HYPHESSOBRYCON NATAGAIMA ( CHARACIFORMES : CHARACIDAE ) A NEW SPECIES FROM COLOMBIA , WITH A KEY TO THE MAGDALENA BASIN HYPHESSOBRYCON SPECIES Hyphessobrycon natagaima ( Characiformes : Characidae ) una nueva especie para Colombia , con clave para las especies

A new species, Hyphessobrycon natagaima, is described from the upper Magdalena River Basin in Colombia. It differs from all other species of Hyphessobrycon with a dark lateral stripe inhabiting the Magdalena River Basin: H. poecilioides, H. proteus and H. ocasoensis, by having eight to twelve pored lateral-line scales (vs. 14-26); four scales between the lateral line and the pelvic-fin insertions (vs. five or six); one tooth on the maxilla (vs. zero in H. poecilioides, and two to five in H. proteus; except H. ocasoensis, with one), a dark, interrupted, lateral stripe that is not in contact with the caudal peduncle spot (vs. absence of caudal spot in H. poecilioides, lateral stripe continued that is in contact with the caudal peduncle spot in H. ocasoensis). It has a rhomboid shaped caudal-peduncle spot that continues on to middle caudal-fin rays (vs. absence of caudal peduncle spot in H. poecilioides and caudal peduncle spot round and not continued on to middle caudal-fin rays in H. ocasoensis); and presence of hooks on all fins in mature males (vs. males with hooks on anal, pelvic and pectoral fins). Hyphessobrycon natagaima differs from H. ocasoensis, in addition to the above characters, by having four scale rows between the lateral line and the anal-fin origin (vs. six); three or four scale rows between the lateral line and the pelvic-fin insertions (vs. six); ten or eleven predorsal scales (vs. nine); i,9,i dorsal-fin rays (vs. ii,8,i); 18-20 branched anal-fin rays (vs. 21-22) and eleven branched pectoral-fin rays (vs. twelve). A key for the identification of Hyphessobrycon species present in the Magdalena River Basin is provided. doi: http://dx.doi.org/10.15446/caldasia.v37n1.51228 http://ciencias.bogota.unal.edu.co/icn/publicaciones/ Hyphessobrycon natagaima a new species from Colombia


INTRODUCTION
Hyphessobrycon is a genus of small fishes known for their beauty and color, and they are widely desired by aquarists.Although Hyphessobrycon is usually treated as a valid genus (Durbin in Eigenmann 1908, Eigenmann 1917, 1918, 1927, Géry 1977, García-Alzate et al 2008a), it remains poorly defined and is polyphyletic.No modern hypothesis of phylogenetic relationships exists for all species of the genus, and the characters traditionally used to define species have not been analyzed in a phylogenetic perspective, often leading to misinterpretation of those characters.Current phylogenetic hypotheses for Characidae (Mirande 2010, Oliveira et al 2011) include some species of Hyphessobrycon, and recognize that the genus is not monophyletic.However, those works did not include the type species, Hyphessobrycon compressus (Meek), which is a species from the northernmost extreme of the range of this genus, in Mexico.

MATERIALS AND METHODS
Fishes were captured using seines and were preserved in situ with 10% formalin and later stored in 70% ethanol.Measurements and counts follow Fink & Weitzman (1974).Measurements were made with digital calipers to 0.01mm precision and are expressed as percentages of standard (SL) and head length (HL).In count ranges, values for the holotype are indicated with an asterisk (*).Counts and measurements were taken on the left side of specimens when possible.Osteological observations were made on cleared and stained specimens (C&S) prepared according to Taylor & Van Dyke (1985) and Song & Parenti (1995).Bone nomenclature follows Weitzman (1962) and Vari (1995) Rivers, 1913. BMNH 1913.10.1.19-21, 25.9-31.2Etymology.Hyphessobrycon natagaima is in reference to the Amerindian people who have inhabited the region where this new species was found.The legend relates that a chief Nataga and a princess Aima were married to originate the tribe.
Ecology.The Laguna Saldañita wetland, habitat of new taxon, is characterized by riparian vegetation consisting of grasses and rooted and floating aquatic vegetation.
Remarks.These taxa, cited below, are in evident allopatric distribution.In addition,principal component analysis revealed differences among H. natagaima and H. poecilioides, H. proteus and H. ocasoensis along the first axis (PC1) related to the distance from the dorsal-fin origin to the hypurals, dorsal-fin length, and the length of the maxilla.On the second axis, the snoutpelvic-fin insertion distance, head length, upper jaw length and caudal peduncle depth were the variables explaining the observed variation.And on the third axis, caudal-peduncle length, and upper jaw length were important.The first axis explained 84.87% of variation; the second 11.31%, and the third 2.57 for a total of 98.75% (Fig. 4).

Figure 2 .
Figure 2. Hyphessobrycon species distributed in the Magdalena River Basin, Colombia.Scale bar= 1 cmFirst gill arch with 20 rakers, three on hypobranchial, ten on ceratobranchial and seven on epibranchial.Proximal pterygiophores of dorsal-fin rays inserted between neural spines nine to 16; anal-fin with 21 proximal pterygiophores, the first two inserted between hemal spines eleven and twelve, reaching ventral border of centrum of hemal spine twelve.Five elongate supraneurals with cartilage on upper and lower tips, inserted over fourth to ninth neural spines.Sexual dimorphism.Males with hooks on all fin rays, two pairs of eight small hooks on fourth unbranched anal-fin ray, two to eight pairs of hooks from first to seventh branched anal-fin rays.Two to ten pairs of hooks on branched pelvic-fin rays, located on internal branch of the ray.Pectoral-fin rays with two to eight pairs of hooks on first and eighth branched rays.Dorsal-fin with small hooks on distal tip of anterior rays.Caudal-fin with one to four small hooks on middle rays.

Figure 3 .
Figure 3. Hyphessobrycon natagaima n. sp., UARC-IC 360, paratype, 34.7 mm SL.P premaxilla (A), maxilla (B) and dentary (C), left side.Bar = 1 mm Color in alcohol.Body light brown, dorsum dark brown.Conspicuous, rhomboidal caudal peduncle spot extends on to middle caudal-fin rays.Flanks with dark stripe, posteriorly to humeral spot, interrupted and not in contact with caudal-peduncle spot, deeper at vertical through dorsal-fin origin.Dark humeral spot , vertically elongate, covering two scales below pored lateral-line.Posterior margin of scales with dark cromatophores.Edges of dorsal and caudal fins dark.Pectoral, pelvic and anal fins hyaline; anal fin with dark cromatophores on membranes.Top of head dark brown (Fig. 2).Distribution.Hyphessobrycon natagaima is known from Laguna Saldañita and Laguna El Hato, upper Magdalena river drainage, Tolima.Etymology.Hyphessobrycon natagaima is in reference to the Amerindian people who have inhabited the region where this new species was found.The legend relates that a chief Nataga and a princess Aima were married to originate the tribe.
Taxonomia, Neotropical, especie nueva, biodiversidad.H. sebastiani García-Alzate, Román-Valencia & Taphorn 2010, H. saizi Géry 1964, and H. taguae García-Alzate, Román-Valencia & Taphorn 2010.Three of these are distributed in the basin of the Magdalena River basin: H. poecilioides, H. proteus and H. ocasoensis.The objective of this paper is to describe a new species from the Magdalena River Basin in Colombia, part of the results of the ongoing systematic review of the genus Hyphessobrycon by the first author.

Table 1 .
Morphometric data for Hyphessobrycon natagaima n. sp.Standard and total length in mm, average in parentheses.SD = standard deviation.N = 46