Lasiancistrus caucanus Eigenmann, 1912

Armbruster, Jonathan W., 2005, The loricariid catfish genus Lasiancistrus (Siluriformes) with descriptions of two new species, Neotropical Ichthyology 3 (4), pp. 549-569 : 553-555

Lasiancistrus caucanus Eigenmann, 1912 Fig. 4

Lasiancistrus caucanus Eigenmann, 1912:11 .Cartago, Colombia, C. H. Eigenmann, Jan-Mar 1912.

Hemiancistrus mayoloi Eigenmann, 1912:10 . Río San Juan , Ismina, Colombia, 5°11’N, 76°39’W.

Ancistrus planiceps Meek & Hildebrand, 1913:79 . Río Tuyra, Boca de Cupe, Panama.

Lasiancistrus volcanensis Dahl, 1942: 83 . Río Volcán near its junction to río San Bartolomé, tributary of río Magdalena, Antioquia Dep., Colombia.

Material Examined. Colombia. State not given : FMNH 56034 , 1, 133.7 mm SL, holotype of L. caucanus , and FMNH 56035 , 4 , 77.9- 132.9 mm SL, paratypes of L. caucanus, Cartago, Jan-Mar 1912 . FMNH 56037 , 2 , 62.5-85.7 mm SL, paratypes of L. mayoloi, Istmina , 18 Mar 1912 . FMNH 58519 , 1, 105.4 mm SL, Piedra Moler , 21 Feb 1912 . FMNH 58560 , 1 , 54.3 mm SL, Paila , 1913 . FMNH 58561 , 0, Bernal Creek near Honda, 1913 . FMNH 76219 , 1 , 79.7 mm SL, no locality. USNM 120723 , 1 , 57.6 m SL, río Ariguanicito tributary of río Cesar, 24 Mar 1942 . USNM 308485 , 1 , 52.4 mm SL, río Salado, 4 miles above confluence with río Truando , 15 Mar 1967 . USNM 175318 , 2 , 75.7-91.9 mm SL, Batatal, río Ure , San Jorge, 23 Dec 1950 . Valle del Cauca, río Cauca - río Magdalena drainage: MCZ 35812, 1 , 80.4 mm SL, upper río Cauca and tributaries, Oct 1942 . MCZ 35871, 1 , 44.5 mm SL, upper Cauca, río Frío , 18 Oct 1942 . USNM 120155 , 1 , 73.5 mm SL, upper Cauca, río Frío , 18 Oct 1942 . Caldas, río Cauca drainage: ANSP 134248 , 7 , 88.1-139.4 mm SL, río Mercedes , 1.5 hr drive from Hacienda Sonadora, 23 Mar 1973 . Choco : ANSP 88385 , 4 , 171.1 - 187.8 mm SL, upper río Jaredo, Pacific Slope , elevation 600 ft., Oct 1940 . FMNH 56036 , 1 , 92.7 mm SL, holotype of L. mayoloi , upper río Jaredo , Pacific Slope, 18-20 Mar 1912 . USNM 308484 , 2 , 35.4 - 41.0 mm SL, río Atrato drainage, small river (río Cuti?) near Santa Maria La Nueva , lower Atrato , 29 Aug 1967 . USNM 308486 . 2, 57.8- 71.8 mm SL, creek of upper río Nercua, large tributary of río Truando , 28 Aug 1967 . USNM 308487 , 1 , 1 c&s, 99.0 mm SL, río Salado near Teresita , 8 Feb 1968 . Santander, río Magdalena drainage: SIUC 34914 , 92.3 mm SL, no precise locality given, Nov 1998 . Panama. State not given : USNM 280395 , 2 , 96.2-119.9 mm SL, Atlantic Ocean drainage, Comarca KunaYala, río Cangandio Mandinga confluence area, 09°26’N, 79°05’W, 6-10 Feb 1986 . USNM 308482 , 1, 117.1 mm SL, río Chucanaque, Pacific Ocean drainage, 09°02’N, 78°02’W, 1 Mar 1967 . USNM 308492 , 4 , 137.1 - 187.9 mm SL, río Pirre, Pacific Ocean drainage, 3-5 miles above El Real, purchased (caught on line), 23-27 Feb 1967 . Darien, Pacific Ocean drainage : FMNH 26290 , 1, 190.4 mm SL, paratype of L. planiceps , río Tuyra, at mouth of río Yape , 6 Mar 1912 . FMNH 26291 , 1, 127.3 mm SL, paratype of L. planiceps , río Tuyra, Boca de Cupe , 26 Feb 1912 . FMNH 26292 , 1 , 77.9 mm SL, paratype of L. planiceps , río Grande , Cana, 3 Mar 1912 . FMNH 26293 , 1 , 82.5 mm SL, paratype of L. planiceps , río Cana , Cana, 1 Mar 1912 . FMNH 29291 , 1, 137.4 mm SL, paratype of L. planiceps , río Tuyra, Boca de Cupe , 28 Feb 1912 . FMNH 29292 , 1, 130.8 mm SL, paratype of L. planiceps , río Tuyra, Boca de Cupe , 28 Feb 1912 . FMNH 29293 , 1, 178.1 mm SL, paratype of L. planiceps , río Tuyra, Boca de Cupe , 28 Feb 1912 . FMNH 7580 , 1, 147.6 mm SL, holotype of L. planiceps , río Tuyra, Boca de Cupe , 26 Feb 1912 . MCZ 88614, 2 , 62.2-86.8 mm SL, río Pucuro, 3-4 km above confluence with río Tuira , 8°0’N, 77°31’W, 17 Feb 1985 . USNM 078309 , 1 , 43.9 - 101.7 , río Grande , Cana, 3 Mar 1912 . USNM 078311 , 2 , 121.2 - 177.1 mm SL, río Tuyra, mouth of río Yape , 6 Mar 1912 . USNM 280394 , 1, 125.3 mm SL, río Tuira, between Calle Larga and Pinogana above El Real , 08°07’N, 077°42’W, 18 Feb 1985 . USNM 293415 , 4 , 1 c&s, 47.6-123.4 mm SL, río Pucuro just above confluence with río Tuira , 08°00’N, 077°32’W, 16-18 Feb 1985 . USNM 293418 , 1 , 138.0 mm SL, río Tuira , 0.5 km above Boca de Cupe, 08°03’N, 077°06’W, 18 Feb 1985 . Panama, río Bayano - Pacific Ocean drainage : ANSP 151026 , 9 , 62.7-85.3 mm SL, río Canitas at IAH about 10.4 km W of Bayano bridge, 31 Jan 1983 . MCZ 57075, 1 , 84.6 mm SL, probably río Canita , on large rock ledge 0.5 km upriver of construction camp and headquarters, 1 Apr 1978 . USNM 308490 , 3 , 122.8 - 175.7 mm SL, río Membrillo , 22 Mar 1967 .

