Parodon magdalenensis, Londoño-Burbano & Román-Valencia & Taphorn, 2011

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 : 721-723

Parodon magdalenensis , new species

Fig. 8

Parodon suborbitale .- Miles, 1943: 132 (key; distribution; synonymy). Dahl, 1971: 116 (key; illustration in lateral view, distribution, comments).

Parodon suborbitalis .- Eigenmann, 1922: 108-109 (key; synonymy; distribution; lateral view illustration). Fowler, 1945b:2 (record from Tolima Department, Colombia). Maldonado et al., 2005: 39; 255; 301 (lateral view illustration, synonymy, common names, conservation status, description, biology, distribution, comments, museum records).

Parodon caliensis .- Cardona et al., 1998: 11-24 (presence in Cauca River basin).

Holotype. ICN 17099, 108.6 mm SL, Colombia, Caldas, Norcasia, middle río Magdalena drainage, río La Miel at escape tunnel, río Magdalena, 5°34’N, 74°53’W, elevation 720 masl, 26 Mar 2006, P. Sánchez & L. M. Mesa.

Paratypes. Colombia. ICN 16089, 6 , 59.7-106.9 mm SL, collected with holotype . IUQ 2547 , 2 c&s, 73.2-100.1 mm SL, collected with holotype . IUQ 2221 , 7 , 45.0- 65.2 mm SL, and IUQ 2385 , 1 c&s, 60.4 mm SL, Caldas, Samaná, middle río Magdalena drainage, río La Miel at confluence with río Tasajos , 5°24’N, 74°59’W, 1416 masl, 4 Sep 2006, U. Jaramillo . IUQ 2367 , 1, 126.9 mm SL, Valle del Cauca, río Frío drainage, upper río Cauca, río Portugal de Piedras , lower section station 001, 4°03’N, 76°18’W, 2 Oct 2008, J. Anderson & M. Ramirez . IUQ 2376 , 2 , 108.4 - 114 mm SL, Valle del Cauca, río Frío drainage, upper Cauca, río Portugal de Piedras , lower section, 4°03’N, 76°18’W, 11 Nov 2008, H. M. Ramirez, & A. Arcila . ICN 16272; 13 + 2 c&s, 33.7-74.3 mm SL, Caldas, middle río Magdalena drainage, río Samaná , 5°24’N, 74°59’W, 1416 masl, 1 May 2006, P. Sánchez & L. M. Mesa . IUQ 1238 , 1, 109.6 mm SL, Valle del Cauca, La Paila, upper Cauca, río La Paila 200 m below bridge on La Paila-Tulua highway, 4°19’N, 76°03’W, 937 masl, Mar 2000, C. Román-Valencia et al . IUQ 1683 , 1 , 49.7 mm SL, Valle del Cauca, Zarzal, upper Cauca, Las Cañas creek, tributary of río Cauca, road to Zarzal , 4°21’N, 76°04’W, 6 Aug 2007, C. Román- Valencia, J. Vanegas-Rios, & A. Londoño-Burbano . IUQ 568 , 2 , 53.4-85.4 mm SL, Valle del Cauca, upper Cauca, San Pablo Creek , 4°23’N, 76°04’W, 13 Sep 1996, M. Cardona, & J. L. Jimenez .

Non types. Colombia. ICN 11491, 25 , 34.8-61.2 mm SL, Caldas, La Dorada, middle río Magdalena drainage, bridge on Honda-La Dorada road, río Guarino , 20 Feb 2005 . ICN 2031 , 3 , 70.6-88.5 mm SL, middle río Magdalena drainage, oil pipe road Colombia-Línea Base, San Juan de Bedout Creek , May 1992 . IUQ 2225 , 2 , 45-47.8 mm SL, middle Magdalena drainage, overflow of Amaní Reservoir, border between Victoria and Samaná , 30 Nov 2007 . IUQ 1051 , 1 , 57.0 mm SL, upper río Cauca drainage, río Chanco , tributary of río Cauca, Ansermanuevo, 17 Jun 2000 .

