Parodon pongoensis (Allen, 1942)

Londoño-Burbano, Alejandro, Román-Valencia, César & Taphorn, Donald C., 2011, Taxonomic review of Colombian Parodon (Characiformes: Parodontidae), with descriptions of three new species, Neotropical Ichthyology 9 (4), pp. 709-730 : 723-725

Parodon pongoensis (Allen, 1942)

Fig. 9

Apareiodon pongoense Allen , in Eigenmann & Allen, 1942: 286 (type locality: Pongo de Manseriche , Marañón River drainage, Perú, Holotype: CAS 6757 ). Ortega & Vari, 1986: 11 (distribution; records from collections). Starnes & Schindler, 1993:757 (jaw bone illustration, comments).

Apareiodon caquetae Fowler, 1945a: 106 (type locality: Morelia , Rio Caquetá drainage, Colombia; comments; lateral view illustration; Holotype: ANSP 71696 ). Starnes & Schindler, 1993: 755 (comments).

Parodon caquetae .- Böhlke, 1958: 85 (comments; tables with morphometric data). Wiley & Collette, 1970: 166 (nuptial tubercles).

Parodon pongoense .- Géry, 1977: 203 (key; distribution; synonymy with A. caquetae ; photograph of two live individuals).

Parodon pongoensis . - Pavanelli, 2003: 48 (synonymy; distribution; localization of type material; maximum size; common names).

Diagnosis. Parodon pongoensis differs from all congeners in having a well-defined lateral stripe without dorsal or ventral projections (vs. lateral stripe with diffuse margins and dorsal and ventral projections, or no lateral stripe), except from P. moreirai , from which it can be differentiated by the lower number of scales on the lateral line (34-38 vs. 40-42) and the normal size of maxillary teeth (vs. absence or minuteness of the teeth); by the presence of a black spot on the lower caudalfin lobe (vs. no spot on lower caudal-fin lobe); can be distinguished from P. guyanensis by the presence of four premaxillary teeth (vs. five).

Description. Morphometric and meristic data given in Tables 3 and 4, respectively. Body stout. Dorsal profile of trunk straight from tip of snout to dorsal-fin origin, where angle deflects and continues straight to adipose fin, then concave to caudal fin. Ventral profile of head straight to isthmus, located at vertical through anterior part of opercle. Branchial membranes united to each other but not to isthmus. Eyes lateral; nares at level of eye, membrane of skin present but neither projected nor separating orifices into separate halves. Mouth ventral, upper lip absent. Ventral trunk profile generally rounded from isthmus to pelvic fin insertions then straight to caudal fin. Caudal peduncle compressed.

Premaxillary hemiseries with four teeth that have irregular rounded margins; with 9-12 prominent cusps thicker than in congeners; teeth fitting into space in lower jaw. Maxilla with 2-3 multicuspid teeth, smaller than those of premaxilla, and usually half covered by surrounding soft tissue. Lower jaw with 1-3 unicuspid, lateral teeth outwardly curved and not visible when mouth closed.

Pectoral fin short, not reaching pelvic-fin insertions. Truncate shaped pectoral fins inserted at vertical passing through second predorsal scale posterior to supraoccipital tip, fourth to sixth branched rays longest. Pelvic fin not reaching anal-fin origin, sometimes reaching but not surpassing genital pore. Pelvic fin at vertical through base of dorsal fin. Dorsal fin truncate, first two branched rays longest, its origin at vertical through second scale anterior to pelvic fin insertion. Anal fin at vertical through first or second scale anterior to adipose fin. Anal fin tip not reaching caudal fin. Adipose fin not reaching caudal fin; its origin at vertical through posterior margin of anal-fin base. Caudal fin bilobed, upper lobe longer, basal third covered with scales.

Lateral line with 34-38 pored scales, extended onto caudal fin. Predorsal and ventral scales regularly distributed.Axillary scale present, one or two normal scales in length.

Color in alcohol. Dorsal part of snout and head black, base color of head white or yellow below middle of eye; white spot on upper part of opercle (absent in one specimen). Dorsum of body black, just slightly lighter than lateral stripe, with diffuse white or yellow spots not forming rows or transverse bands. Two black dorsal stripes one half to one scale in width, delimiting dark dorsum, originate lateral to supraoccipital process tip and unite just posterior to adipose fin.

Body base color white to yellow, with well defined black lateral stripe that lacks dorsal or ventral projections and that initiates on snout at level of eye and continues to tips of middle caudal-fin rays. Above this black stripe three diffuse black spots; first at vertical through pectoral fin insertions, second at vertical through pelvic-fin insertions, and third at vertical through anal-fin origin.

Pectoral fin with few almost imperceptible diffuse black chromatophores. Pelvic and anal fins hyaline. Dorsal fin with chromatophores concentrated on second unbranched ray. Caudal fin with middle rays black to tips, sparse black chromatophores present on both lobes, but concentrated on lower lobe to form well defined spot. Ventral part of body same color as rest, without spots, stripes or bars.

