| Summary: | 博士 === 國立臺灣大學 === 海洋研究所 === 102 === Members of Coralliidae, known as precious corals, have been widely utilized as jewelry and other valuable artifacts. The species of Coralliidae are widely distributed in most oceans from tropical to subpolar seas ranging from 100 m to 2000 m, but only those in Mediterranean Sea and northwestern Pacific have been commercially harvested. Species of Coralliidae are vulnerable to fishing pressure due to their long life span, slow growth rates, and relatively late reproductive maturation. There is an urgent need to evaluate the status of precious corals and an accurate taxonomic system is essential for the assessment of population status and resource management. Thus, the aim of this study was to revise the taxonomy of Coralliidae based on morphological and phylogenetic relationships. A total of 110 specimens from major museums worldwide and several newly collected specimens were used in this study. Eight mitochondrial genes and one nuclear gene were applied as molecular markers to construct the phylogenetic relationship of coralliid corals, and three species of Paragorgiidae were chosen as the outgroup. The phylogenetic trees of Coralliidae showed that there were two monophyletic clades, and one of the clades included two subclades. Based on the results of genealogical analyses, Paracorallium was regarded as a junior synonym of Corallium, and the 3-genera classification of Coralliidae proposed by Gray (1867) was resurrected. Species in Clades IA, IB, and II have unique morphological features that correspond to those of Corallium Cuvier, 1798, Hemicorallium Gray, 1867, and Pleurocorallium Gray, 1867, respectively. The diagnostic features of each genus were redefined in this study. Based on the revised taxonomic system, there are 7, 18, and 18 species in Corallium, Hemicorallium, and Pleurocorallium, respectively. The morphological features of 9 species were re-described as references for species identification. The reexamination of type specimens also revealed that Pleurocorallium kishinouyei was a junior synonym of Pleurocorallium porcellanum. Furthermore, ten species are considered as new to science and described herein. A revised dichotomous key to 43 species of Coralliidae is provided. This study provides a revived taxonomic system of Coralliidae based on the coherence of phylogenetic relationships and morphological features. The system can be applied to the assessment of population status and conservation of Coralliidae.
|
|---|
