Creagrutus andaki, Albornoz-Garzón & Acosta-Santos & Bogotá-Gregory & Agudelo-Córdoba, 2020

Albornoz-Garzón, Juan G., Acosta-Santos, Astrid, Bogotá-Gregory, Juan D. & Agudelo-Córdoba, Edwin, 2020, A new species of Creagrutus Günther (Characidae: Stevardiinae) from the Amazonian Piedmont of Colombia, Zootaxa 4755 (2), pp. 365-374 : 366-370

Creagrutus andaki , new species

( Figs.1–3 ; Table 1)

urn:lsid:zoobank.org:act:46CD684B-3465-4D53-900B-9618B4940066

Holotype. CIACOL 3462, 56.8 mm SL, Colombia, Caquetá, Florencia, Río Caquetá basin, Río Hacha drainage, Río Sucre, km 61, bridge at old road to Neiva , 01º47’43.2”N, 75º38’48.9”W, 1015 masl; J. D. Bogotá-Gregory & I. González-Gómez, 10 August 2018.

Paratypes. All from the same locality of the holotype: CIACOL 3463 (4, 38.7–58 mm SL), same data as holotype; CIACOL 2130 (7, 1 C & S, 35.8–64.6 mm SL); CZUT-IC 19973 (2, 35.9–57 mm SL); IAvH-P 20565 (2, 1 C & S, 50.6–54.7 mm SL), E. Agudelo-Córdoba, J D. Bogotá-Gregory, A. Acosta-Santos & I. González-Gómez, 12 August 2016; CIACOL 2910 (1, 58.7 mm SL); E. Agudelo-Córdoba, J D. Bogotá-Gregory, A. Acosta-Santos, 12 August 2017 .

Diagnosis. Creagrutus andaki differs from all its congeners, except for C. cacique , C. gyrospilus , C. melasma , C. nigrotaeniatus , C. ouranonastes , C. planquettei , C. tuyuka , C. varii and C. yanatili by having a dark, relatively broad midlateral stripe starting at anteriormost scale of lateral line (vs. midlateral stripe absent or starting posterior to humeral blotch). The new species is differentiated from C. gyrospilus , C. planquettei , and C. yanatili by having humeral blotch vertically elongated (vs. humeral blotch absent or oval shaped). Creagrutus andaki differs from C. cacique , C. melasma and C. tuyuka by lacking a dark blotch on dorsal fin (vs. dorsal fin with a dark blotch). Creagrutus andaki can be distinguished from C. ouranonastes and C. varii by the absence of a dark blotch on base of middle rays of caudal fin (vs. presence of a dark blotch on base of middle rays of caudal fin). Creagrutus andaki is differentiated from C. nigrotaeniatus by having a larger number of predorsal scales (11–12 vs. 8–9), by the morphology of the dentigerous surface in ventral view (triangular vs. longitudinally elongate), and by the number of dentary teeth (5–6 vs. 8–10).

Description. Morphometric data are given in Table 1. Body moderately elongate. Greatest body depth between half distance between pectoral- and pelvic-fin origins. Head slightly pointed, its dorsal profile convex from the margin of the upper lip to vertical through posterior margin of posterior nostrils, then straight to slightly convex from latter point to end of supraoccipital spine; interorbital region transversely convex. Dorsal profile slightly convex from tip of supraoccipital spine to dorsal-fin origin; nearly straight and posteroventrally slanted from latter point to adipose fin, and concave from later point to anteriormost procurrent caudal-fin rays. Ventral profile of head slightly convex to antero-ventral corner of dentary, then straight to isthmus. Ventral profile of body slightly convex from isthmus to anal-fin origin; anal-fin base straight; straight to slightly concave from the base of last anal-fin ray to procurrent caudal-fin rays. Some specimens with tubercles with keratinized caps distributed on dorsal region of head. Infraorbital series moderately developed. Central portion of ventral margin of third infraorbital horizontally straight, in contact with horizontal limb of preopercle. Posterior margins of third through fifth infraorbitals distinctly separated from vertical limb of preopercle.

Mouth subterminal, upper jaw conspicuously protruding beyond lower jaw; outer row of premaxillary teeth slightly exposed in ventral view. Corner of mouth located at horizontal line that crosses below ventral margin of eye. Premaxilla with three series of tricuspid teeth: first row irregular, with 5(1) or 6(1) teeth of equal size forming arc without distinct gap between first and second teeth, 5 from 17 examined specimens presenting gap ( Fig. 3 ). Second row in cluster of 3(2) teeth, larger than teeth from first row, third row with 1(1) or 2(1) teeth, slightly thinner than remaining teeth, located next to third and fourth teeth from first row. Maxilla with 2(1) or 3(1) tricuspid teeth, of equal size. Dentary with 5(1) or 6(1) tricuspid teeth, anteriormost three teeth larger than remaining teeth. First branchial arch with 1(1) or 2(1) gill rakers on hypobranchial, 7(1) or 8(1) gill rakers on ceratobranchial, and 6(1) or 7(1) gill rakers on epibranchial. Branchiostegal rays 4(2).

