Revision of the South American freshwater fish genus Laemolyta Cope, 1872 (Ostariophysi: Characiformes: Anostomidae)
Author
Mautari, Kelly Cristina
Author
Menezes, Naércio Aquino
text
Neotropical Ichthyology
2006
2006-03-31
4
1
27
44
http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1679-62252006000100002&lng=en&tlng=en
journal article
10.1590/S1679-62252006000100002
1982-0224
5418442
22071950-40B5-4151-AB3C-D6AE6A2607E9
Laemolyta proxima
(
Garman, 1890
)
Fig. 19
Anostomus
(
Schizodontopsis
)
proximus
Garman, 1890: 19
[original description,
type
locality: Villa Bella and Ueranduba];
Borodin, 1931:47
[diagnosis, MCZ material listed];
Eschmeyer, 1998: 1386
[catalog].
Laemolyta proximus
:
Eigenmann & Eigenmann, 1891:50
[listed].
Anostomus proximus
:
Eigenmann, 1910: 425
[listed].
Laemolyta proxima
:
Myers, 1950: 197
[diagnosis, typelocality];
Fowler, 1950: 209
[synonymy list, distribution];
Géry, 1964: 466
[identification key], 1974:155–157, 159 [diagnosis, description, identification key]; Garavello & Britski, 2003: 73 [catalog].
Anostomus
(
Laemolyta
)
proximus
:
Géry, 1977: 182
[synonymy, identification key, distribution].
Anostomus
(
Schizodontopsis
)
varius
Garman, 1890: 19
, 20 [original description, type-locality: Gurupa, José Fernandes, Lake Hyanuary, Manaos (Manaus), Obydos (Óbidos), Porto do Moz,
rio Negro
];
Ulrey, 1895: 261
[morphological data, color pattern];
Borodin, 1931: 46–47
(diagnosis, MCZ material listed];
Eschmeyer, 1998: 1745
[catalog].
Anostomus varians
[error]:
Eigenmann & Eigenmann, 1891: 425
[listed].
Laemolyta varia
:
Myers, 1950: 197
[diagnosis, type-locality];
Fowler, 1950: 209
[synonymy list, distribution];
Géry, 1964: 466
(identification key]; 1974: 155–157, 159 [diagnosis, description, identification key];
Santos, 1982: 713–739
[ecological data]; Santos & Jegú, 1996: 161, fig. 11, p. 179 [INPA’s material listed, rio Uatumã (Amazon basin)]; Garavello & Britski, 2003: 73 [catalog].
Anostomus varius
: Vari & Howe, 1991: 5
[
type
catalog].
Anostomus
(
Schizodontopsis
)
varius nitens
Garman, 1890: 20
[original description, type-locality:
Iça
];
Borodin, 1931:47
[diagnosis];
Eschmeyer, 1998: 1190
[catalog].
Laemolyta varius nitens
:
Eigenmann & Eigenmann, 1891: 50
[listed].
Anostomus varians
[error]
nitens
:
Eigenmann, 1910: 425
[listed].
Anostomus
(
Schizodontopsis
)
nitens
:
Borodin, 1931: 46–47
[diagnosis, material of MCZ listed)
Laemolyta nitens:
Myers, 1950: 197
[diagnosis, type-locality];
Fowler, 1950: 209
[synonymy list, distribution];
Géry, 1964: 466
[identification key]; 1974:155–157, 159 [diagnosis, description, identification key]; Garavello & Britski, 2003: 73 [catalog].
Anostomus
(
Laemolyta
)
nitens
:
Géry, 1977: 182
[identification key, distribution].
Anostomus nitens
: Vari & Howe, 1991:5
[
type
catalog].
Material examined
.
244 specimens
(
48.1–249.9 mm
SL).
Brazil
.
Amazonas
:
Villa Bella
(
rio Amazonas
at
Parintins
and environs),
27 August 1865
,
L. Agassiz
,
MCZ
19331
,
1 lectotype
(designated herein),
165.3 mm
SL.
