|Abstract: ||摘要 石花菜目為世界性分布廣泛的大型底棲性海洋紅藻，在台灣的藻種紀錄僅見於海藻相的研究文獻報告中，缺乏較完整的系統性調查。本研究以分子序列分析結果顯示，台灣產石花菜目石花菜科之藻種有十一個分類單元，分別位於五個屬內：阿房塔屬、隱果石花菜屬、石花菜屬、擬石花菜屬及翼枝菜屬。此結果與已紀錄的十八藻種相差甚大，可能有同種異名之誤判。阿房塔屬包含一個疑是新種，隱果石花菜屬包含一個疑是新種，石花菜屬包含三種（優美石花菜、日本石花菜及一個新紀錄種伊莎貝拉石花菜），擬石花菜屬包含兩種（匍匐擬石花菜及樊氏擬石花菜），而翼枝菜屬則包括四種（細翼枝菜、藍翼枝菜及兩個疑是新種）。本研究另一主要研究結果為發現過去紀錄為小石花菜的藻種，含有數種藻體外部形態類似的疑是新種。由形態觀察及分子序列分析結果顯示，台灣與香港（模式產地）的小石花菜藻種具有明顯遺傳差異。台灣產的小石花菜複合群含有四種不同的藻種，歸屬於3個不同屬中：隱果石花菜屬、石花菜屬及翼枝菜屬，包含兩個可能新種（隱果石花菜屬未確定種及翼枝菜屬未確定種），但仍須與世界其他各相近屬種進行進一步分析比對來確認。本研究亦發現兩個新紀錄種（伊莎貝拉石花菜及藍翼枝菜）。在台灣南北和蘭嶼均可採集到的 “細毛石花菜” 則分別為兩種疑是新種。另外，台灣過去紀錄的 “安曼司石花菜” 和 “太平洋石花菜” 則應是外觀形態多變的優美石花菜；而台灣北海岸過去紀錄的 “宻枝雞毛菜” 和 “雞毛菜” 均為細翼枝菜在不同季節或生長環境的不同生態型。|
Abstract The Order Gelidiales, consisting of a single family Gelidiaceae, comprises a dominant component of the marine flora in northern Taiwan. No taxonomic studies had been focusing on the Gelidiaceae from Taiwan, and the records of the Gelidiaceae were only seen in the previous marine floristic surveys of Taiwan. Therefore, a monograph of species diversity and systematic studies on Taiwan's Gelidiales based on morphological and molecular datasets is carried out herein. Molecular analyses showed that the newly collected species from around the coastlines of Taiwan felled into five clades (= five genera: Aphanta, Capreolia, Gelidium, Gelidiella and Pterocladiella) and eleven subclades (= eleven species). The number of the species of the Gelidiales found in this study is much fewer than the species recorded in the past and many synonyms and misapplied names might be the causes. Among the five clades/genera based on the molecular analyses and mophological investigations, Clade I Aphanta containing an undescribed species (Aphanta sp.), Clde II Capreolia containing an undescribed species (Capreolia sp.); Clade III Gelidium containing three species (Gelidium elegans, Gelidium japonicum and Gelidium isabelae); Clade IV Gelidiella containing two species (Gelidiella acerosa and Gelidiella fanii), and Clade V Pterocladiella containing four species (Pterocladiella capillacea, Pterocladiella caeurlescens, two undescribed species: Pterocladiella sp. 1 and Pterocladiella sp. 2). Our taxonomic studies on the genera Gelidium and Pterocladiella from Taiwan indicated that many records based on Japanese or European species were misidentification, i.e. G. "amansii", G. "crinale", G. "pusillium", P. "tenuis", P. "nana" etc. The results also showed that eleven species are actually belonging in Gelidiella, Gelidium and Pterocladiella among the eighteen previous records. In particular, the small species with decumbent thalli, recognized as "Gelidium divaricatum" or G. "crinale/pusillum" in the past, are actually containing several new records to Taiwan marine flora or "new" species in various genera of the family. Based on the rbcL sequence analysis, the so-called “Gelidium divaricatum” recorded from Taiwan is genetically different from Gelidium divaricatum from its type locality (Hong Kong Island) and contains four species within three genera (Gelidium isabelae, Pterocladiella caeurlescens, Capreolia sp. and Pterocladiella sp. 2). Among them, G. isabelae, P. caeurlescens are new records for Taiwan. Collections of “Gelidium crinale” from northern and southern and Orchid Island are different from G. crinale from its type locality (England) and are positioned in the genera Aphanta and Pterocladiella as undescribed species. Molecular analysis also indicated that the previous records of Gelidium “amansii” and Gelidium “pacificum” should be placed in Gelidium elegans, which morphologies are very variable in different seasons and habitats. Similarly, Pterocladiella “nana” and Pterocladiella “tenuis” recorded from northern Taiwan are ecotypes of Pterocladiella capillacea.