all of the counts given above in our description of
S. broccae
and would be i,17,i for a total
19 in
Sarraf ’ s method of counting. The dorsal-fin ray count was recorded ii,8 by
Sarraf (1997: 28)
. We found the number to be ii,
9 in
most specimens, and found ii,8 as an unusual count (x = 8.9, n = 28).
Ecological notes.
Myers (1944: 186)
reported specimens from “behind the beach of Sernambetiba” to live in dark-brown swamp waters. SHW has taken this species (
USNM
287324,
MCP
19196) in somewhat brown acid waters of a stream in the forests surrounding the town of Cachoeiras de Macacu, Rio de Janeiro and from clear waters of a stream draining into lagoa Saquarema (
USNM
34206). The area around lagoa Saquarema was at one time at least partly forested, but this is no longer true. Nevertheless,
S.
broccae
has survived in the region. The species appears to be present in somewhat acid waters in relatively lowland areas, in both swamps and slow moving streams, to the north and south of the city of Rio de Janeiro, but only in areas where the streams remain unpolluted.