Lago José Fernandes
(location unknown, presumably near
Manaus
),
November 1865
,
Maj. J. M. S.
,
MCZ
19378
,
5 paralectotypes
,
75.9–113.1 mm
SL.
Rio Negro
at
Manaus
, 1863,
J. C. Fletcher
,
MCZ 809
,
1 paralectotype
,
160.7 mm
SL.
Lago Hyanuary
(
Paraná
do
Janauari
),
27 October 1865
,
L. Agassiz
,
MCZ
19335
,
4 paralectotypes
,
98.6–188.1 mm
SL.
Içá
,
November
, 1865,
USNM 120242
,
3 paralectotypes
,
82.9–92.5 mm
SL.
José Fernandes
, 1867,
USNM 120398
,
1 paralectotype
.
Mouth
of
rio Ituxi
,
MZUSP 21487
,
2
,
168.7
and
174 mm
SL.
Lagoa Central
, left bank of
rio Negro
, between rivers
Camaraú
and
Apaú
,
MZUSP 21062
,
3
of 4,
81.4–91.4 mm
SL.
Lago Janauacá
,
MZUSP 27898
,
1
,
80.0 mm SL.
Lago Puraquequara
,
rio Amazonas
,
MZUSP 53640
,
4
,
65.6–83.4 mm
SL.
Lago Janauarí
,
MZUSP 62434
,
3
,
76–83.4 mm
SL.
Lago Manacapuru
,
MZUSP 5886
,
1
of
2, 224.5 mm
SL.
Lago Berurí
,
rio Purus
,
MZUSP 6003
,
2
,
170.7
and
178.8 mm
SL.
Rio Negro
near
Manaus
,
MZUSP 6703
,
1
,
86.1 mm
SL.
Rio Madeira
,
25 km
below Nova Olinda
,
MZUSP 6964
,
1
,
95.1 mm
SL.
Rio Canumá
,
MZUSP 7058
,
2
,
170.8
and
188.9 mm
SL.
Paraná
de Urucará
,
Urucará
,
MZUSP 7517
,
3
,
95.6–103.7 mm
SL.
Mouth of Lake José-Açu
,
Parintins
,
MZUSP 7643
,
2
,
99.2–119.9 mm
SL.
Lago Castro
, mouth of
rio Purus
,
MZUSP 20907
,
1, 106.9 mm
SL.
Rio Negro
,
Cantagalo
,
MZUSP 43293
,
1, 228 mm
SL.
Lago Janauacá
, right bank of
rio Solimões
,
MZUSP 21557
,
1, 200.8 mm
SL.
Lago Janauacá
and surroundings,
rio Solimões
,
MZUSP 21693
,
3
,
175.5
–
239.6 mm
SL.
Costa
do
Japão
,
lower rio Japurá
,
Tefé
,
MZUSP 27381
,
1, 101.8 mm
SL,
MZUSP 27382
,
1
,
92 mm
SL.
Rio Tefé
,
Mucurá
,
MZUSP 29186
,
6
,
72.2–97.3 mm
SL,
MZUSP 60185
,
4
of 7, 188.5–
214.4 mm
SL.
Rio Negro
,
Anavilhanas
,
MZUSP 29191
,
2
,
97.9–100.7 mm
SL,
MZUSP 32414
,
1, 169.5 mm
SL,
MZUSP 32415
,
3
,
194.9
–
226.7 mm
SL,
MZUSP 60176
,
1, 172.9 mm
SL,
MZUSP 60185
,
4
of 7, 188.5–
214.4 mm
SL,
MZUSP 60177
,
1, 159.3 mm
SL.
Rio Tefé
,
Aranatuba
,
MZUSP 29187
,
1
of 3, 97 mm SL.
Rio Tefé
, beach at
Vista Escura
,
MZUSP 31426
,
1, 178.4 mm
SL,
MZUSP 32403
,
4
of 14, 169.8–
249.9 mm
SL Rio Tefé
,
Mastro
,
Ressaca
,
MZUSP 32399
,
1, 208.3 mm
SL.
