The loricariid catfish genus Lasiancistrus (Siluriformes) with descriptions of two new species
Author
Armbruster, Jonathan W.
text
Neotropical Ichthyology
2005
2005-12-31
3
4
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http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1679-62252005000400013&lng=en&tlng=en
journal article
10.1590/S1679-62252005000400013
1982-0224
5417950
CC3E5EBD-AEB8-40A9-AE1D-4F1BF44D72BC
Lasiancistrus tentaculatus
,
new species
Fig. 9
Holotype
.
MCNG
19744, 147.6 mm
SL, río
Las Marias
, near
El Portrero
, below the metal bridge,
09°05’N
,
69°39’W
,
D. C. Taphorn
,
A. Flecker
,
B. Feifarek
,
L. Van Balen
,
12 Nov 1986
.
Paratypes
.
All collections
Venezuela
.
Apure
:
INHS
28283, 44 (5 measured), 2 c&s,
52.9-76.8 mm
SL, tributary to río Suripa,
36 km
NE La Pedrera on highway 5, L. M. Page, B. M. Burr, P. A. Ceas, C. A. Taylor & S.
R
. Walsh,
6 Jan 1992
.
Carabobo
, río Orinoco drainage:
MCNG
15345, 1,
89.5 mm
SL, caño Guamita, highway to los Naranjos, approximately
15 km
from the crossroads,
10°02’50"N
,
067°54’30"W
, D. Taphorn, S. Reid, & C. Olds,
19 Oct 1986
.
Barinas
, río Orinoco drainage:
INHS
29866, 48 (1 measured), 6 c&s, 77.0 mm SL, caño Yaure, Yaure on highway 5, 36 km NE La Pedrera,
7°42’05"N
, 71°17’77"W, L. M. Page, S. Huhndorf, & J. L. Crane,
26 Jan 1993
.
Cojedes
, río Orinoco drainage:
INHS
28988, 2, 49.0-
69.8 mm
SL, río San Carlos WNW Las Vegas,
9°33’40"N
, 68°38’89"W, J. W. Armbruster, D. C. Taphorn, L. M. Page, K. S. Cummings, C. A. Mayer, P.A. Ceas, C. A. Laird & M.H. Sabaj,
9 Jan 1993
.
INHS
29062, 6 (2 measured),
58.3-79.3 mm
SL, río Camoruco, about
10 km
NW Libertad, D. C.Taphorn, L. M. Page, K. S. Cummings, C. A. Mayer, P.A. Ceas, J. W.Armbruster, C. A. Laird & M. H. Sabaj,
9 Jan 1993
.
INHS
32030, 3 (1 measured),
67.3 mm
SL, río San Carlos,
2 km
W Las Vegas at caño Hondo, on rd. from Las Vegas to Libertad,
9°31’51"N
,
68°39’39"W
, J. W. Armbruster, M. H. Sabaj, K. S. Cummings & C.A. Mayer,
14 Jan 1994
. J. W. Armbruster, P.A. Ceas, M. Campos,
R
. Suarez & J. A. Llerandi,
16 Jan 1995
.
Guarico
, río Orinoco drainage:
ANSP
163455, 1, 38.0 mm SL, Tributary of río Paya (tributary of río
Guarico
),
23 km
S of San Juan de los Morros on Federal Highway 2, N.
R
. Foster,
29 Nov 1966
.
INHS
34617, 2,
59.6-68.9 mm
SL, río San Jose, Parque Nacional Aguaro-Guariquito,
9°28’55"N
,
66°53’19"W
, J. W. Armbruster, P. A. Ceas, M. Campos,
R
. Suarez & J. A. Llerandi,
16 Jan 1995
.
Portuguesa
, río Orinoco Drainage:
AUM
17181, 2, 59.3-60.0 mm SL, caño Maraca, tributary of the caño Igues, Guanare-Guanarito road at road km 60,
8.8275°N
,
069.345W
, J. W. Armbruster, M. Hardman, J. D. Evans, & J.A. Thomas,
17 Dec 1999
.
AUM
27728, 3, 67.0-
71.7 mm
SL, caño Las Marias, tributary of the río
Portuguesa
, at town of Quebrada Seca, approximately 45 min. upstream by car from Hwy. 5, 22 km NNW Guanare, J. W.Armbruster & O. León,
28 Feb 1998
.
AUM
22663, 8 (4 measured),
52.1-94.4 mm
SL, caño Mamón, tributary of río
Portuguesa
, in El Mamón,
24 km
E Guanare,
9.07167°N
,
069.515°W
, J. W.Armbruster, M. Hardman, J. D. Evans, & J. A. Thomas,
2 Jan 2000
.
