Ancistrus tolima, Taphorn, Donald C., Armbruster, Jonathan W., Villa-Navarro, Francisco & Ray, C. Keith, 2013

Taphorn, Donald C., Armbruster, Jonathan W., Villa-Navarro, Francisco & Ray, C. Keith, 2013, Trans-Andean Ancistrus (Siluriformes: Loricariidae), Zootaxa 3641 (4), pp. 343-370 : 360-364

publication ID

https://dx.doi.org/10.11646/zootaxa.3641.4.2

publication LSID

lsid:zoobank.org:pub:D9F4C67F-FE27-467B-B0DD-07A77E493538

DOI

https://doi.org/10.5281/zenodo.6157726

persistent identifier

https://treatment.plazi.org/id/0E26F513-DE3C-8463-FF1E-FC6BFBFA9B1E

treatment provided by

Plazi

scientific name

Ancistrus tolima
status

new species

Ancistrus tolima , new species, Taphorn, Armbruster, Villa-Navarro and Ray

( Figs. 10 View FIGURE 10 and 11 View FIGURE 11 )

Holotype: CZUT-IC 4040 (ex CZUT-IC 2083). Quebrada El Pescado, 3.599306 °, - 74.854556 °, 1187 masl, vereda San Pablo, municipio de Dolores, departamento de Tolima , Colombia.

Paratypes: CZUT-IC 2083, AUM 54491 (2) (ex CZUT-IC 2083), same as type locality.

Diagnosis. Ancistrus tolima can be diagnosed from all other trans-Andean Ancistrus by lacking an adipose fin membrane (adipose-fin spine completely adnate) and three to five preadipose plates (vs. usually one, occasionally two in most species and two to three in A. vericaucanus ); and from all other trans-Andean Ancistrus except A. vericaucanus by having the pectoral fin maximally reaching pelvic-fin spine when depressed ventral to pelvic fin (vs. pectoral fin reaching past middle of base of pelvic fin when depressed ventral to pelvic fin). Ancistrus tolima can further be separated from A. centrolepis by lacking one to three rows of enlarged odontodes on the lateral plates and no odontodes on lateral plates longer than half the width of the supporting plate (vs. rows of odontodes present with some odontodes almost as long as the supporting plate is wide); from A. galani by having fully developed eyes and pigment (vs. eyes reduced and pigment absent or reduced); from A. martini by having a head-eye length to snout length ratio of 71.2–91.9 % (vs. 53.9–73.9 %; Fig. 2 View FIGURE 2 C); and from A. vericaucanus by usually having four to five, occasionally three, preadipose plates (vs. two to three) and a dentary tooth cup length to SL ratio of 5.7–9.1 % (vs. 4.7–5.3 %; Fig. 2 View FIGURE 2 B).

Description. N= 10. Morphometrics given in Table 4 View TABLE 4 . Size range this study: 26–77 mm SL.

A relatively small Ancistrus , body broadest anteriorly, greatest body width just posterior to opercles, then narrowing progressively to end of caudal peduncle. Head and body depressed, greatest body depth between level of pectoral-fin insertions and dorsal-fin origin. Caudal peduncle deep, robust, compressed posteriorly. Dorsal profile of head ascending steeply in convex arc from tip of snout tip to just posterior of orbits, ascending in straight line to posterior tip of supraoccipital, then descending to dorsal-fin origin. From there, descending in gently convex arc to just posterior of dorsal-fin base, then straight to caudal fin. Ventral profile flat to slightly convex from tip of snout to pelvic-fin insertions, abdomen flat to slightly concave to pelvic-fin insertions, from there, straight to slightly convex and sloping gently ventrally towards caudal fin.

Head wide, interorbital width equal or slightly less than head depth, slightly less than half of head length. Snout rounded with large broad naked margin in males, less wide in females and juveniles. Snout length about onehalf head length. Eye moderate in size, interorbital area slightly convex. Oral disk ovate, wider than long. Lips covered with minute papillae, larger near mouth. Lower lip moderate in size, not reaching gill aperture, its border covered with very small papillae. Maxillary barbel very short, its length less than orbit diameter. Dentary tooth row straight, about same size as premaxillary tooth row. Teeth numerous (50–86 per jaw ramus), asymmetrically bifid, medial cusp much larger and spatulate, lateral cusp minute and pointed, usually not reaching more than half length of medial cusp, equal in worn teeth. Hypertrophied cheek odontodes strongly evertible, 13–23, stout with tips hooked anteriorly, bases encased in thick fleshy sheaths. Exposed part of opercle small, roughly triangular with few odontodes. Head smooth, bones on back of head not carinate; supraoccipital with margins between surrounding bones and plates usually clearly visible. Lateral plates not carinate, lateral line pores distinctly visible, horizontally elongate.

