紅珊瑚科系統分類與親緣關係之研究

Systematics and phylogeny of deep-sea precious corals (Anthozoa: Octocorallia: Coralliidae)

塗子萱(Tzu-Hsuan Tu)

指導教授 ： 戴昌鳳

共同指導教授 ： 鄭明修

國立臺灣大學/理學院/海洋研究所/博士(2014年)

https://doi.org/10.6342/NTU.2014.01847

摘要

紅珊瑚科物種的骨骼質地堅硬，具有亮麗光澤，長久以來被視為珠寶珊瑚，廣泛的加工成珠寶或各式藝品。紅珊瑚科物種從熱帶至亞極區海域，水深100至2000公尺皆有分布記錄，目前僅地中海及西北太平洋海域有商業規模採撈。紅珊瑚的生物特性包含壽命長，生長緩慢，以及生殖成熟晚等，使其易受漁業壓力影響，有關其資源評估與保育為全球矚目議題。然此資源評估必須依賴明確的物種描述與物種鑑定，本論文之目的為建立紅珊瑚科物種親緣關係，並以此重新檢視及建立紅珊瑚的分類系統，並描述新物種。
本研究廣泛蒐集世界各大博物館典藏的紅珊瑚科物種標本，加上新近採集的標本，共110件，以8個粒線體基因及1個核基因為分子標誌，並以3種擬柳珊瑚科物種作為外群，利用最大似然法及貝氏推論重建紅珊瑚科物種的親緣關係樹。結果顯示，所有紅珊瑚科物種為一單系群，可分為兩個主要系群（Clade I, Clade II），其中系群I又可分為兩亞群（Clade IA, Clade IB）。但是，現有的紅珊瑚屬（Corallium）及類紅珊瑚屬（Paracorallium）皆非單系群。檢視文獻得知，系群I的兩亞群及系群II物種的形質與Gray（1867）所描述的三屬分類系統符合。依據此分類架構，類紅珊瑚屬為紅珊瑚屬的同種異名，紅珊瑚屬則被分為紅珊瑚屬、半紅珊瑚屬(Hemicorallium)及側紅珊瑚屬(Pleurocorallium )等三屬。本研究依據親緣關係樹內各系群物種的形態特徵，以及Gray(1867)所提的各屬模式物種，重新定義三屬的形態特徵和各屬內的物種，包含紅珊瑚屬7物種、半紅珊瑚屬18種、側紅珊瑚屬18種。此外，重新檢視模式標本的結果亦顯示Pleurocorallium kishinouyei為P. porcellanum的同種義名；基於本研究所建立的親緣關係樹與已命名物種間的形態特徵比較，本研究一共命名了10種新種（半紅珊瑚屬3種，側紅珊瑚屬7種），重新描述九物種的形態特徵，並提供一完整的紅珊瑚科物種檢索表。依據本研究結果，紅珊瑚科包含有43個物種。本研究經由親緣關係及形態特徵的差異，重新界定各物種的界限，完成紅珊瑚科系統分類的檢討和修訂，可提供作為紅珊瑚科資源評估及保育的基礎資料。

關鍵字

紅珊瑚科 ； 紅珊瑚屬 ； 半紅珊瑚屬 ； 側紅珊瑚屬 ； 擬紅珊瑚屬 ； 親緣關係 ； 隱蔽種 ； 系統分類

並列摘要

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.

並列關鍵字

Coralliidae ； Corallium ； Hemicorallium ； Pleurocorallium ； Paracorallium ； phylogeny ； cryptic species, ； systematics

參考文獻

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