Dissertation Research: A Cladistic Analysis of the Actiniarian Family Edwardsiidae and its Relationship to the Zoantharia

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9801370 Lipscomb The Zoantharia (which includes the Actiniaria sea anemones , Scleractinia stony corals , and Corallimorpharia coral-like polyps lacking a stony skeleton ) is characterized by the presence of an eight-rayed, bilaterally symmetric larval form, called the edwardsia larva. In most actiniarians, this larva is a transient stage that develops into an adult with twelve mesenteries and a distinctive basal disc. One family, the Edwardsiidae, gives its name to the larval stage because its adults retain eight mesenteries and lack a basal disc. The similarity between the larval form of other zoantharians and adult edwardsiids has given rise to various hypotheses including the hypothesis that the Edwardsiidae are the basal group or the derived crown group of the Zoantharia. The goals of this research are: (1) to evaluate hypotheses concerning the evolutionary placement of the Edwardsiidae in the Zoantharia using phylogenetic methods. Data for this will come from gross anatomical and histological investigation of adults, studies of developmental morphogenesis, scanning electron microscopy of nematocysts, and transmission electron microscopy of sperm. (2) Because the Edwardsiidae are apparently disappearing from many habitats, it is important for us to develop accurate species and generic characterizations and identification guides. Therefore we will initiate of a revision of the species and genera of Edwardsiidae that will include an analysis of morphological variation within species collected from the same area, lists of synonomy, distribution information, and indentification keys. The Dissertation Improvement Award will allow us to travel to collect specimens and to examine specimens in museum collections in Europe.