Contribución al conocimiento del estado actual de la ictiofauna de la cuenca baja de los ríos San Cipriano y Escalerete

El presente estudio contribuye al conocimiento de la ictiofauna de la cuenca baja de los ríos San Cipriano y Escalerete, tributarios del río Dagua. Los muestreos se realizaron entre Septiembre del 2003 y Agosto del 2004 en 13 estaciones donde se utilizaron como métodos de captura la electropesca, las nasas y los arrastres con redes. Como método complementario para obtener datos ecológicos de las especies y determinar la distribución espacial, se realizaron observaciones subacuáticas. Se registraron 36 especies distribuidas en 33 géneros, 23 familias y ocho órdenes, siendo los Siluriformes los de mayor representación específica (27.7%). De las especies reportadas 10 son especies eurihalinas, la mayoría de ellas de amplia distribución. En cuanto a la distribución, se determinó a partir de revisión bibliográfica, que del total de especies, 11 se encuentran reportadas para la vertiente pacífica de Colombia, 16 son de amplia distribución, 3 especies se reportan en el Pacífico ecuatoriano, mientras 6 especies se encuentran en otras cuencas vecinas como la del Cauca – Magdalena. Los resultados obtenidos permiten conocer la composición de especies de la cuenca de San Cipriano y Escalerete, y se aumentan los registros de especies para la cuenca del Dagua, de 45 a 55 especies. Se reconocieron como fuentes de presión para los peces de la zona, las actividades asociadas al tratamiento de agua potable, la introducción y trasplante de especies, la creciente actividad turística y el deterioro de la calidad de agua de algunos afluentesTrabajo de grado(Administrador del Medio Ambiente y de los Recursos Naturales)-- Universidad Autónoma de Occidente, 2006PregradoAdministrador(a) Ambienta

First record of Iotabrycon praecox Roberts 1973 (Characidae: Stevardiinae) in the Santa Rosa drainage, southwestern Ecuador

Iotabrycon praecox (Characidae: Stevardiinae) has been reported as endemic to the Guayas River drainage in Western Ecuador since its description in 1973. We collected one specimen of I. praecox in the Santa Rosa River, Santa Rosa drainage, El Oro Province, approximately 144 km south of the Guayas drainage, significantly expanding the known geographic distribution of the species. Given the severe anthropomorphic pressures impacting fishes in Southwestern Ecuador, there is an urgent need to evaluate the present status of I. praecox in the region

A new species of Chrysobrycon Weitzman & Menezes, 1998 (Characiformes, Characidae, Stevardiinae) with remarkable sexually dimorphic pigmentation from the upper Río Vaupés basin, Colombian Amazon, with taxonomic key

This study describes Chrysobrycon calamar, a new stevardiine fish from the upper Río Vaupés basin in Colombia. The new species differs from its congeners by the following combined characters: adult males have a dark vertical blotch on the abdominal flanks that is confined to a small area immediately dorsal to the urogenital region and anterior to the third anal-fin ray; adult males with a well-developed vertically humeral blotch, numerous tiny bony hooks on nearly all the upper lobe caudal-fin rays (except C. guahibo, C. hesperus, and C. mojicai), and bony hooks on nearly all branched anal-fin rays (except C. hesperus); the number of vertebrae (43 vs. 38–42); an elongated maxillary anterior process, representing 40% or more of the total length of the bone (vs. with a shorter maxillary anterior process, representing less than 40% of that length); and the posterior portion of the maxilla not reaching the vertical through the anterior border of the eye when the mouth is closed (except from C. yoliae). Additionally, C. calamar differs from C. mojicai by the number of maxillary teeth (2–4 vs. 9–17) and shape of the distal tips of most maxillary teeth (straight along their lengths vs. lateroventrally curved). Remarks on the interspecific color variation associated with sexual dimorphism and other characteristics of the genus are provided. A key to the species of Chrysobrycon is presented. The discovery of C. calamar is a key advance in the understanding of fish biodiversity associated with endemism-rich regions that could be explored after the guerrilla demobilized in Colombia

Genetic and Morphometric Evidence for the Recognition of Several Recently Synonymized Species of Trans-Andean \u3ci\u3eRhamdia\u3c/i\u3e (Pisces: Siluriformes: Heptapteridae)

A recent taxonomic revision of the Neotropical catfish genus Rhamdia (Pisces: Siluriformes: Heptapteridae) reduced a number of described species to synonymy, especially under a broadly circumscribed R. quelen. Evidence is presented here from DNA sequence data, external morphology, and morphometrics that argues for the recognition of R. guatemalensis in Central and northern South America and R. saijaensis and R. cinerascens in the Pacific drainages of Colombia and Ecuador, respectively. The DNA data indicate that all trans-Andean samples form a monophyletic group, within which there are separate clades corresponding to R. laticauda and the synonymized R. guatemalensis, R. saijaensis, and R. cinerascens. The morphometric data substantiate the phylogenetic groupings, and in external morphology, each putative species has diagnostic characters. Rhamdia guatemalensis is characterized by insertion of the adipose fin closer to the dorsal fin than to the caudal fin and presence of a conspicuous lateral longitudinal dark band; R. saijaensis is characterized by a small head with head length 20.8–23.4% of standard length and by lacking a lateral longitudinal band; and R. cinerascens is characterized by a large head with head length 25.8–30.1% of standard length, base of the adipose fin 30.3–33.3% of standard length, outer mental barbels extending to the base of the pectoral rays, and presence of a faint lateral longitudinal band. The external morphological differences and phylogenetic relationships indicate that these groups are both recognizable and represent independent lineages, which argue for their recognition as species

Range expansion of the genus Sicydium (Teleostei: Gobiidae) to coastal mountain streams of southwestern Ecuador and possibly northwestern Peru

We report collections of several specimens of Sicydium in 2013 and 2014 from the Jubones and Santa Rosa Rivers in southwestern Ecuador. These collections substantially expand the known range of the genus southward. The specimens are tentatively identified as Sicydium cf. rosenbergii based on their morphology. Small differences in morphology among specimens from the two rivers are noted, as are discrepancies with the type description. A museum database search uncovered two additional records of the genus south of their previously recognized range including one record from northwestern Peru

Catálogo de los recursos pesqueros continentales de Colombia

El documento que presentamos al público tiene una importancia tanto para la academia y centros de investigación como para las autoridades, tomadores de decisiones y el público en general, en aras de la generación de una conciencia colectiva sobre la problemática asociada a los recursos pesqueros y la necesidad de tomar medidas urgentes para su aprovechamiento sostenible por el bien común. En este contexto, el “Catalogo de los recursos pesqueros continentales de Colombia” contiene la información científicamente válida que ha llevado a establecer que las especies de peces de consumo y en consecuencia con alto valor comercial en aguas continentales son 173, cifra que probablemente se ampliará con futuros estudios y nuevos datos. De las especies listadas, 31 se encuentran categorizadas con algún grado de amenaza, siendo precisamente la causa el aprovechamiento derivado de su valor comercial, y que de continuar el aprovechamiento descontrolado, a la brevedad estaremos presenciando su extinción.Bogotá, D. C