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Phylogeny of the order Corallimorpharia (Cnidaria: Hexacorallia). Harim Cha Department of Ecology and Evolutionary Biology Natural History Museum & Biodiversity Research Center The University of Kansas harim@ku.edu. Corallimorpharia. One of six orders of Hexacorallia
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Phylogeny of the order Corallimorpharia(Cnidaria: Hexacorallia) Harim Cha Department of Ecology and Evolutionary Biology Natural History Museum & Biodiversity Research Center The University of Kansas harim@ku.edu
Corallimorpharia • One of six orders of Hexacorallia • Coral-like sea anemones • Solitary or clonal polyps without skeleton • Current Classification four families, 12 genera, and 50 species • Widely distributed from tropical to polar areas and from shallow to deep water Adorian Ardelean George Miller Vincent B. Hargreaves
Cylindrical body (CO I) Family Sideractiidae Family Corallimorphidae Plate-like body (CO II) Family Ricordeidae Family Discosomatidae Corallimorpharia • Questions about relationships within the order Vincent B. Hargreaves Vincent B. Hargreaves
Questions about relationship between Corallimorpharia and orders Actiniaria (sea anemones) and Scleractinia (stony corals) Corallimorpharia Hypothesis 1 Hypothesis 2 SC CO AC SC CO AC Hypothesis 3 Hypothesis 4 SC CO AC SC CO CO AC
Phylogenetic hypothesis based on molecular data a. Fautin & Lowenstein (1994): radioimmunoassay b. Chen et al. (1995): 28S rRNA c. France et al. (1996): 16S rRNA d. Daly et al. (2003): Morphology, 16S, 18S, 28S e. Medina et al. (2006): mtDNA
Phylogenetic analysis using morphological characters • Major characters used for analysis: • Calcareous exoskeleton • Polyp shape / size • Tentacle shape / number / arrangement • Nature of mesenteries and mesenterial arrangement • Muscle development • Nematocyst composition • Life style – solitary or clonal • Habitat • Zooxanthellae • Methods: • 32 morphological characters • 12 genera of Corallimorpharia, 6 genera of Scleractinia, and 11 genera of Actiniaria • Outgroup: genus Cerianthus • Maximum parsimony criterion, 1000 bootstrap replicates
CO I Corallimorpharia (CO) CO II CO I Scleractinia (SC) Actiniaria (AC) Ceriantharia (CE) • Maximum Parsimony analysis • (CI = 0.58, RI = 0.69) • Strict consensus tree of 12 equally parsimonious trees • Number of parsimony informative characters = 30
Phylogenetic analysis using molecular characters • Genes sequenced:16S mtDNA (1233 bp), 28S rDNA (345 bp), 18S rDNA (1836 bp) • Taxon sampling:Corallimorpharia - more than one genus of each family except family Sideractidae - collected from Oman and Caribbean - borrowed from the Field MuseumScleractinia - Robust and Complex groups Actiniaria - at least one taxon of each tribe • Outgroup: Genus Cerianthus • MacClade 4.0 and PAUP 3.3.1 • Maximum likelihoodMaximum parsimony – 2000 bootstrap replicates
Results Maximum Likelihood 16S mtDNA Robust Scleractinia (RS) Maximum Parsimony analysis • Strict consensus of 9 equally parsimonious trees • Number of parsimony-informative characters: 498 Complex Scleractinia (CS) Ceriantharia (CE) Robust Scleractinia (RS) Corallimorpharia (CO) CO II Corallimorpharia (CO) CO I Complex Scleractinia (CS) Actiniaria (AC) Actiniaria (AC) Ceriantharia (CE)
CO II CO AC CO I CO II CO RS CO I Scleractinia CS CE AC CE 28S rDNA maximum likelihood analysis 18S rDNA maximum likelihood analysis
Summary of results • Phylogeny based on morphological characters1) Plate-like corallimorpharians are more closely related to deep-sea cylindrical corallimorpharians (genera Corallimorphus, Sideractis, Nectactis, and Sphincteractis) than to shallow-water ones.2) Corallimorpharia is a monophyletic group3)Corallimorpharia is a sister taxon of Scleractinia • Each gene gives a different signal on phylogenetic relationships of Corallimorpharia1) 16S mtDNA: Corallimorpharia is monophyletic and a sister taxon of the Complex group of Scleractinia 2) 28S rDNA: Corallimorpharia is monophyletic and a sister taxon of Scleractinia3) 18S rDNA: Corallimorpharia is within Scleractinia
Further study • Better molecular markers are required to resolve higher level phylogeny of Hexacorallia • Extensive morphological data including polyp anatomy of scleractinians may help to clarify the position of corallimorpharians • Data from deep-sea corallimorpharians (family Sideractidae) will complete sampling of corallimorpharians and may be able to provide new insights on corallimorpharian phylogeny
Acknowledgments • Dr. Daphne Fautin and all lab people • Dr. Adorian Ardelean (WHOI) • Dr. Paulyn Cartwright (KU) • Dr. Rachel Collin (STRI) • Dr. Meg Daly (OSU) • Mr. Matthew Kost (KU) • Ms. Abby Reft • Dr. Sandra Romano (UVI) • NSF grant 9978106 in the program Partnerships to Enhance Expertise in Taxonomy (PEET) to Dr. Daphne Fautin • KU Natural History Museum and Biodiversity Research Center • Department of Ecology and Evolutionary Biology, KU