PEET: Collaborative Research: Monographic Studies of the Hydractinioidea

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9978131Cunningham Coral reefs are among the most biologically diverse and ecologically intricate environments on earth, yet our knowledge of the organisms that constitute the reefs and inhabit their niches is fragmentary. For one major group of marine organisms often associated with reefs, the cnidarian class Hydrozoa, collaborating scientists Stephen Cairns at the Smithsonian Institution and Clifford Cunningham at Duke University are conducting monographic research while training new experts in hydrozoan taxonomy and compiling web accessible databases of information on these animals. The focal taxa are the families Campanularidae, Hydractiniidae and Stylasteridae (or hydrocorals), three morphologically distinct groups of Hydrozoa with worldwide distributions that appear to constitute phylogenetically sister taxa, on the basis of recent DNA sequence evidence. Although the freshwater Hydra is well-known since Leeuwenhoek's classic description, and is extensively used in modern cell biology research, it is atypical in lacking the medusa or swimming stage characteristic of most marine forms. These forms usually have an attached or polyp stage as well as a swimming or pelagic medusa stage as part of the life cycle; so different are the two stages in some groups that different nomenclatures have been created over the years, often for the same species. One of the goals of the research is to reconcile this dual taxonomy, in part by using mitochondrial DNA sequences as markers or signatures of species relatedness. With a sound phylogenetic classification in place, questions about biogeographic distribution, evolutionary origins, and tempo of diversification can be profitably pursued. The investigators are collaborating with colleagues in Canada (Dale Calder at the Royal Ontario Museum) and Italy (Ferdinando Boero at the University of Lecce) and others in studying museum specimens, culturing live organisms, adding new material from field expeditions, and training new experts in the taxonomy of these organisms. Students will participate fully in the field expeditions and museum visits as part of their overall training program in hydrozoan systematics. Morphological and molecular evidence will be integrated into the monographic studies, with new morphological characters from electron microscopy of nematocysts and other structures, and new molecular evidence from nuclear and mitochondrial ribosomal genes. In particular, Duke University is hosting a Hydrozoan Sequencing Facility, which will provide DNA sequence data from properly prepared collections, for purposes of identifying hydrozoans, placing them with evolutionary relatives, and tracking links between polyp and medusa stages in life cycle studies. Duke will also host the databasing component of the project, incorporating the new molecular data and providing links to Boero's electronic file of 12,000 taxonomic references and to other information resources.