Rio Tefé
, beach at
Jurupari
,
MZUSP 32400
,
5
,
212.6
–
229.5 mm
SL,
MZUSP 61458
,
5
,
201.2
–
230.7
.
Lake
at
Tefé
,
MZUSP 32401
,
8
of 17, 201.3–
239.2 mm
SL.
Rio Tefé
,
Mastro
,
Capim
,
MZUSP 60171
,
2
,
214.6
–
224.7
.
Tefé
, beach at
Jurupari
,
MZUSP 60173
,
1, 212.5 mm
SL.
Rio Tefé
,
Supiã-Pucu
,
MZUSP 60174
,
3
,
205.7
–
231.7 mm
SL.
Rio Tefé
,
Ressaca de Paula
,
MZUSP 60179
,
11
of 23, 162.5–
225.6 mm
SL.
Rio Negro
, junction with
Ararirá
,
MZUSP 60188
,
1, 218 mm
SL,
MZUSP 60189
,
5
,
159.1
–
238.4 mm
SL.
Pará
:
Gurupá
(
rio Amazonas
delta at
Gurupá
),
22 August 1865
,
L. Agassiz
et al
.,
MCZ
19340
,
3 paralectotypes
,
111.5–126.7 mm
SL.
Porto Moz
,
rio Xingu
at
Porto do Moz
,
23 August 1865
,
L. Agassiz
et al
.,
MCZ
19341
,
1 paralectotype
,
175.9 mm
SL.
Rio Amazonas
at
Óbidos
,
November 1865
,
Bento
,
MCZ
19348
,
2 paralectotypes
,
87.8–103.8 mm
SL.
Óbidos
(
rio Amazonas
at
Óbidos
),
December 1865
,
James, W.
& W.
Hunnewell
,
MCZ
19532
,
1 paralectotype
,
58.1 mm
SL.
Rio Tapajós
,
Pimentel
, below mouth of
rio Jamanxim
,
INPA 6906
,
3
,
54.0–
65.6 mm
SL.
Rio Trombetas
, lago
Jacaré
,
Expedição do Departamento de Zoologia
and
Museu Goeldi
,
MZUSP 64066
,
4
,
117.8
–
132.1 mm
SL.
Lago Bernardino
, near
Badajós
,
rio Capim
,
MZUSP 6874
,
1
of
2, 101.1 mm
SL.
Paraná Samuuma
, mouth of
rio Tocantins
,
MZUSP 21249
,
2
,
197
–
200.0 mm SL.
Igarapé Açu
,
Aveiro
,
MZUSP 21360
,
1, 125.3 mm
SL.
Rio Tapajós
,
São Luís
,
MZUSP 21388
,
1
of
2, 191.3 mm
SL.
Rio Tapajós
,
Barreirinha
,
MZUSP 21411
,
1, 178.3 mm
SL.
Rio Tapajós
,
Maloquinha
,
MZUSP 21400
,
2
,
173.3
and
186.1 mm
SL.
Rio Tapajós
, lake in front of
Monte Cristo
,
MZUSP 21414
,
1, 148.4 mm
SL.
Igapó
do lago
Farias
,
rio Trombetas
,
Trombetas Biological Reserve
,
MZUSP 15788
,
1, 202.3 mm
SL,
MZUSP 15960– 61
,
1
200.1 mm
SL.
Rio Xingu
,
Belo Monte
, river channel,
MZUSP 60182
,
5
of 19, 179.5–
194.8 mm
SL,
MZUSP 61640
,
1
of
2, 192.1 mm
SL.
Rio Tapajós
,
between Itaituba and São Luís
,
MZUSP 61640
,
1
of
2, 192.1 mm
SL.
Rio Trombetas
,
20 km
above mouth,
MZUSP 61950
,
1, 145.5 mm
SL.