AUM
22792, 3 (1 measured),
76.6 mm
SL, río
Portuguesa
, at Hwy 5 bridge,
9.0818°S
,
069.68159°W
, J. W.Armbruster, M. Hardman, J. D. Evans, & J. A. Thomas,
31 Dec 1999
-
1 Jan 2000
.
AUM
22833 4 (2 measured),
66.7-80.8 mm
SL, same locality and collectors as
AUM
17181,
1 Jan 2000
.
AUM
41708, 4 (0 measured), same locality as
AUM
22792, M. H. Sabaj, D. C. Werneke, N. K. Lujan, L. S. de Souza, & O. Leon,
29 Mar 2004
. CU 82650, 1,
84.3 mm
SL, río Las Marias, río
Portuguesa
drainage,
9.2000°N
,
69.7000°W
, P. B. McIntyre
et al
.,
31 Jan 2001
.
INHS
28650,
1, 105.5 mm
SL, río
Portuguesa
at Mata Larga, D. C. Taphorn, L. M. Page, K. S. Cummings, C. A. Mayer, P. A. Ceas, J. W.Armbruster, C. A. Laird & M. H. Sabaj,
1 Jan 1993
.
MCZ
59382, 4 (2 measured), 57.4-67.0 mm SL, same locality as
AUM
17181, D. C. Taphorn
et al
.,
19 Mar 1983
.
UF
32331, 1,
76.5 mm
SL, río Tucupido just behind the Santuarío de la Coromoto, ca
1.7 km
SW of Guanare, just above junction with río Guanare, D. C. Taphorn
et al
.,
26 Mar 1981
.
UF
80706, 4,
41.1-63.7 mm
SL, río Bocono in Puerto Paez, Portuguesa-
Barinas
border, D. C. Taphorn, C.
R
. Gilbert, & L. Nico,
10 Apr 1984
.
Trujillo
, río Orinoco drainage:
MCNG
27307, 4,
62.6-84.6 mm
SL, río Carache,
27 Aug 1990
.
Nontypes.
Colombia
.
Meta
,
río Orinoco
drainage:
ANSP 128692
,
5
, 41.0-
58.3 mm
SL,
río Negro
, downstream from main Villavicencio-
Puerto Lopez
highway at
La Balsa, W
side of river,
29 Feb 1972
.
ANSP 131661
, 0,
río Negrito
, downstream from bridge at
La Balsa
, río
Meta
drainage,
22 Mar 1975
.
UF 33421
,
1
, 51.0 mm SL,
Guacavia River
ENE of Villavicencio
,
3 Jan 1973
.
Venezuela
.
Amazonas
:
AUM
39278, 0,
río Parucito
,
río Ventuari Drainage
, at raudales
Salomon
,
2.7 km
NE of San Juan de Manapiare
,
05.34637°N
,
066.03347°W
,
16 Apr 2004
.
AUM
39849, 0,
río Ventuari
, beach below
Raudales Tencua
,
56 km
ESE of San Juan de Manapiare
,
05.04968°N
,
065.62722°W
,
19-20 Apr 2004
.
MCNG 23846
,
3
,
38.5-43.7 mm
SL, island in
río Ocamo
below
Arata
rapids,
03°05’S
,
64°37’W
,
24 Jan 1990
.
MCNG 24246
,
5
,
28.7-55.8 mm
SL,
río Putaco
near the confluence of the
río Ocamo
(river above Chicrita-
Pora Rapids
),
3 Feb 1990
.
MCNG 25802
,
1
,
33.5 mm
SL,
río Ocamo
at
Arata Rapids
,
03°08’N
,
64°34’W
,
24 Jan 1990
.
UF 77844
,
2
,
49.1-50.5 mm
SL,
río Ventuari
at
Tencua
just below
Tencua Falls
,
20 Mar 1981
.
Apure
,
río Orinoco
drainage:
MCNG 21802
,
1
,
41.8 mm
SL,
río Cinaruco
CORPOVEN camp,
06°31’50"N
,
067°26’14"W
,
20 Apr 1989
.
Bolivar
,
río Caura
drainage:
MCNG 21596
,
2
,
43.4-64.4 mm
SL, caño
Icutú
, two turns of the river below
Icutú Falls
,
05°N
,
064°W
,
13 Mar 1989
.
Diagnosis.