Ventral surface of head and abdomen naked, no exposed platelets anterior to anal-fin spine. Nuchal plate small and curved posterolaterally. No enlarged odontodes at edge of lateral plates. Five series of lateral plates anteriorly, three series on caudal peduncle, middorsal and mid-ventral plate series end on caudal peduncle beneath preadipose plate just anterior to embedded adipose-fin spine. Last plate in median series slightly smaller than penultimate plate, base of caudal fin with vertical column of about four small platelets after main series, and about six roughly triangular platelets covering bases of caudal-fin rays.

Dorsal-fin origin situated anterior to vertical through pelvic-fin insertion. First dorsal-fin ray not elongate, just slightly longer than snout length; last dorsal-fin ray reaching first preadipose plate when depressed. Adipose-fin spine (if present) embedded, oriented parallel to horizontal axis of body, membrane absent, not visible beneath spine. Pectoral spine short, stout, reaching past pelvic-fin insertions but only to anterior third of pelvic fins. Anal fin small but well developed; base of first anal-fin pterygiophore covered by skin, its origin below or posterior to vertical through base of last dorsal-fin ray. Pelvic fins reaching well past anal-fin origin, inserted posterior to vertical through first branched dorsal-fin ray. Caudal fin truncate, lower lobe slightly longer than upper.

Tiny odontodes present on body plates, largest on posterior margins of plates. All fin spines with small odontodes, more developed in pectoral-fin spine of males. All fin rays with tiny odontodes on rays.

Mid-dorsal plates 15 (1), 18 (2), 19 (6); median plates 23 (9); mid-ventral plates 17 (3), 19 (2), 20 (3), 21 (1); plates bordering dorsal-fin base 7 (8), 8 (2); plates between dorsal and adipose fins 3 (9), 4 (2), 5 (1); preadipose plates: 3 (4), 4 (3), 5 (5). Fin-ray formulae invariable (N= 7): dorsal i, 7; pectoral i, 6; pelvic i, 5; anal i, 4; caudal i, 14,i. Caudal procurrent spines: dorsal: 3 (1), 4 (3), 5 (6), ventral: 1 (1), 3 (9).

Color in alcohol. ( Fig. 10 View FIGURE 10 ) Base color brown or gray, often with lighter brown spots on soft nose and top of head. All fins with at least faint alternating dark and light (sometimes yellowish) spots present on spine and branched rays that align to form four-six curved, transverse bands alternating with rows of lighter spots on the dorsal, caudal, pelvic and pectoral fins, membranes dark brown, tips often blackish. Pale vertical bar at base of caudal fin narrow, sometimes absent. Ventral surface of head and abdomen tan to yellowish tan, oral disk whitish, plates of ventral surface of caudal peduncle with posterior margins darker brown, forming alternating light and dark pattern.

Life Colors. ( Fig. 11 View FIGURE 11 ) Dorsum dark olive green to brown with light green to yellowish spots (about one fourth orbit diameter in size) concentrated on soft nose, tentacles and top of head. Body posterior to dorsal-fin origin with fewer spots, and darker, almost black base color; posterior caudal peduncle (adjacent to caudal fin) with narrow light brown vertical bar. Preadipose plate and vestiges of adipose-fin spine outlined in yellow. Sides with irregular light spots, some forming horizontal rows. Ventrum of body not observed in live specimens. Oral disk and adjacent area on chest pink to whitish. Fin membranes darkly pigmented, almost black, but spines and rays marked with four-six alternating dark olive green or blackish and whitish or light green sections. Caudal fin spine and rays with alternating light and dark sections often aligned to form three-four vertical arcs.

Distribution. Upper Magdalena River drainage, subdrainage río Prado, Tolima , Colombia.

Etymology. tolima is a noun in apposition, and refers to the princess Yulima who was executed and martyred by the Spanish conquistadores, and to the Department of Tolima , where the type locality is located.

