ABSTRACT

Twenty-one samples belonging to species of Spyridia Harvey with uncinate (= hook-shaped) spines on determinate lateral branches were investigated for their morphology with a focus on the structure of determinate branches, and for comparative chloroplast-encoded rbcL and nuclear LSU rDNA sequence analysis to elucidate their taxonomy and phylogeny. Currently, four Spyridia species with uncinate spines are recognized worldwide: S. alternans, S. cupressina, S. horridula and S. hypnoides. Of them, S. hypnoides has been recognized as the most common species with uncinate spines. In this study, we show that S. aculeata needs to be resurrected from S. hypnoides, and recognized as a distinct species based on samples from Israel, Red Sea, near the type locality. Spyridia aculeata is characterized by the spiral arrangement of determinate branches, incompletely corticated determinate branches, naked basal segment of determinate branches, by the presence of only acropetal cortication in the nodes of determinate branches, and by uncinate spines at the terminal node and on the first and second nodes of determinate branches. In our molecular analyses based on rbcL and LSU rDNA, although four Spyridia species with uncinate spines are supported on phylogenetic trees, they are not a monophyletic group. The feature of uncinate spines in Spyridia is recognized as a polyphyletic character. Our phylogenetic analysis using rbcL and LSU rDNA sequences reveals high gene sequence divergence (6.8–7.0% for rbcL and 1.2–1.3% for LSU rDNA) between samples of S. aculeata and S. hypnoides. Therefore, the distribution of S. hypnoides may be restricted to the Indian Ocean, whereas S. aculeata is widely distributed in the Atlantic Ocean including the Mediterranean Sea and the Red Sea. Another Spyridia species with uncinate spines, S. alternans, is recognized as a synonym of S. horridula by our detailed morphological observations of its type specimen.

摘要

研究了21个属于Spyridia Harvey物种的样品，这些样品在确定的侧枝上具有未融合的（钩形）刺，其形态学着眼于确定的分支结构，并比较了叶绿体编码的rbc L和核LSU rDNA序列分析以阐明其分类学和系统发育。目前，4个Spyridia物种钩突棘是全球公认的：S.交替，S. cupressina，S. horridula和S.羽藻。其中，猪链球菌被认为是棘突棘最常见的物种。在这项研究中，我们表明沙门氏菌需要从猪链球菌中复活，并根据以色列，红海附近类型附近的样本被识别为独特物种。头孢子虫的特征是确定分支的螺旋排列，确定分支的皮质不完全，确定分支的裸露的基底节段，在确定分支的节点中仅存在顶角皮质，以及在末端节和第一节的棘突棘和确定分支的第二个节点。在我们基于rbc L和LSU rDNA的分子分析中，尽管在系统发育树上支持4种带有棘突棘的Spyridia物种，但它们不是单系统群体。隐身棘突的特征被认为是多系性格。我们使用系统发生分析RBC L和LSU rDNA序列揭示了高基因序列差异（对于6.8-7.0％RBC的样品之间L和用于LSU rDNA的1.2-1.3％）S. aculeata和S.羽藻。因此，分布S.羽藻可被限制到印度洋，而S. aculeata广泛分布于大西洋，包括地中海和红海。通过我们对其类型标本的详细形态学观察，另一种具有棘突棘的Spyridia物种S. alternans被视为S. horridula的同义词。