Creagrutus brevipinnis Eigenmann 1913

Creagrutus brevipinnis Eigenmann

Creagrutus brevipinnis Eigenmann, 1913:10 [type-locality: Colombia: Piedra Moler; also specimens from Paila, Cartago]; 1920a:18 [Colombia: Río Magdalena basin]; 1920b:17 [Colombia: upper Río Cauca basin]; 1922:146 [Colombia: upper Río Cauca basin]; 1927:423, pi. 34: fig. 1 [Colombia: upper Río Cauca. Piedra Moler, Paila, Cartago].—Miles, 1943:55 [Colombia: Río Cauca; distinctiveness from Creagrutus caucanus questioned; differences between nominal species suggested to represent sexual dimorphism]; 1947:159 [as Miles, 1943].—Dahl, 1971:137, fig. [Colombia: upper Río Cauca; distinctiveness from Creagrutus caucanus discussed].—Miles, 1973:50 [as Miles, 1943].—Géry, 1977:410 [Colombia: upper Río Cauca].—Fowler, 1975:26 [literature compilation].—Ibarra and Stewart, 1987:28 [location of holotype and portion of paratypic series].—Román-Valencia, 1988:110 [Colombia: upper Río Cauca].—Vari and Howe, 1991:15 [location of portion of paratype series].

DIAGNOSIS.—The combination of unmodified lateral-line scales, a completely pored laterosensory canal system on the body, a broad third infraorbital, a convex asymmetrical predorsal profile, lack of a distinct pattern of dark pigmentation on the middle rays of the caudal fin, an apparently elongate caudal peduncle with a depth 9.6%–12.4% of SL, and 36 to 38 lateral-line scales distinguishes Creagrutus brevipinnis from its trans-Andean congeners.

DESCRIPTION.—Body moderately elongate and somewhat compressed in adults, less so in smaller individuals. Greatest body depth at, to somewhat anterior of, dorsal-fin origin. Dorsal profile of head distinctly convex from margin of upper lip to vertical through posterior nares, nearly straight from that point to supraoccipital. Dorsal profile of body with notable change in alignment relative to that of head, convex from anterior portion of supraoccipital to dorsal-fin origin; convexity asymmetrical, most pronounced in anterior one-third of predorsal profile. Dorsal profile slightly concave from dorsal-fin origin to adipose fin. Ventral profile of head with obtuse angle approximately midway between margin of upper lip and posterior of dentary, slightly convex from that point to anal-fin origin.

Head relatively depressed, particularly apparent in larger specimens. Upper jaw distinctly longer than and overhanging lower. Anterior portion of snout fleshy. Minute papillae widely distributed over anterior portion of snout, upper lip, and margin of upper jaw, continuing into mouth on fleshy flaps between premaxillary teeth. Lower jaw fleshy, with papillae most concentrated on lip and with progressively decreasing concentrations on jaw posteriorly as far as isthmus. Elements of infraorbital series well developed, with ventral margin of third infraorbital extending to ventral limb of preopercle and posterior margin closely approaching vertical limb of preopercle; posterior and ventral margins of third infraorbital approximately at perpendicular with posteroventral corner of bone broadly rounded.

Teeth arranged as described under “Dentition in Trans-Andean Creagrutus Species.”

Dorsal fin with ii,8 rays. Dorsal-fin origin at vertical through pelvic-fin origin. Distal margin of dorsal fin with anterior lobe formed by second unbranched and first two branched rays, overall border slightly concave. Anal fin ii or iii,8–10 rays; when three unbranched rays present first very small. Anal fin of males with series of hooks on first branched ray and sometimes one or two hooks on second branched ray. Most specimens with one hook per ray segment, but some individuals with two hooks on some segments, and one specimen with mostly two hooks per segment. Distal margin of anal fin slightly concave with distinct anterior lobe. Pectoral fin reaching posteriorly slightly over three-quarters distance to pelvic-fin origin. Pelvic fin with 1 unbranched ray followed by typically 7, sometimes 8, branched rays. Pelvic fin reaching posteriorly to slightly anterior of pelvic-fin origin; males with hooks on segmented and unsegmented portions of all branched rays.

Gill rakers 16–19 (based on 8 specimens).

COLOR IN LIFE.—Unknown.

COLOR IN ACOHOL.—Head with distinct pattern of diffuse dark chromatophores on dorsal surface and small crescent of dark pigmentation immediately anterior of nares. Band of scattered dark chromatophores extending from middle of snout posteriorly to anteroventral margin of orbit, narrowing and continuing around ventral and posterior margins of orbit to merge dorsally into diffuse pigmentation on lateral and dorsolateral surface of head. Dorsal portion of body with scattered small chromatophores more concentrated over centers of exposed portions of scales. Region anterior of humeral bar unpigmented. Humeral bar vertical, chromatophores most concentrated dorsal of lateral line. Midlateral stripe masked by guanine in available specimens, diffuse anteriorly.

Caudal fin with series of dark chromatophores along margins of four central rays, most concentrated basally and with appearance of diffuse spot. Dorsal and ventral procurrent rays with concentration of dark chromatophores. Distal pigmentation present on all of ventral caudal rays and those of dorsal lobe above approximately seventh ray. Anal fin with membrane between last unbranched and first branched rays hyaline; posteriorly, membranes with dark pigmentation most concentrated distally on middle rays, associated rays with scattered chromatophores. Narrow band of dark chromatophores across bases of branched anal-fin rays. Dorsal fin with last unbranched and anterior branched ray with dark chromatophores that continue posteriorly across distal portion of remaining branched rays, field of chromatophores becoming gradually narrower posteriorly. Dorsal-fin rays with dark chromatophores forming a basal band. Pectoral and pelvic fins hyaline.

DISTRIBUTION.—Known only from a limited region in the upper portion of the Río Cauca, northwestern Colombia (Figure 11); perhaps as a consequence of limited collecting in that region. Creagrutus brevipinnis is sympatric with C. caucanus at least at several localities in the basin.

MATERIAL EXAMINED.—82 specimens.

COLOMBIA. “Upper Río Cauca and tributaries,” USNM 120148, 3 (42.7–46.3); MCZ 35884, 3 (2, 47.8–48.1). Valle: Piedra Moler, FMNH 56095, 1 (49.4, holotype of Creagrutus brevipinnis; formerly CM 4887a); FMNH 56096, 10 (paratypes of Creagrutus brevipinnis; formerly CM 4887b–i); FMNH 75172, 34 (15, 34.3–47.4, paratypes of Creagrutus brevipinnis; formerly CM 4887b–i); CAS 41341, 11 (5, 35.5–43.0, paratypes of Creagrutus brevipinnis; formerly IU 12728, in part; 1 specimen of Creagrutus magdalenae in lot); USNM 79188, 4 (3, 33.5–43.0, paratypes of Creagrutus brevipinnis; formerly CM 4887b–i, in part). Paila, FMNH 56098, 10 (4, 36.7–45.2, paratypes of Creagrutus brevipinnis; formerly CM 4889a–h). Cartago, FMNH 56097, 5 (33.2–37.7, paratypes of Creagrutus brevipinnis; formerly CM 4888a–e).