Acta Parasitologica

, Volume 53, Issue 1, pp 93–105 | Cite as

Intra- or inter-specific difference in genotypes of Caligus elongatus Nordmann 1832?

  • Øivind Øines
  • Thomas Schram
Original Paper


Two mitochondrial and one nuclear genetic marker were used to study the phylogenetic position of the two reported CO1-genotypes of Caligus elongatus in a group of closely related caligid parasites. Molecular analysis of the two mitochondrial genes (CO1 and 16S), indicate genetic distances of the two C. elongatus genotypes in the lower range of distances previously reported between other crustacean species, but higher than comparable reported within-species differences. Analyses of nuclear 18S sequences indicate no detectable differentiation between these genotypes, but may be due to expected differences in the resolution of these genetic markers. Investigation of two of three selected morphological characters reveals phenotypes supporting the division based on the molecular division. The species status on the two C. elongatus genotypes cannot be drawn conclusively, although the molecular and morphological data presented here suggests the presence of sibling species.


Parasitic copepod Caligus elongatus phylogeny 16S CO1 18S 


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Copyright information

© Versita 2008

Authors and Affiliations

  1. 1.Section for ParasitologyNational Veterinary InstituteOsloNorway
  2. 2.Department of BiologyUniversity of OsloBlindern, OsloNorway

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