Comprehensive Description
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англиски
)
добавил Smithsonian Contributions to Zoology
Creagrutus hildebrandi Schultz
Creagrutus hildebrandi Schultz, 1944b:330, figs. 47–49 [type locality: Venezuela: Lago Maracaibo basin, Río Catatumbo system, Río Táchira, 7 km N of San Antonio; also Río Motatán, Río Jimelles, Río Palmar, Río San Juan, Río San Pedro, Río Machango, Río Negro, Río Apon, Río Socuy].—Fernández-Yépez and Martin, 1953:228 [Lago Maracaibo basin, Río Negro, Tokio, 16 km W of Machiques].—Géry, 1977:407 [as a possible synonym of Creagrutus anary Fowler, 1913].—Mago-Leccia, 1970:23, 70 [Venezuela: Lago Maracaibo].—Vari and Howe, 1991:15 [location of type series].—[Not Cala, 1990:92].
DIAGNOSIS.—The combination of unmodified pores on the lateral-line scales, a completely pored laterosensory canal system on the body, a relatively broad third infraorbital, a straight to slightly convex predorsal profile, 10 to 12 anal-fin rays, and the distinct pattern of dark pigmentation on the middle rays of the caudal fin appearing as a basal caudal spot distinguishes Creagrutus hildebrandi from its trans-Andean congeners.
DESCRIPTION.—Body moderately elongate and somewhat to highly compressed in adults, typically less compressed in smaller individuals. Greatest body depth at dorsal-fin origin (Figure 12). Dorsal profile of head distinctly convex from margin of upper lip to vertical through posterior nares, nearly straight from that point to dorsal-fin origin, or with slight convexity between supraoccipital and dorsal-fin origin. Dorsal profile of body straight from dorsal-fin origin to adipose fin. Ventral profile of head with rounded obtuse angle midway between margin of upper lip and posterior of dentary, typically gently rounded from that point to pelvic-fin origin, slightly convex from that point posteriorly to caudal peduncle.
Upper jaw distinctly longer than and overhanging lower. Anterior portion of snout fleshy, with scattered minute papillae. Concentration of papillae on upper lip and margin of upper jaw continuing into mouth on fleshy flaps between premaxillary teeth. Lower jaw distinctly fleshy, with papillae concentrated on lip and scattered across lower jaw. Elements of infraorbital series well developed but with ventral margin of third infraorbital falling short of ventral limb of preopercle and posterior margin falling short of vertical limb of preopercle; posterior and ventral of margin of infraorbital series rounded, concentric relative to posteroventral margin of orbit.
Teeth arranged as in Creagrutus brevipinnis.
Dorsal fin with ii,8 rays. Dorsal-fin origin situated slightly anterior to vertical through pelvic-fin origin. Distal margin of dorsal fin concave with anterior rays elongate. Anal fin with ii,10–12 rays. Anal fin of males with hooks on posterior branches of first and sometimes second branched fin rays. Distal margin of anal fin concave with anterior rays somewhat elongate, forming distinct lobe in some individuals. Pectoral-fin length variable, ranging from approximately three-quarters distance to pelvic-fin origin to somewhat beyond that point. Pelvic fin with i,7 rays. Pelvic-fin length variable, reaching posteriorly to anal-fin origin in majority of specimens; males with hooks, when present, on all branched rays.
COLOR IN LIFE.—Schultz (1944b:333) commented that in life Creagrutus hildebrandi has the “dorsal fin pinkish, back yellowish; adipose fin orange-yellow; dorsal part of eye bright red; upper and lower lobes of caudal fin yellowish; anal fin pinkish anteriorly; pectorals pale orange-yellow; lateral band plumbeous, ending in a black spot at midbase of caudal fin; humeral bar black; sides silvery.”
A B
MORPHOMETRICS
Standard Length 50.3 32.5–63.3
1. Snout to anal-fin origin 62.6 61.4–67.3
2. Snout to pelvic-fin origin 44.7 44.3–52.1
3. Snout to pectoral-fin origin 24.9 44.3–52.1
4. Snout to dorsal-fin origin 45.3 45.2–49.4
5. Dorsal-fin origin to hypural joint 55.7 52.4–58.9
6. Dorsal-fin origin to anal-fin origin 32.4 30.4–35.4
7. Dorsal-fin origin to pelvic-fin origin 27.6 25.6–31.9
8. Dorsal-fin origin to pectoral-fin origin 31.0 30.5–35.3
9. Caudal peduncle depth 12.5 11.1–13.0
10. Pectoral-fin length 21.5 19.8–22.9
11. Pelvic-fin length 15.9 16.0–17.9
12. Dorsal-fin length 24.9 23.1–28.0
13. Anal-fin length 19.1 19.0–23.4
14. Head length 25.4 25.3–29.1
15. Postorbital head length 41.4 39.0–46.3
16. Snout length 29.0 24.6–29.5
17. Bony orbital diameter 33.6 29.7–35.3
18. Interorbital width 33.6 29.7–35.3
MERISTICS
Lateral-line scales 27 34–37
Scale rows between dorsal-fin origin and lateral line
4 4
Scale rows between anal-fin origin and lateral line
3 3
Predorsal median scales 10 9–11
Branched dorsal-fin rays 8 8
Branched anal-fin rays 12 10–12
Branched pelvic-fin rays 7 7
Pectoral-fin rays 13 12–14
Vertebrae 35 35–37
COLOR IN ACOHOL.—Head with pattern of diffuse dark chromatophores on dorsal surface, most concentrated over fontanel and on snout, with distinct small crescent of dark pigmentation immediately in front of anterior nares. Continuous band of dark chromatophores extending posteroventrally from just anterior of nares to anteroventral margin of orbit, continuing beneath orbit, narrowing, and progressively more diffuse around posterior margin of orbit. Dorsum of body with scattered small chromatophores more concentrated over centers of exposed portions of scales. Scales of dorsolateral and lateral surfaces of body with dark chromatophores concentrated along posterior margins. Series of small chromatophores delineating myosepta above anal fin. Region anterior of humeral mark largely unpigmented. Humeral mark margin anteriorly concave, chromatophores darker and most concentrated dorsal of lateral line. Midlateral stripe formed by deep-lying, dark chromatophores, more diffuse anterior to vertical through dorsal-fin origin.
