title: A new species of Ergasilus Nordmann, 1832 (Copepoda: Cyclopoida: Ergasilidae) from Bryconops giacopinii Fernández-Yépez (Characidae) in the Vichada River Basin, Colombia.
abstract: A new copepod species, Ergasilus curticrus n. sp. is described based on 14 female specimens collected from the gills of the characid teleost Bryconops giacopinii Fernández-Yépez, captured in the Vichada River Basin in Colombia. The new species has a unique combination of characters including: (i) 2-segmented endopods in legs 1 and 4; (ii) a semi-pinnate, falciform seta on the terminal segment of the first leg exopod; (iii) a 1-segmented fourth leg exopod; (iv) a reduced fifth leg with a single seta; and (v) a circular structure fused to a groove near the lateral margins of the second pedigerous tergite. Only two other known congeners have a 1-segmented leg 4 exopod, E. coatiarus Araujo & Varella, 1998 and E. iheringi Tidd, 1942. Among other characters, they differ from the new species by the lack of a semi-pinnate, falciform seta on the terminal exopodal segment of leg 1 and in the structure and armature of the fifth leg. The prevalence of E. curticrus n. sp. was 13.6% and its mean abundance was 0.4 specimens per host. This is the first new species of Ergasilus Nordmann, 1832 described from the Orinoco River Basin.
authors.affiliation: Grupo de Investigación en Ictiología Neotropical, Fundación para la Investigación y el Desarrollo Sostenible (FUNINDES), Avenida Roosevelt 24-80, 760042, Cali, Colombia.
authors.forename: Felipe
authors.initials: F
authors.lastname: Muriel-Hoyos
authors.affiliation: Departamento Central de Investigación, Universidad Laica Eloy Alfaro de Manabí, Ciudadela Universitaria Vía San Mateo, Manta, Manabí, Ecuador.|Fundación Colombiana para la Investigación y Desarrollo de Ecosistemas Acuáticos (FC. IDEA), Km. 18 vía al Mar, Cali, Colombia.
authors.forename: Ana María
authors.initials: AM
authors.lastname: Santana-Piñeros
authors.affiliation: Departamento Central de Investigación, Universidad Laica Eloy Alfaro de Manabí, Ciudadela Universitaria Vía San Mateo, Manta, Manabí, Ecuador. cqyanis@gmail.com.|Fundación Colombiana para la Investigación y Desarrollo de Ecosistemas Acuáticos (FC. IDEA), Km. 18 vía al Mar, Cali, Colombia. cqyanis@gmail.com.
authors.forename: Yanis
authors.initials: Y
authors.lastname: Cruz-Quintana
authors.affiliation: El Colegio de la Frontera Sur (ECOSUR) Unidad Chetumal, Av. Centenario Km. 5.5, 77014, Chetumal, Quintana Roo, Mexico.
authors.forename: Eduardo
authors.initials: E
authors.lastname: Suárez-Morales
mesh_terms: D000818:Animals; D060126:Characidae / Q000469:parasitology*; D003105:Colombia; D033342:Copepoda / Q000033:anatomy & histology* / Q000145:classification*; D005260:Female; D005880:Gills / Q000469:parasitology; D045483:Rivers; D013045:Species Specificity