Evolutionary diversification of banded tube-dwelling anemones (Cnidaria; Ceriantharia; Isarachnanthus) in the Atlantic Ocean
Number of pages
Faculty of Science (FNWI)
Institute for Biodiversity and Ecosystem Dynamics (IBED)
The use of molecular data for species delimitation in Anthozoa is still a very delicate issue. This is probably due to the
low genetic variation found among the molecular markers (primarily mitochondrial) commonly used for Anthozoa. Ceriantharia
is an anthozoan group that has not been tested for genetic divergence at the species level. Recently, all three Atlantic species
described for the genus Isarachnanthus of Atlantic Ocean, were deemed synonyms based on morphological simmilarities of only
one species: Isarachnanthus maderensis. Here, we aimed to verify whether genetic relationships (using COI, 16S, ITS1 and ITS2
molecular markers) confirmed morphological affinities among members of Isarachnanthus from different regions across the Atlantic
Ocean. Results from four DNA markers were completely congruent and revealed that two different species exist in the Atlantic
Ocean. The low identification success and substantial overlap between intra and interspecific COI distances render the Anthozoa
unsuitable for DNA barcoding, which is not true for Ceriantharia. In addition, genetic divergence within and between Ceriantharia
species is more similar to that found in Medusozoa (Hydrozoa and Scyphozoa) than Anthozoa and Porifera that have divergence
rates similar to typical metazoans. The two genetic species could also be separated based on micromorphological characteristics
of their cnidomes. Using a specimen of Isarachnanthus bandanensis from Pacific Ocean as an outgroup, it was possible to estimate
the minimum date of divergence between the clades. The cladogenesis event that formed the species of the Atlantic Ocean is
estimated to have occured around 8.5 million years ago (Miocene) and several possible speciation scenarios are discussed.
If you believe that digital publication of certain material infringes any of your rights or (privacy) interests, please let
the Library know, stating your reasons. In case of a legitimate complaint, the Library will make the material inaccessible
and/or remove it from the website. Please Ask the Library, or send a letter to: Library of the University of Amsterdam, Secretariat, Singel 425, 1012 WP Amsterdam, The Netherlands.
You will be contacted as soon as possible.