Diagnosis. Lasiancistrus caucanus is distinguished from all other species of Lasiancistrus except L. saetiger , L. tentaculatus , and some L. schomburgkii by the absence of plates ventrally in front of the anus and from all Lasiancistrus except some L. guacharote by having the caudal fin slightly emarginate (vs. forked; Fig. 4 ). Additionally, L. caucanus can be separated from L. schomburgkii and L. saetiger by having dark spots in the dorsal fin (vs. dorsal fin all gray or with white spots); from L. tentaculatus by having tentacules along the snout that are shorter than their associated odontodes in nuptial males (vs. longer in nuptial males), and by having whiskerlike odontodes at the anterior corner of the snout in nuptial males (vs. whiskerlike odontodes absent, Fig. 2a ).

Description. See genus description for more information. Morphometrics in Table 1. Largest specimen 190.4 mm SL. Abdomen naked. 21-25 (mode = 24) plates in median series. 4- 35 whiskerlike odontodes in evertible cheek mass (mode = 11, N = 49); 21-76 (mode = 39, N = 57) total hypertrophied odontodes in cheek mass.

Color. Color variable. Body typically light brown with dark, wavy stripes that may break up into dashes or spots posteriorly. Light areas occasionally exist as spots rather than background color. Head mottled or with light spots. Body and head sometimes uniformly dark.Abdomen uniformly light tan, lower surface of caudal peduncle darker than abdomen. Dorsal fin with large, rectangular spots centered and darkest on fin rays, almost combing to form bands. Paired, caudal, and anal fins with narrow bands. Lower half of caudal fin slightly darker than upper. Adipose fin uniformly dark. Color darkens with size.

Sexual dimorphism. Nuptial males with whiskerlike odontodes at the anterolateral corner of the snout, else as in genus description.

Range. Lasiancistrus caucanus has a trans-Andean distribution in the ríos Magdalena, Atrato, San Juan, Tuyra, and Bayano drainages of Colombia and Panamá ( Fig. 3 ).

Comments: Lasiancistrus caucanus and L. mayoloi were both described by Eigenmann (1912); however, L. mayoloi was described in Hemiancistrus . Because L. caucanus was described in the correct genus and L. mayoloi was not, L. caucanus was chosen as the valid name for the species. The type of Lasiancistrus volcanensis was not examined; however, no significant differences could be found in any of specimens examined from west of Lago Maracaibo. The figures in Dahl (1942) appear identical to all other specimens collected in the region, so L. volcanensis is listed as a synonym of L. caucanus .

Most specimens available have the colors faded, but those that do have color left show little variation across the trans- Andean region they occupy and no other characteristics could be found to support any of the species listed above as synonyms. The only difference in color pattern is from specimens collected from the río Bayano, the furthest west river in the range of L. caucanus in Panamá. These specimens have the light areas of the body as spots instead of forming a light background; however, the other elements of the color pattern are as in the rest of the species. Few specimens are available from the Bayano to make comparisons, so it is unknown if this population would require separate species status.

Figures

Fig. 4. Dorsal, lateral, and ventral views and inset of extended caudal fin of Lasiancistrus caucanus, SIUC 34914, 92.3 mm SL.

Fig. 2. Heads, dorsal view showing whiskerlike odontodes on cheek (a and b), whiskerlike odontodes on snout (a) and tentacules on snout (b) a. Lasiancistrus guacharote, ANSP 128695, 123.4 mm SL, b. Lasiancistrus tentaculatus, INHS 28650,105.5mmSL.

Fig. 3. Range of species of Lasiancistrus. Open symbols are type localities except for in L. heteracanthus where the type locality is not specific. Triangles = L. schomburgkii, squares = L. caucanus, upside down triangles = L. guacharote, diamonds = L. heteracanthus, cross = L. saetiger, and circles = L. tentaculatus. The following are type localities for species in synonymy that have good locality information: 1. L. castelnaui (locality approximate), 2. L. guapore, 3. L. maracaiboensis, 4. L. mayoloi, 5. L. planiceps, 6. L. scolymus, 7. L. volcanensis.