Molecular clocks provide new insights into the evolutionary history of Galeichthyine sea catfishes

  • Betancur-R. R
  • Armbruster J
  • 4

    Readers

    Mendeley users who have this article in their library.
  • N/A

    Citations

    Citations of this article.

Abstract

Intercontinental distributions in the southern hemisphere can either be the result of Gondwanan vicariance or more recent transoceanic dispersal. Transoceanic dispersal has come into vogue for explaining many intercontinental distributions; however, it has been used mainly for organisms that can float or raft between the continents. Despite their name, the Sea Catfishes (Ariidae) have limited dispersal ability, and there are no examples of nearshore ariid genera with a transoceanic distribution except for Galeichthys where three species occur in southern Africa and one in the Peruvian coast. A previous study suggested that the group originated in Gondwana, and that the species arrived at their current range after the breakup of the supercontinent in the Early Cretaceous. To test this hypothesis, we infer molecular phylogenies (mitochondrial cytochrome b, ATP synthase 8/6, 12S, and 16S; nuclear rag2; total ∼4 kb) and estimate intercontinental divergence via molecular clocks (penalized-likelihood, Bayesian relaxed clock, and universal clock rates in fishes). Age ranges for cladogenesis of African and South American lineages are 15.4–2.5 my, far more recent than would be suggested by Gondwanan vicariance; thus, the distribution of galeichthyines must be explained by dispersal or more recent vicariant events. The nested position of the Peruvian species (Galeichthys peruvianus) within the African taxa is robust, suggesting that the direction of the dispersal was from Africa to South America. The progenitor of the Peruvian species likely arrived at its current distribution with the aid of ocean currents, and several scenarios are discussed.

Author-supplied keywords

  • Ariidae
  • Gondwana
  • relaxed-clock methods
  • transoceanic dispersal
  • vicariance

Get free article suggestions today

Mendeley saves you time finding and organizing research

Sign up here
Already have an account ?Sign in

Find this document

Authors

  • R Betancur-R.

  • J W Armbruster

Cite this document

Choose a citation style from the tabs below

Save time finding and organizing research with Mendeley

Sign up for free