Scales cycloid, circuli restricted to anterior part of scales, with 10–16 wavy radii, that extend parallel from scale center to its posterior margin. Lateral line slightly curved ventrally, with 40*(9) or 41(6) pored scales. Four(2) or 5*(12) scales between dorsal-fin origin and lateral line; 3*(15) scales between lateral line and pelvic-fin insertion. Predorsal scales 11*(14) or 12(1). Postanal scales 2*(7), 3(7) or 4(1). Caudal fin with scales on first or second third of each lobe, similar in size to scales of body.

Dorsal-fin rays ii,8*(15), dorsal-fin origin anterior to pelvic-fin insertion, distal dorsal-fin margin slightly concave, with third and last two rays longer than remaining rays, fleshy interradial folds present. Anteriormost dorsal-fin pterygiophore inserted posterior to neural spine of 10th(2) vertebra. Anal-fin rays iii(2), 9(3) or 10*(12), distal profile concave, last unbranched and first two branched rays slightly longer. Fleshy interradial folds present. Anteriormost anal-fin pterygiophore inserted posterior to neural spine of 19th (2) vertebra. Pectoral-fin rays i,9(3) or 10*(12), its posterior tip not reaching vertical through pelvic-fin insertion. Fleshy interradial folds present. Pelvic-fin rays i,7*(15), distal tip not reaching anal-fin origin. Fleshy interradial folds present. Adipose-fin origin at vertical posterior through last anal-fin ray insertion. Caudal fin forked, lobes approximately similar in size. Principal caudal-fin rays i,10+9,i(2). Dorsal caudal fin procurrent rays 13(1) or 14(1), ventral caudal-fin procurrent rays 12(2). One pair of uroneurals. Supraneurals 5(2). Ribs 12(1) or 13(1). Vertebrae 38(2).

Color in alcohol. Overall ground coloration beige. Dorsal region of body dark. Humeral blotch dark, vertically elongated, in some specimens anteriorly concave, encompassing longitudinally from second to fourth scale of lateral line and five scales vertically. Dark, relatively broad midlateral stripe starting at anteriormost scale of lateral line, extending to base of caudal peduncle. Dark chromatophores aligned with margins of myomeres, starting slightly posterior to anal-fin origin. Dorsal region of the head, upper lip, and anterior third of maxilla lightly dark; ventral and dorsal margins of orbit dark; preopercle and opercle silvery. Dorsal fin with melanophores concentrated on interradial membranes; pectoral fins with some melanophores along border of rays; pelvic, anal and caudal fins with scattered melanophores. Melanophores on caudal fin somewhat concentrated in the basal portion of the lobes. Dorsal and ventral procurrent rays dusky. Adipose fin dusky ( Fig. 1 ).

Sexual dimorphism. No secondary sexually dimorphic characters were observed. However, it should be noted that all specimens were collected during the same month (August).

Distribution. Creagrutus andaki is known only from its type locality in the Río Sucre, Río Hacha drainage, Río Caquetá basin, Caquetá, Colombia ( Fig. 4 ).

Etymology. The specific epithet “andaki” honor the native indigenous people Andakí or Andaquí, who occupied several sites of the Upper Río Caquetá basin and fought bravely during the Spanish conquest. A noun in apposition.

Habitat and ecological notes. The Río Sucre is a piedmont stream with transparent waters, with many rapids alternated with relatively few pools, substrate composed mainly by boulders, with some areas with cobbles, and margins with a well-developed riparian vegetation ( Fig. 5 ). Some physical and chemical parameters of the Río Sucre are: temperature 18.4–20.2°C, dissolved oxygen 7.6–8.3 mg O/l, pH 5.5–8, conductivity 19–23 µS/cm, average flow 0.370 m /s, total width 7.50 m, and discharge 2 m 3 /s and 1997 L/s. Creagrutus andaki is found syntopically with Othonocheirodus sp., Characidium boehlkei Géry and Astroblepus caquetae Fowler. Stomach contents of two cleared and stained specimens (CIACOL 2130 and IAvH-P 20565) included insects, fragments of seeds and unidentified organic material.

Figures

FIGURE 1. Creagrutus andaki, holotype, CIACOL 3462, 56.8 mm SL, Colombia, Caquetá, Florencia, Río Caquetá basin, Río Hacha drainage, Río Sucre.

FIGURE 2. Creagrutus andaki, paratypes: (A) CIACOL 2910, 58.7 mm LS. (B) CZUT-IC 19973, 57.4 mm LS. (C) CIACOL 3463, 38.6 mm LS. All from Colombia, Caquetá, Florencia, Río Caquetá basin, Río Hacha drainage, Río Sucre.

FIGURE 3. Creagrutus andaki, IAvH-P 20565, paratype, 50.6 mm SL, premaxillary teeth in ventral view, left side.

FIGURE 4. Map of southern portion of Colombia showing type locality (yellow star) of Creagrutus andaki.

FIGURE 5. Type locality of Creagrutus andaki, Colombia, Caquetá, Río Caquetá basin, Florencia, Río Hacha drainage, Río Sucre.