Date of Degree
MS (Master of Science)
Ann F. Budd
Coral reefs are some of the most diverse ecosystems in the world and provide economic value as well as biodiversity stability. Yet, these ecosystems are threatened from human degradation and climate change. Phylogenetic reconstructions can help identify which species have a potential to undergo greater amounts of change in the near future and also aids in determining evolutionary distinctiveness, which are critical components of conservation management. However, traditional Scleractinia morphological characters have been shown to have limited taxonomic use. Therefore, this study attempts to discover soft tissue characters to produce more robust phylogenies. Eight coral species from the Indo-Pacific families Merulinidae and Lobophylliidae were mail ordered and prepared for histological analysis under light microscopy. A character matrix was analyzed and the results were compared to phylogenies based on skeletal and molecular data. A total of seven MPTs of length 35, C.I. 0.60 and R.I. 0.58 were found. In addition, a detailed description of the histology is included. The topology of MPTs was inconsistent, but several were broadly similar to previous phylogenies based on molecular and skeletal data. Still, using only a small number of characters, the results do promise that histological characters in conjunction with skeletal characters could better delineate species and their evolutionary history. Future results could aid in making conservation decisions based on improved phylogenies.
Human interactions with their environment can have profound negative effects and mitigation is often necessary. One area of concern is tropical coral reefs. Through anthropogenic climate change we are destabilizing coral reef ecosystems and reducing their functionality. Therefore, conservation strategies need to be implemented to reduce the negative impacts that affect these systems. Conservation methods have been developed which require well-supported evolutionary histories, but they are not currently applicable to reef-building corals. Past reconstructions of coral evolutionary history have not made use of the soft tissue due to difficulties preserving and preparing tissue. This study develops a methodology and provides a description of coral soft tissue with the goal of understanding more details about the evolutionary history of stony coral. Eight Indo-Pacific coral species were selected and prepared for analysis using equipment found in standard medical research facilities. Specifically, the morphology of stinging cells is discussed. The results show that evolutionary histories from this new source of data are broadly congruent with other studies. The addition of this new source of data to existing sources will yield results with greater utility. With these findings, conservation priorities can be developed based on evolutionary distinctiveness and coral reefs can maintain functionality in light of current environmental changes.
publicabstract, cnidocytes, histology, Lobophylliidae, Merulinidae, Scleractinia, systematics
Copyright 2015 David Russell Cordie