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Diversity and systematics of sea anemones. Meg Daly Adorian Ardelean Ha Rim Cha. Acknowledgments. Michel Clareboudt, staff & faculty of Marine Sciences, SQU Daphne Fautin
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Diversity and systematics of sea anemones Meg Daly Adorian Ardelean Ha Rim Cha
Acknowledgments • Michel Clareboudt, staff & faculty of Marine Sciences, SQU • Daphne Fautin • American Association for the Advancement of Science, National Science Foundation, KU Natural History Museum & Biodiversity Research Center
Sea Anemones • Cnidaria • 2 layered, organ-less body, with stinging nematocysts • Anthozoa • Polyp form only • Actiniaria • Skeleton-less, solitary or clonal (not colonial)
Subclass Hexacorallia Antipatharia Actiniaria Ceriantharia Antipatharia Actiniaria Ceriantharia Zoanthidea Scleractinia Corallimorpharia Zoanthidea Scleractinia
Why study anemones? • Diverse in habitat, biology, life history • Understand evolution of colonies and skeletons among Anthozoa • Understand evolution of tissues, organs, and polarity in animals
Overview • Anemone diversity & systematics • Morphology & variability of Actinodendridae • Diversity & systematics of Corallimorpharia
Systematics & Diversity of Actiniaria Diversity Habitat Biology Life history Systematics Identification Morphology Molecules Role of Biodiversity Studies Evolution Biogeography
Anemone diversity--typical habits • Attached to rocks or coral skeletons • Intertidal to deep sea • In sand or mud • Intertidal to deep sea
Exotic habits • On living hermit crabs or gastropods • On jellyfish or comb jellies • On living sponges, corals & gorgonians
How does habit(at) manifest itself in morphology or biology? • Shape • Musculature • Reproductive biology • Symbionts
Shape • Burrowing forms tend to be long, slender, smooth • Intertidal forms are often “bumpy” with suckers that hold stones • Deep water forms tend to be thick, stout, with wide oral discs
Musculature • Burrowing forms have strong retractor and circular muscles, weak basilar muscles • Intertidal forms have strong marginal sphincters • Attached forms have weak circular and retractor muscles
Reproduction • Attached forms in shallow subtidal and in deep sea have free swimming larvae, deep sea forms may have very large larvae • Attached forms undergo longitudinal fission, burrowing forms undergo transverse fission
Symbionts • Photosymbionts in attached and burrowing forms in shallow water • Photosymbiotic forms have broad oral disc • Crab symbionts tend to have potent nematocysts
How can we interpret and understand this diversity? Taxonomy & systematics
What is it?Process ofidentification • Find specimen • Compare multiple specimens • Develop sense of range of variation in color, shape & morphology • Compare to descriptions of similar known species
Is it the same?Process of comparison • Color, habitus, biology & life history • Arrangement and morphology of mesenteries & muscles • Size, shape & distribution of nematocysts
Why does it matter? • Variation in biology and/or role in ecosystem • Repeatability and comparability of results
Biodiversity in Oman • Components of the tropical Indo-Pacific fauna • New species (possibly endemic) • Lacking representatives of Acontiaria
Omani Anemones A new species of Heteractis?
Anthopleura —biogeography and evolution in the intertidal zone • What role do history, geography, or habitat play in • loss or re-acquisition of asexual reproduction? • loss, change, or re-acquisition of photosymbionts?
Global Diversity of Edwardsiidae • Small burrowing anemones • Poorly known, difficult to collect
Morphology Variability Systematics of the sea anemone family Actinodendridae
General -morphology long, highly branched tentacles secondary branches primary branch column pedal disc 10 mm
Morphology -acrospheres + simple, pointed Actinostephanus haeckeli + bilobed, narrow Actinodendron arboreum species complex + bilobed, wide Actinodendron alcyonoideum + simple, capitate Megalactis sp.
acrosphere fired capsule Stinging capsules
General - habitat shallow water on sand on sea grass bed among rocks and corals on mud
General - distribution + tropical + Indian and Pacific Ocean and the Red Sea over 400 records
Variability + morphology of tentacles + color and color patterns + nematocysts (stinging capsules) Field research helps to understand variability
elongated tentacle contracted tentacle Variability - morphology Variant with long: tentacles, branches, acrospheres Actinodendron arboreum
Variability - morphology Variant with short: tentacles, branches, acrospheres Actinodendron arboreum
Variability with age + number of branches increases with age + acrospheres are longer in juvenile individuals Actinodendron arboreum adult juvenile
Variability with behavior tertiary branch secondary branch primary branch
normal secondary branches regenerated secondary branches Variability - regeneration of tentacles Actinodendron arboreum
Taxonomy - original descriptions versus reality Actinodendron alcyonoideum (Quoy and Gaimard, 1833) original description vs specimen from Fiji, near Dravuni Isl.
Vincent B. Hargreaves CORALLIMORPHARIA Adorian Ardelean George Miller Ha-Rim Cha The Natural History Museum and Biodiversity Research Center The University of Kansas Lawrence, KS, USA
Corallimorpharia • One of six orders of Zoantharia • Coral-like sea anemones • Solitary or colonial polyps without skeleton • Current Classification: four families, 13 genera, and 50 species • Widely distributed: from tropical to polar areas and from shallow to deep water • Questions in the classification and the phylogenetic relationships LeRoy (http://www.garf.org)
What do they look like? • Plate-like body Family Ricordeidae Watzl, 1922 Family Discosomatidae Duchassaing de Fombressin and Michelotti, 1864 (Photos by Vincent B. Hargreaves)
What do they look like? • Cylindrical body Family Sideractiidae Danielssen, 1890 Family Corallimorphidae Hertwig, 1882
Corallimorpharia from Red Sea Eilat Reef, Israel Discosoma unguja Discosoma nummiforme Rhodactis rhodostoma (photos by Baraka Kuguru)
Predictive Range Modeling Discosoma nummiforme SST_mean_monthly, SST_min_max_range, Salinity_ann_avg, Chlora, Tides