Roraima
:
rio Branco
,
INPA 14046
,
5
,
74.7– 97.2 mm
SL.
Rio Branco
,
Marará
,
Paraná-Fechada
,
MZUSP 60183
,
2
,
205.2
–
210.6 mm
SL.
Rio Branco
between mouth and
rio Xeriuni
,
MZUSP 61443
,
1, 197.4 mm
SL.
Rio Branco
, beach and
Paraná
at
Marará
,
MZUSP 61642
,
5
,
149.6
–
191.7 mm
SL.
Bolivia
,
Beni
:
río Baures
at mouth on right bank
6 km
SW of Costa Marques
,
AMNH 39987
,
6
,
48.1–143.9 mm
SL.
Río Itenez
,
1 km
downstream (W) of
Costa Marques
, Mamoré-Madeira-Amazon drainage,
UMMZ 204904
,
3
,
69.9–187.7 mm
SL.
Guiana
.
Essequibo
River
,
Rockstone
,
ANSP 137804
,
1, 114.8 mm
SL.
Peru
.
Loreto
:
río Nanay
, well above
Moronacocha
, vicinity of
Iquitos
,
ANSP 137804
,
1, 114.8 mm
SL.
Itaya
,
Ancieta
,
UMMZ 216875
,
1
,
96.7 mm
SL.
Shansho
caño, drainage of
Ampiyacu
,
USNM 175839
,
1, 144.9 mm
SL.
Río Itaya
, main channel and portions below caños,
5 to 20 km
above Belen
,
Iquitos
,
USNM 280741
,
1
,
74 mm
SL.
Río Nanay
, approximately
20 km
above mouth, main channel, lateral channels and ponds,
USNM 280712
,
3
of 4,
76.8–81.7 mm
SL.
Diagnosis
.
Laemolyta proxima
differs from
L. garmani
and
L. taeniata
in having more longitudinal rows of scales from the lateral line to the dorsal-fin origin (6–8
vs.
4–5) and also from
L. garmani
in having more longitudinal rows of scales from the lateral line to the anal-fin origin (5–6
vs.
4).
Laemolyta proxima
differs from
L. orinocensis
in having fewer scales along the lateral line (43–47, usually 45
vs.
47–52).
Laemolyta proxima
has fewer perforated scales along the lateral line than does
L. fernandezi
(43–47
vs.
49–58).
Description
. Meristic and morphometric data presented in
Table 5
. Body moderately large (SL =
48.1–249.9 mm
SL). Dorsal profile of body straight from tip of snout to end of supraoccipital spine, slightly convex from that point to origin of dorsal fin, straight and posteroventrally-inclined along dorsal-fin base and straight and posteroventrally-inclined or slightly convex from posterior margin of dorsal-fin base to caudal peduncle. Ventral profile of body almost straight from tip of lower jaw to region near isthmus, slightly convex from that point to origin of anal fin, and slightly concave at insertion of pelvic fins.
Gill rakers on dorsal limb of first branchial arch 9–12 and 10–14 on lower limb.
Perforated scales on lateral line 43–47 (46*, usually 45,
Table 2
). Longitudinal scale rows from lateral line to dorsalfin origin 6–8 (6*, usually 6); scales rows from lateral line to anal fin origin 5–6 (5*, usually 5). Predorsal scales irregularly arranged. Scales rows around caudal peduncle 16 (16*).
Dorsal-fin rays ii–iii,10–12 (11*, usually 11); distal margin of fin convex. Anal fin short, slightly falcate, with i–ii,8 rays. Pectoral fin rays i,11–16 (13*, usually 13). Pelvic fin rays i,7– 9 (8*, usually 8); distal margin of fin truncate. Vertebrae 41–42 (42*, usually 42, N=5).