Lasiancistrus tentaculatus
is diagnosed by one unique autapomorphy, the presence of small tentacles (tentacules
sensu
Sabaj
et al
., 1999
) on the snout of nuptial males that are larger than the supporting odontodes. All other
Lasiancistrus
whose nuptial males have been observed have whiskerlike odontodes at the anterolateral corners of the snout. In addition,
L. tentaculatus
can be separated from
L heteracanthus
,
L. guacharote
, and some
L. schomburgkii
by having no plates on the abdomen, from
L. schomburgkii
and
L. saetiger
by having black spots in the dorsal, caudal, and paired fins fin (
vs.
no or white spots or entirely gray, respectively), and from
L. caucanus
by having a forked caudal fin (
vs.
emarginate).
Description.
Morphometrics in
Table 3
. Largest specimen
147.6 mm
SL. Morphometrics in
Table 2
. Largest specimen
100.1 mm
SL. Body strongly dorsoventrally compressed and moderately wide. Head and nape gently sloped to insertion of dorsal fin. Dorsal profile very slightly sloped ventrally to dorsal procurrent caudal-fin spines, then rising slightly to caudal fin. Ventral profile flat to caudal fin. Supraorbital ridge almost absent with interorbital space slightly concave, almost flat. Supraorbital ridge continues as slightly higher, rounded ridge from anterior of orbit to slightly anteroventral of anterior nare. Mesethmoid raised slightly above lateral surface of snout to form slight ridge. Head contours smooth. Eyes small to medium.
Fig. 9.
Dorsal, lateral, and ventral views of holotype of
Lasiancistrus tentaculatus
, MCNG
19744, 147.6 mm SL.
Keels absent. All plates slightly convex medially to produce cylindrical body. Mid-dorsal and mid-ventral plate rows incomplete, generally ending below adipose fin; three rows of plates on caudal peduncle. Abdomen naked. First anal-fin pterygiophore not exposed to form platelike structure. 23-25 (mode = 24) plates in median series.
Frontals, infraorbitals, nasals, opercles, pterotics, sphenotics, and supraoccipital supporting odontodes. Opercular odontodes occasionally moderately hypertrophied, thick, and sharp; whiskerlike odontodes rarely present on opercle. Whiskerlike odontodes present in evertible cheek mass and occasionally at anterolateral corner of snout; 1-26 whiskerlike odontodes in evertible cheek mass (mode = 5, N = 29); 12-60 (mode = 36, N = 31) total hypertrophied odontodes in cheek mass. Cheek plates evertible to approximately 90° from head, hypertrophied cheek odontodes folded under opercle when relaxed. Odontodes on tip of pectoral-fin spine slightly hypertrophied. Odontodes on lateral plates not enlarged to form keels.
Dorsal fin not reaching preadipose plate when adpressed; dorsal-fin spine not elongate, edge of dorsal fin straight. Dorsal-fin spinelet V-shaped, dorsal-fin spine lock functional. Dorsal fin II,7 (one of 76 I,6). Adipose fin with one preadipose plate and moderately long spine. Caudal fin slightly emarginate to forked, lower lobe longer than upper, i,14,i (two of 60 i,12,i), with four to five (mode = five, N = 26) dorsal procurrent caudalfin rays and four to five (mode = four, N = 25) ventral procurrent caudal-fin rays. Anal fin short with unbranched ray weak and usually about three quarters length of first branched ray. Anal fin i,5 (one of 76 i,4), Pectoral-fin spine reaching slightly posterior to insertion of pelvic fin when adpressed ventral to pelvic fin. Pectoral fin I,6 (one of 76 I,5). Pelvic fin reaching to posterior of anal-fin when adpressed. Pelvic fin i,5 (N = 78).
Dorsal flap of iris present. Flap between anterior and posterior nares short. Lips wide, fairly thin. Upper lip with small, round papillae. Lower lip with medium-sized papillae anteriorly and smaller ones posteriorly. Maxillary barbels very short, not reaching behind lower lip, occasionally completely adnate. Buccal papilla small. Jaws moderately wide, dentaries forming very oblique angle; premaxillaries forming very shallow arc with an overall angle just slightly less than 180°. Teeth with fairly long, narrow cusps; lateral cusp approximately half-length of medial cusp, stalks of teeth long; 39-88 dentary teeth (mode = 74, N = 23) and 29-89 premaxillary teeth (mode = 67, N = 27).
Color.
Body and head almost uniformly brown with slight mottling. Abdomen light tan, ventral surface of caudal peduncle slightly darker. Dorsal, caudal, and paired fins with dark spots centered on fin rays and that may form incomplete or wavy bands. Adipose and anal fins uniformly dark. Lower half of caudal fin generally darker than upper half.