Diagnosis. Parodon magdalenensis differs from all congeners by presenting a completely dark ground portion above black lateral stripe that lacks projections or spots extending dorsally, in adults (vs. base color white to yellow above lateral stripe which often has projections or spots extending dorsally); base color below lateral stripe to level of axillary scale gray (vs. body below lateral stripe same color as base color of rest of body, usually white or yellow); adults with well defined black spot from middle of pectoral fin to its tip (not reaching base), absent in juveniles (vs. chromatophores present on pectoral fin not forming well-defined spot, nor bar and often present in juveniles); no dark brown spots on dorsal part of sides above lateral stripe (vs. dark brown spots present); branched pectoralfin rays 11-14 (vs. 14-16; except P. buckleyi which has 13-15 branched pectoral rays). Parodon magdalenensis differs from P. bifasciatus by the higher number of cusps in premaxillary teeth (11-15 vs. 7-12) and the lower number of post-adipose scales (6-8 vs. 7-10, as well as from P. hilarii and P. nasus which have the same count as P. bifasciatus ). It is differentiated from P. guyanensis by the number of teeth on the premaxilla (4 vs. 5) and can be distinguished from P. pongoensis and P. moreirai by the presence of a lateral band with projections above and below (vs. absence of projections in such band) and the number of scales in the lateral line (35-38 vs. 40-42 in P. moreirai ), and normal sized teeth in the maxilla (vs. teeth minute or absent). It can be distinguished from most P. carrikeri by the number of scales in the lateral line (35-38 vs. 38-39), and the dark coloration along the body including most of the head (vs. ground and general color of body light in P. magdalenensis ). It differs from P. suborbitalis by the lower number of cusps in premaxillary teeth (11-15 vs. 15-17).

Description. Morphometric and meristic data given in Tables 1 and 2, respectively. Body stout. Dorsal profile of body convex from snout to dorsal-fin origin, then straight to four scales anterior of caudal-fin, then concave to caudal fin. Ventral profile of head straight from snout to isthmus; isthmus at vertical through anterior part of opercle; branchial membranes united to each other but not to isthmus. Eyes lateral; lateral groove present from tip of snout to anterior margin of nares; nares at level of eye, rounded, membrane present but not projecting nor separating orifices into separate halves. Mouth ventral, upper lip absent. Ventral profile of body round from isthmus to anal-fin origin then concave to caudal fin. Caudal peduncle compressed.

Premaxillary hemiseries with four teeth; maxilla with two. Lower jaw with 2-3 lateral teeth. Premaxillary teeth arranged in straight line, each with straight inferior margin laterally with curved portion that includes one or two cusps, total cusps 11-15. Teeth fit into space to receive them in lower jaw. Lower jaw with 1-3 unicuspid, outwardly curved, lateral teeth, best observed in adults, in juveniles often covered by soft tissue and poorly developed, not visible when jaws closed. Maxillary teeth 1-3, smaller than those of premaxilla, multicuspid, often covered by soft tissue.

Pectoral fin short, not reaching pelvic-fin insertions, located at vertical through opercular membrane, truncate in shape with third to fifth branched rays longer than rest. Pelvic fin not reaching anal fin; reaching, but do not surpassing, genital pore in individuals below 80 mm SL. In larger specimens pelvic fins fall one scale short of genital pore, first two branched rays longer than remaining. Pelvic fin at vertical through middle of dorsal-fin base. Anal fin truncate, at vertical through point three scales anterior to adipose fin, with first two branched rays longer than remaining, but not reaching caudal fin. Dorsal fin truncate, second unbranched and first branched rays longest, origin located at vertical through point half way between pectoral and pelvic insertions. Its posterior tip not reaching vertical through tips of pelvic fin, and falling short of adipose-fin origin by six scales. Adipose fin with dark base, origin at vertical through posterior portion of anal fin. Caudal fin bilobed, upper lobe longer than lower, its proximal third heavily covered with scales. In specimens over 100 mm SL, scales extend even further on fin.

Lateral line complete, with 35-38 pored scales, sometimes extending onto base of caudal fin. Predorsal and ventral regions with scales arranged regularly. Axillary scale present, about one or two normal scales in length.