Color in alcohol
. Dorsal region of body of adult specimens (
Fig. 20
) generally dark, extending ventrally to within 1–1.5 longitudinal scale rows above lateral line. Sometimes inconspicuous dark midlateral longitudinal stripe, covering 1.5 to 2
40 Revision of the South American Anostomid genus
Laemolyta
longitudinal scale rows extending from tip of snout to rear of caudal peduncle. Stripe ends in form of triangular or ovalshaped dark spot. Ventral part of body lighter from lower limit of longitudinal dark stripe to midlateral line. Four vertical dark bars sometimes crossing body, first located between opercle and dorsal fin nearer to opercle, second under dorsal fin, third between pelvic and anal fins, and fourth anterior to vertical through base of adipose fin. Young specimens with highly variable number of narrow, transverse, dark bars (up to 26) extending from dorsal margin of body to near lateral line. Dorsal, pectoral, pelvic and caudal fins hyaline. Anal and adipose fins with scattered dark chromatophores.
Fig. 20.
Adult specimen of
Laemolyta proxima
, MZUSP
61642, 180.3 mm SL; Brazil, Roraima, rio Branco, Marará, Paraná-praia.
Several specimens from the rio Tapajós have the body coloration very light with the dorsum dark and the remaining parts of body almost entirely silvery.
Santos (1982)
examined young specimens (up to
70 mm
SL) bearing 12 to 16 dark, vertical bars on the dorsal part of the body. According to author, specimens longer than
70 mm
SL tend to loose most of these bars, with only those which form the four bars found in adult specimens retained. In the present study 14 to 26 dark, vertical bars were found in specimens smaller than
88 mm
SL, with most having 14 to 16 bars. Other specimens did not show any dark bars or spots on the body probably due to the method of preservation. In some other individuals, only the longitudinal stripe (
Fig. 21
) and the transverse, dark bars or oval-shaped spots over the inconspicuous longitudinal stripe (
Fig. 22
) were visible.
Distribution
. Amazon basin (
Peru
and
Brazil
) and
Essequibo
River in Guiana (
Fig. 13
).
Remarks
.
Laemolyta proxima
was described by
Garman (1890)
as
Anostomus
(
Schizodontopsis
)
proximus
together with
A.
(
Schizodontopsis
)
varius
and
A.
(
Schizodontopsis
)
nitens
.
These three species were recognized as distinct by
Borodin (1931)
who, nonetheless, considered the first
A. proximus
and
A. varius
to be very similar on the basis of their body shape and color pattern, and with
A. nitens
very similar to
A. varius
but having the body more elongate and with an overall lighter coloration.
Géry (1974)
considered these three species as part of a complex and divided that into two units: the
proxima-varia
group, which was characterized by the presence of a dark, midlateral longitudinal stripe and
nitens
, which had dark spots over an inconspicuous dark longitudinal stripe, a larger orbital diameter, and the body more elongate. In the same paper, Géry cast doubts on the recognition of two different species within the first group. The same author (1977) included
Laemolyta
as a subgenus of
Anostomus
,
considered
L. nitens
to be a valid species and provided an identification key which suggested that
Anostomus
(
Laemolyta
)
proximus
is a synonym of
Anostomus
(
Laemolyta
)
varius
.
According to
Garman (1890)
Laemolyta proxima
would be closely related to
L. taeniata
from which it could be distinguished in having smaller and consequently more numerous scales. Indeed some of the examined specimens of
L. proxima
species have a color pattern identical to that of
L. taeniata
, but the differences in scale counts make their identification possible.
Notwithstanding the differences in color pattern and number of scales between
Laemolyta varia
and
L. proxima
reported by
Garman (1890)
, an examination of the
syntypes
of
L. varia
indicated that these characters fall within the range of variation found in
L. proxima
.
The two species are, thus, considered synonymous, with
L. proxima
utilized because it appears first in Garman’s publication.
Fig. 22.
Young specimen of
Laemolyta proxima
, MZUSP
27382, 92 mm SL; Brazil, Amazonas, Costa do Japão, Ressaca do Japão, lower rio Japurá.
Fig. 21.
