A new species of Ergasilus Nordmann, 1832 (Copepoda: Cyclopoida: Ergasilidae) from Bryconops giacopinii Fernández-Yépez (Characidae) in the Vichada River Basin, Colombia

Syst Parasitol. 2015 Nov;92(3):241-9. doi: 10.1007/s11230-015-9599-3. Epub 2015 Oct 7.


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.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Characidae / parasitology*
  • Colombia
  • Copepoda / anatomy & histology*
  • Copepoda / classification*
  • Female
  • Gills / parasitology
  • Rivers
  • Species Specificity