Color in alcohol. Dorsal surface of snout and head black, white or dark yellow below middle of eye. Dorsum darker than rest of body, including lateral stripe. Base color gray (much lighter in juveniles) sometimes very dark yellow, mainly in specimens from La Miel River (Magdalena River drainage). Lateral stripe present above lateral line from snout to tips of middle caudal-fin rays; juveniles (34.8-74.3 mm SL) with 8-12 dorsal and ventral projections (about two scales in width) forming zigzag, more conspicuous anterior to vertical through dorsal-fin base; in some specimens below 80 mm SL lateral stripe lacks dorsal projections; downward projections reach only one scale below lateral stripe; sometimes stripe with neither dorsal nor vertical projections. Some individuals below 80 mm SL with 2-3 spots above lateral stripe over white or yellow base color. Some adults over 80 mm SL with lateral stripe totally diffuse, without showing any clearly defined borders or projections. Sides of body gray below lateral stripe to level of axillary scale, but of totally different shade from gray on head. Above lateral stripe no lighter colored area present, but some small gray blotches present that blend with dark base color of dorsum. Two darker stripes present along either side of supraoccipital process, above opercle.

Adults with distal black blotch on first five rays of pectoral fin, not obvious in juveniles. Chromatophores on first two rays of pelvic fin little developed and not forming well defined spot, hyaline in juveniles. Anal fin hyaline. Dorsal fin with very conspicuous black chromatophores on distal portion, first unbranched ray completely dark, but fin without well defined spots or bars. Adipose fin with black base. Ventral portion of body lighter than rest, without spots or chromatophores.

Sexual dimorphism. Nuptial tubercles almost imperceptible, even on ventral region of snout, very small and few in number, present in males over 85 mm SL.

Distribution. Known from the La Miel River and its tributaries in middle Magdalena drainage, the Paila River system and tributaries of the upper Cauca River, Colombia ( Fig. 2 ).

Etymology. The name magdalenensis refers to the Magdalena River, Colombia, in which this species is endemic.

Comments. Parodon magdalenensis is a member of the Parodon suborbitalis species group. It has the principal characteristic of the species of that group: a dark, lateral horizontal stripe with dorsal and ventral projections.Although Mago-Leccia (1970) proposed a close relationship among populations of fishes of the Lake Maracaibo basin and those of the Magdalena River basin before the rise of the Perija Mountain range, we present evidence for specific differentiation of the P. suborbitalis (Maracaibo) from those of the Magdalena. We assume that records of Eigenmann (1922), Dahl (1971) and Miles (1943) for P. suborbitalis from the Magdalena are P. magdalenensis . Specimens examined in this study from localities near those cited by them indicate that P. suborbitalis is not present in that system.

Eigenmann (1922) showed a figure of a 43 mm SL specimen (plate XIX-1) identified as P. suborbitalis from Peñas Blancas, in Antioquia, that does not show projections from the lateral stripe, but does not give counts of premaxillary tooth cusps. We examined a 48.9 mm SL specimen from the Miel River, Antioquia Department (IUQ 2224), that shows the same characteristics present in Eigenmann’s specimen, that is, a lateral stripe without projections, and spots above that reach to dorsum. Furthermore, our specimen has a lower number of premaxillary tooth cusps in comparison to specimens from the middle Magdalena and upper Cauca sites (9 vs. 11-15), as well as a higher pored lateral-line scale count (39 vs. 35-38), and also to the specimens examined by Eigenmann (1922) from Peñas Blancas, which have 35-37 lateral scales. For these reasons, this specimen is identified as Parodon sp. and was not included in the analysis. Even though this specimen shares some diagnostic characters with P. pongoensis (a well-defined lateral stripe without dorsal or ventral projections vs. ill defined lateral stripe), we do not believe that it belongs to that species. It has 39 lateral scales, and the known range for P. pongoensis is 34- 38. In addition, P. pongoensis has a black spot on the distal portion of the caudal rays on the lower lobe which our specimen lacks.Also, so far P. pongoensis is known only from theAmazon basin. Therefore, we conclude that the specimen IUQ 2224 is from the same population examined by Eigenmann (1922), but that it is neither P. suborbitalis nor P. pongoensis .

Cardona et al. (1998) reported on specimens of P. caliensis . However, we examined two specimens collected by those authors, and found them to have a color pattern totally different from that described for P. caliensis , which includes a lateral stripe with projections of less than one half scale length in width (vs. vertical bars on sides of body, and without horizontal lateral stripe in P. caliensis ), and differing meristic counts: pored lateral line scales are 36-37 in P. magdalenensis vs. 39-40 in P. caliensis . We identify the specimens we examined collected by those authors as P. magdalenensis .

Figures

Fig. 8. Parodon magdalenensis, Holotype, ICN 17099, 108.6 mm SL, Colombia, Caldas, Norcasia, La Miel River at escape tunnel, middle Magdalena River drainage.

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.