Remarks. El Pescado creek has a sand and gravel substrate, abundant allochthonous organic material, and steep banks with little shoreline vegetation. The average depth of the type locality is 0.5 m. It is a small tributary of Quebrada Aco, which used to flow into the Negro River. However, since the construction of the El Prado reservoir, Quebrada Aco empties directly into the lake, which is located on the western flank of the Cordillera Oriental of the Colombian Andes, in the Department of Tolima , upper Magdalena River drainage.

TABLE 4. Selected morphometrics of Ancistrus tolima and A. vericaucanus.

  A. tolima (n=11) A. vericaucanus (n=10)
  Mean SD Range Mean SD Range
SL (mm) 45.5* 26.7–77.1 56.5 43.2–72.1
%SL    
Predorsal Length 46.7 1.5 44.2–49.6 47.3 2.3 45.0–51.9
Head Length 38.4 1.7 35.5–40.7 36.8 1.6 34.3–39.4
Head-dorsal Length 9.1 1.2 7.2–10.6 11.0 0.6 10.0–11.8
Cleithral Width 33.5 0.7 32.6–34.8 31.6 1.7 30.1–35.4
Head-pectoral Length 28.2 1.3 26.2–30.2 27.4 1.3 25.4–29.4
Thorax Length 25.0 1.1 23.6–27.0 25.1 2.2 22.1–28.8
Pectoral-spine Length 24.6 1.7 21.8–27.4 25.0 1.6 21.8–26.8
Abdominal Length 22.5 1.5 20.4–24.9 21.4 1.0 19.6–22.6
Pelvic-spine Length 22.4 1.9 19.8–25.4 23.3 2.1 19.8–26.0
Postanal Length 30.8 2.0 28.9–35.7 32.7 1.6 30.0–35.3
Anal-fin spine Length 9.8 1.2 8.0–12.9 12.1 1.2 9.8–13.7
Dorsal-pectoral Distance 29.2 1.1 27.8–31.3 30.3 1.0 28.3–31.9
Dorsal spine Length 25.0** 1.4 22.2–26.9 24.7 1.5 20.8–26.3
Dorsal-pelvic Distance 19.9 2.2 16.7–22.3 21.6 1.5 18.5–23.3
Dorsal-fin base Length 21.0 1.1 19.3–23.0 20.4 1.3 18.2–22.0
Dorsal-adipose Distance 20.7 2.2 17.6–25.5 20.9 2.5 17.7–24.3
Adipose-spine Length 7.2 2.8 3.9–12.9 7.3 1.3 5.5–9.3
Adipose-upper caudal Distance 13.0 2.3 10.2–15.9 15.4 1.2 13.8–17.3
Caudal peduncle Depth 9.2 0.9 7.7–10.5 9.3 0.7 8.2–10.3
Adipose-lower caudal Distance 19.0 1.9 16.3–21.5 19.5 0.9 18.1–21.4
Adipose-anal Distance 20.9 1.8 18.5–24.0 21.3 1.3 19.4–23.1
Dorsal-anal Distance 13.8 0.8 12.5–14.9 15.9 0.8 14.5–16.9
Pelvic-dorsal Distance 23.1 2.0 18.0–25.3 23.3 1.1 21.2–24.8
% Head Length    
Head-eye Length 43.8 3.6 35.6–46.4 45.3 1.9 41.9–48.8
Orbit Diameter 15.9 2.2 11.7–18.7 15.1 1.9 12.5–18.4
Snout Length 51.4 1.5 49.5–53.8 54.9 2.7 51.7–59.8
Internares Width 13.5 1.7 11.7–17.8 18.0 1.0 16.1–19.2
Interorbital Width 53.2 2.8 47.8–56.8 55.2 2.1 53.2–60.3
Head Depth 63.4 2.5 59.8–67.2 66.7 2.0 63.3–69.1
Mouth Length 41.3 4.0 36.7–48.6 44.0 2.2 39.9–47.8
Mouth Width 50.8 5.2 44.7–62.5 48.0 3.6 42.2–53.7
Barbel Length 4.0*** 1.3 1.9–6.2 3.4 0.8 2.6–5.1
Dentary tooth cup Length 18.2 2.4 14.2–23.4 13.4 0.7 12.7–14.8
Premaxillary tooth cup Length 16.7 2.0 13.1–19.7 13.5 1.7 11.8–16.1
n=13, **n=8, ***n=10