Marine Biology

, Volume 133, Issue 1, pp 79–90

Mitochondrial and nuclear rRNA based copepod phylogeny with emphasis on the Euchaetidae (Calanoida)

  • E. Braga
  • R. Zardoya
  • A. Meyer
  • J. Yen
Article

DOI: 10.1007/s002270050445

Cite this article as:
Braga, E., Zardoya, R., Meyer, A. et al. Marine Biology (1999) 133: 79. doi:10.1007/s002270050445

Abstract

Phylogenetic relationships within the copepod family Euchaetidae and between representatives of three copepod orders (Calanoida, Harpacticoida, and Poecilostomatoida) were investigated using partial nucleotide sequences of the mitochondrial 16S rRNA and the nuclear 28S rRNA genes. DNA isolation, polymerase chain reaction, cloning, and DNA sequencing techniques were customized for these crustaceans. Our results support the monophyly of each copepod order, but in contrast to traditional morphology-based phylogenies of copepod orders, the Poecilostomatoida are basal to the Calanoida and Harpacticoida on our DNA-based phylogenetic tree. Phylogenetic trees generated by maximum parsimony, neighbor-joining, and maximum-likelihood analyses support the classification of the genera Euchaeta and Paraeuchaeta in the family Euchaetidae; results, however, suggest that Euchaetaacuta Giesbrecht is more closely related to species of the genus Paraeuchaeta than to those of Euchaeta, although limited taxon sampling may be partially responsible for this result. Phylogenetic mapping using the most parsimonious 16S tree suggests that the morphological synapomorphies distinguishing the genus Euchaeta evolved independently twice during the history of the Euchaetidae. Further, phylogenetic mapping suggests that the most recent common ancestor of the Euchaetidae and the Aetideidae was a deep-living, vertically migrating copepod, and that a bathypelagic, vertically migrating lifestyle characteristic of Paraeuchaeta is an ancestral trait of the family Euchaetidae which was lost apomorphically by Euchaeta. The application of a molecular clock suggests that the sibling species Euchaeta rimana Bradford and Euchaeta marina (Prestandrea) diverged due to the emergence of the Panamanian land bridge.

Copyright information

© Springer-Verlag Berlin Heidelberg 1999

Authors and Affiliations

  • E. Braga
    • 1
  • R. Zardoya
    • 2
  • A. Meyer
    • 3
  • J. Yen
    • 1
  1. 1.Marine Sciences Research Center, State University of New York at Stony Brook, Stony Brook, New York 11794-5000, USAUS
  2. 2.Museo Nacional de Ciencias Naturales, Jose Gutierrez Abascal, 2, E-28006 Madrid, SpainES
  3. 3.Department of Biology, University of Konstanz, D-78457 Konstanz, GermanyDE

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