Caudal fin with distinct basal caudal spot, and dark chromatophores overlying rays, particularly on ventral lobe. Unbranched and first branched rays of anal fin usually without associated dark pigmentation; dark pigmentation associated with anterior surfaces of proximal half of other branched rays. Dorsal fin with dark chromatophores associated with unbranched rays and basal portions of branched rays. Dorsal-fin membranes with dark chromatophores, gradually becoming diffuse posteriorly. Pectoral and pelvic fins hyaline.
Ecology.—Schultz (1944a:178) described the type-locality as “Width of river bed up to 200 feet, but only a small flow of water among rubble bottom; current rapid; depth in pool up to 2 feet.” Most of the localities cited for paratypes were similar habitats, although in a few cases the bottoms were cited as muddy.
DISTRIBUTION.—Rivers draining into Lago Maracaibo and independent rivers draining into southeastern portions of Golfo de Venezuela (Figure 13). Creagrutus hildebrandi is the only member of the genus known from those latter drainages. Within the tributaries to Lago Maracaibo, C. hildebrandi was captured at the same locality as C. maracaiboensis at the type locality of that species and with C. paralacus in the Río Motatán basin in the southeastern portions of the basin (compare Figures 7 and 13).
MATERIAL EXAMINED.—2014 specimens.
VENEZUELA. Tachira: Río Catatumbo basin, Río Táchira, 7 km N of San Antonio, USNM 121482, 1 (50.3, holotype of Creagrutus hildebrandi); USNM 121491, 9 (8, 47.5–63.3, paratypes of Creagrutus hildebrandi). Zulia: Caño in Río Zulia system, 12 km S of intersection of Highways 6 and 2, INHS 60271, 27 (5, 40.4–54.4). Río Cachiri, near Embalse de Cachiri, MBUCV V-18269. Río Orope, at bridge between La Fria and La Honda, UF 30751, 23 (5, 38.3–45.2). Río Apón, ∼35 km S of Rosario, USNM 121486, 314 (paratypes of Creagrutus hildebrandi). Río Palmar near Totuma, ∼100 km SW of Maracaibo, USNM 121487, 219 (paratypes of Creagrutus hildebrandi). Río Palmar, at bridge, 70 km NW of Maracaibo, USNM 121495, 16 (paratypes of Creagrutus hildebrandi). Río Palmar, Hacienda El Milagro, NW of Villa del Rosario, at base of Sierra de Perija, MBUCV V-18283, 40. Río Negro, below mouth of Río Yasa, USNM 121488, 159 (paratypes of Creagrutus hildebrandi). Río Negro, 12 km S of Marchiques on road to Tucuco, INHS 59940, 19 (9, 32.5–44.5). Río Socuy, 3 km above its mouth, USNM 121483, 154 (paratypes of Creagrutus hildebrandi). Río Machango at bridge S of Lagunillas, USNM 121492, 66 (paratypes of Creagrutus hildebrandi). Río Machango, 20 km above bridge, S of Lagunillas, USNM 121493, 11 (paratypes of Creagrutus hildebrandi). Municipio Ricuarte, Río Cachiri, MBUCV V-9224, 4. Trujillo: Río Motatán, 8 km below Motatán, USNM 121490, 148 (paratypes of Creagrutus hildebrandi). Río Motatán, at bridge, 22 km N of Motatán, USNM 121494, 261 (paratypes of Creagrutus hildebrandi). Río Motatán, 4 km above Motatán, USNM 121496, 403 (paratypes of Creagrutus hildebrandi). Río San Pedro, at bridge, Río Motatán system, USNM 121483, 1 (paratype of Creagrutus hildebrandi). Río San Juan near bridge, Río Motatán system, USNM 121484, 20 (paratypes of Creagrutus hildebrandi). Río Jimelles, 12 km E of Motatán, USNM 121485, 97 (10, 49.0–55.3, paratypes of Creagrutus hildebrandi). Falcon: Río Cocuiza, near Mene de Mauroa, at highway 3 bridge, INHS 59927, 5 (2, 33.3–35.6). Río Mojino, Río Maticora basin, near Las Palmas, INHS 60360, 9 (2, 39.8–46.2). Río Ricieto, Río Maticora basin, at town of Goajira, IHNS 60025, 7 (2, 36.3–43.5).
- библиографски навод
- Harold, Antony S. and Vari, Richard P. 1994. "Systematics of the trans-Andean species of Creagrutus (Ostariophysi:Characiformes:Characidae)." Smithsonian Contributions to Zoology. 1-31. https://doi.org/10.5479/si.00810282.551
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