Abstract

The genus Hyphessobrycon is included within the subfamily Tetragonopterinae. The species are generally small, do not exceed 70mm of standard length, are economically important as ornamental fish, with 128 valid species distributed from Southern Mexico to Rio La Plata in Argentina. The collections of fish were made with seines, in a single biotope, along shore in backwaters and working downstream. Measurements of the specimens were taken point to point with digital calipers. Observations of bone and cartilage structures were made on cleared and stained (C&S) specimens. The morphometric relationships between species were explored using a principal component analysis (PCA)using 21 variables. We described a new species, Hyphessobrycon chocoensis, from the Telembi River drainage of the Pacific versant of Colombia. The new species, Hyphessobrycon chocoensis, is distinguished from congeners not of the "flammeus" species group by: having a diffuse humeral spot, in lacking a dark spot on the dorsal fin and caudal peduncle. It is distinguished from members its species group by the number of rays in the dorsal fin (ii, 8, i), by the number of branched anal-fin rays (25-26) and by having a diffuse humeral spot. It differs from H. tortuguerae in the number of teeth on the maxilla (1-2), by the number of predorsal scales and the high number of scales between the lateral line and the anal fin (6-7). Hyphessobrycon chocoensis can be distinguished from the other known species of Hyphessobrycon from the Pacific Coast of Colombia in having: a high number of pored lateral-line scales, by the snout to dorsal-fin length, by caudal-peduncle depth and by eye diameter. In addition, it differs from H. columbianus by the distance from the dorsal fin to the anal fin, by the length of the upper jaw, and by snout length. It differs from H. condotensis in having a high number of scales between the lateral line and the dorsal fin, and by the number of simple rays in the anal fin. H. chocoensis is distinguished from H. sebastiani by the number of transverse scales and the number of scales between the lateral line and the dorsal fin. A taxonomic key is provided to aid with the identification of the species of Hyphessobrycon from the Pacific Coast of Colombia.

Highlights

  • Aunque 157 especies han sido ubicados en Hyphessobrycon, debido al reconocimiento de sinónimos o la reubicación de algunas especies en otros géneros, hoy se consideran válidas 128 especies (Eschmeyer & Fricke 2011)

  • En Hyphessobrycon aun no existe un consenso para la definición de clados filogenéticos, sin embargo, se han reconocido seis grupos convenientes, pero artificiales, de especies basados en modelos de pigmentación (Géry 1977, Weitzman & Palmer, 1997)

  • Las observaciones de estructuras óseas y cartílagos se hicieron sobre ejemplares clareados y teñidos (C&T) de acuerdo a los métodos descritos por Taylor & Van Dyke (1985) y Song & Parenti (1995)

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Summary

Introduction

Aunque 157 especies han sido ubicados en Hyphessobrycon, debido al reconocimiento de sinónimos o la reubicación de algunas especies en otros géneros, hoy se consideran válidas 128 especies (Eschmeyer & Fricke 2011). Se distingue de las demás especies del grupo por el número de radios de la aleta dorsal (ii, 8, i vs iii, 8; ii, 9), por el número de radios ramificados en la aleta anal (25-26 vs 15-24; excepto H. sebastiani con 25-28) y por presentar la mancha humeral difusa (vs una o dos manchas humerales bien definidas), se diferencia de H. tortuguerae por el número de dientes en el maxilar (1-2 vs 3-10), por el número de escamas predorsales (10-12 vs 13-15) y un alto número de escamas entre la línea lateral y la aleta anal (6-7 vs 5).

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