title: Do genes lie? Mitochondrial capture masks the Red Sea collector urchin's true identity (Echinodermata: Echinoidea: Tripneustes).
abstract: Novel COI and bindin sequences of the Red Sea collector echinoid Tripneustes gratilla elatensis are used to show that (1) discordance between mitochondrial and nuclear loci exists in this echinoid genus, (2) Tripneustes gratilla as currently defined possibly comprises a complex of cryptic species, and (3) Red Sea Tripneustes form a genetically distinct clade in the bindin tree, which diverged from other Tripneustes clades at least 2-4million years ago. Morphological reassessment of T. gratilla elatensis shows perfect congruence between identification based on skeletal features and genetic data based on a nuclear marker sequence. Hence the Red Sea Tripneustes subspecies established by Dafni in 1983 is a distinct biological unit. All T. g. elatensis samples analyzed are highly similar to or share mtDNA haplotypes with Philippine T. g. gratilla, as do representatives from other edge-of-range occurrences. This lack of genetic structure in Indo-Pacific Tripneustes is interpreted as a result of wide-spread mitochondrial introgression. New fossil specimens from the Red Sea area confirm the sympatric occurrence of T. g. elatensis and T. g. gratilla in the northern Red Sea during Late Pleistocene, identifying a possible timing for the introgression. In addition, present-day distribution shows a contact zone in the Southern Red Sea (in the Dahlak Archipelago). T. g. elatensis, is yet another example of a Red Sea taxon historically identified as conspecific with its Indo-Pacific relatives, but which turned out to be a morphologically and genetically distinct endemic taxon, suggesting that the level of endemism in the Red Sea may still be underestimated.
authors.affiliation: Natural History Museum Vienna, Geological-Paleontological Department, Burgring 7, 1010 Vienna, Austria; Natural History Museum Vienna, Central Research Laboratories, Burgring 7, 1010 Vienna, Austria; The Steinhardt Museum of Natural History and National Research Centre, Tel Aviv University, Israel. Electronic address: omribronstein@gmail.com.
authors.forename: Omri
authors.initials: O
authors.lastname: Bronstein
authors.affiliation: Natural History Museum Vienna, Geological-Paleontological Department, Burgring 7, 1010 Vienna, Austria. Electronic address: andreas.kroh@nhm-wien.ac.at.
authors.forename: Andreas
authors.initials: A
authors.lastname: Kroh
authors.affiliation: Natural History Museum Vienna, Central Research Laboratories, Burgring 7, 1010 Vienna, Austria; University of Vienna, Department of Integrative Zoology, Vienna, Austria. Electronic address: elisabeth.haring@nhm-wien.ac.at.
authors.forename: Elisabeth
authors.initials: E
authors.lastname: Haring
mesh_terms: D000818:Animals; D045304:Cytochromes c / Q000145:classification / Q000235:genetics / Q000378:metabolism; D004247:DNA / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism; D004272:DNA, Mitochondrial / Q000145:classification / Q000235:genetics / Q000378:metabolism; D004447:Echinodermata / Q000033:anatomy & histology / Q000145:classification* / Q000235:genetics; D006239:Haplotypes; D019156:Indian Ocean; D010802:Phylogeny; D011956:Receptors, Cell Surface / Q000145:classification / Q000235:genetics / Q000378:metabolism; D016415:Sequence Alignment; D017422:Sequence Analysis, DNA
chemical_list: D004272:DNA, Mitochondrial; D011956:Receptors, Cell Surface; C035027:egg surface sperm receptor; D045304:Cytochromes c; D004247:DNA
keywords: Biogeography; Integrative taxonomy; Mitochondrial capture; Molecular phylogeny; Red Sea; Toxopneustidae