Adult specimen of
Laemolyta proxima
, MZUSP
64066, 132.1 mm SL; Brazil, Pará, rio Trombetas, Lago Jacaré.
Table 5.
Morphometrics of
Laemolyta proxima
.
Character |
Lectotype |
N |
Range |
Mean |
SD |
Standard length (mm) |
165.3 |
243 |
48.1-249.9 |
154.8 |
- |
Percents of standard length |
Preanal distance |
80.9 |
243 |
75.9 - 82.5 |
79.3 |
1.24 |
Preventral distance |
46.5 |
243 |
44.3 - 51.1 |
47.2 |
1.18 |
Prepectoral distance |
21.8 |
243 |
20.1 - 28.7 |
23.3 |
1.37 |
Predorsal distance |
45.3 |
243 |
41.3 - 47.6 |
44.4 |
1.09 |
Body depth |
25.7 |
243 |
20.9 - 29.8 |
25.5 |
1.70 |
Caudal-peduncle depth |
9.74 |
243 |
8.70 - 11.0 |
9.8 |
0.43 |
Caudal-peduncle length |
11.5 |
243 |
10.0 - 14.0 |
11.9 |
0.71 |
Dorsal-fin length |
24.4 |
243 |
20.4 - 31.4 |
25.3 |
1.59 |
Ventral-fin length |
16.6 |
243 |
14.7 - 21.9 |
17.1 |
1.12 |
Pectoral-fin length |
16.6 |
243 |
13.8 - 24.5 |
17.2 |
1.09 |
Anal-fin length |
11.7 |
243 |
9.50 - 15.0 |
12.2 |
0.92 |
Head length |
22.0 |
243 |
19.9 - 27.4 |
22.8 |
1.40 |
Dorsal-fin base length |
13.9 |
243 |
13.0 - 15.7 |
14.3 |
0.51 |
Anal-fin base length |
9.10 |
243 |
7.70 - 10.8 |
9.2 |
0.58 |
Percents of head length |
Eye diameter |
30.2 |
243 |
27.4 - 40.9 |
31.7 |
2.40 |
Antorbital length |
40.9 |
243 |
31.6 - 41.3 |
36.8 |
1.93 |
Interorbital distance |
43.7 |
243 |
36.5 - 49.9 |
43.3 |
3.22 |
Body width opercle |
53.3 |
243 |
39.8 - 67.8 |
56.6 |
4.21 |
The color pattern described by
Garman (1890)
to characterize
Laemolyta nitens
dark longitudinal stripe, dark spots along the lateral line, and the presence in some specimens of narrow, dark, vertical bars and faint dark spot on the caudal peduncle also occurs in some specimens of
L. proxima
(
Fig. 22
). This, however, falls within the color pattern variation in this species. The comparison of meristic and morphometric data between the two nominal species failed to reveal any significant difference, and
L. nitens
is, thus, placed as a junior synonym of
L. proxima
.
Lasso (1992)
reported
Laemolyta proxima
from the río Suapare (tributary of the río Orinoco,
Venezuela
). Two out of the
3 specimens
in the lot that served as the basis of that record (MHNLS 5512) were examined. One specimen proved to be
L. taeniata
and the other
L. orinocensis
. The third specimen, probably the one illustrated in the paper, also looks very much like
L. taeniata
,
because of the clearly visible dark longitudinal stripe, and the whitish areas on the scales above the lateral line that form forming light stripes and which are characteristic of this species.
Data from Santos & Jégu (1996) indicate that
Laemolyta proxima
is found in floodplain lakes in large shoals during certain parts of the year, sometimes occurring together with
L. garmani
. Those authors note that
L. proxima
is fished commercially. The species is omnivorous, but feeds mainly on insect larvae and vegetable material (
Santos, 1982
). It is widely distributed through the Amazon Basin including
Peru
.
In the original description several specimens were designated
syntypes
of
Anostomus
(
Schizodontopsis
)
proxima
. The specimen in
MCZ
19331 was examined and is herein designated as the
lectotype
.