Sexual dimorphism. Not observed, perhaps because of time of collection, or juvenile estate of specimens examined. Wiley & Collette (1970) reported nuptial tubercles in adult males.

Distribution. MiddleAmazonas on Putumayo River drainage in Colombia; upper Amazonas in Peru ( Fig. 2 ).

Comments. According to the original description, Parodon pongoensis has 49 scales in the lateral line, very different from our count. However, in the holotype we count 39 scales, suggesting that the count published by Allen (in Eigenmann & Allen, 1942) may have been just a typographical error. His counts of scales above and below the lateral line coincide with ours (4-5).

Fowler (1945a) described Apareiodon caquetae from the Caquetá River in Colombia, but those specimens coincide in many aspects with P. pongoensis . We examined specimens from near the type locality of A. caquetae to shed light on the validity of that name. Fowler stated that A. caquetae had “On caudal also diffuse dark bar at bases of lower rays”, a color pattern like that of P. pongoensis , referring to the round, dark spot on the lower caudal lobe, present on both P. pongoensis and A. caquetae . Fowler gave the number of lateral line scales as 33+3 and his illustration (fig. 6. p. 104) would seem to show a typical P. pongoensis . Fowler (1945a) stated “the round pale spot, about the size of the pupil, imposed on the black lateral band at the upper part of the opercle.” We observed that there is a white spot on upper part of the opercle, that even though it was observed in the majority of specimens here examined, is not so evident as might be indicated by Fowler’s illustration, but could be effect of fixation. We maintain the synonymy of A. caquetae with P. pongoensis , in agreement with Pavanelli (2003), Böhlke (1958) and Starnes & Schindler (1993), on the basis of color pattern and meristics.

Starnes & Schindler (1993) illustrated the jaw bones and part of the suspensorium of a specimen identified as “ A. pongoense ” (USNM 216400), but did not show teeth present on the lower jaw. In any case, according to our findings, in specimens smaller than 50 mm SL the dentary teeth are often covered by soft tissue or reduced and not easily visible. Thus, due the small size of this specimen, 43 mm SL, this feature may have been overlooked by the authors and not illustrated. So the illustration should not be taken as indicative of the condition for this species.

Böhlke (1958) discussed Fowler’s (1945a) Apareiodon caquetae (= Parodon pongoensis ), and identified it as P. caquetae based on the characters that traditionally have been used to separate the genus Apareiodon and Parodon : “ Apareiodon is in all respects like Parodon except that there are no teeth in the side of the lower jaw. The ampulla on the upturned edge of the lower jaw, with which the teeth are associated in Parodon , is less well developed in this genus ( Eigenmann, 1916)”. When Böhlke (1958) examined Fowler’s specimens, he found teeth present on the dentary just as we have found them in specimens from sites in the Caquetá River drainage, near the type locality of A. caquetae . In any case, this species is also a synonym of P. pongoensis since P. caquetae and A. caquetae are the same species.

Material examined. Peru. CAS 6757 , holotype of Apareiodon pongoense , 62.0 mm SL, Puerto Melendez, upper Amazon, Pongo de Manseriche , small woodland stream opposite . AMNH 217981 , 1 , 66.8 mm SL, Iquitos, Loreto, Iquitos, upper río Amazonas . Colombia. SU 50671 , 15 , 41.1 -48.0 mm SL, Caquetá, río Amazon basin, small stream across the río Orteguaza from Tres Esquinas (same streams as sta. 1) . SU 53673 , 4 , 51.3 -71.0 mm SL, Caquetá, río Amazon basin, upper río Orteguaza , Puerto Lara near Florencia . IUQ 2085 , 1 , 43.9 mm SL, Putumayo, Puerto Leguizamo , río Putumayo, 00°11’S, 74°47’W . ICN 15380, 1 , 56.8 mm SL, Putumayo, Pto. Leguizamo, río Putumayo . ICN 15378, 1 , 45.9 mm SL, Putumayo, Pto. Leguizamo, downstream Puerto Leguizamo in front of S.B Yaricaya, C. Yaricaya, río Putumayo drainage . Ecuador. BMNH 1981. 1. 5. 603-606, 4, 43.0- 50.3 mm SL, río Amazon basin, upper Amazon .

Figures

Fig. 9. Parodon pongoensis, ICN 15378, 45.9 mm SL, Colombia, Amazon River Basin, downstream from Puerto Leguizamo, Fuerte. S.B de Yaricaya, C. Yaricaya, Putumayo River drainage, Putumayo.

Fig. 2. Distribution of Parodon species in Colombia. Parodon apolinari (star); P. buckleyi (square); P. caliensis (diamond); P. pongoensis (pentagon); P. suborbitalis (circle); P. alfonsoi (arrow up); P. magdalenensis (triangle); P. atratoensis (X). Each symbol may represent more than one locality. Open symbols represents type locality of each species.