臺灣異擬蠍屬（擬蠍目：擬暴擬蠍科）的物種界定與分化歷史

Abstract

節肢動物蛛型綱擬蠍目下有許多形態高度保守且播遷能力有限的類群，例如許多棲息於森林中落葉層的擬蠍，無法單憑形態特徵或是生命條碼界定物種，有賴整合分類學協助釐清其物種界線。擬暴擬蠍科異擬蠍屬為東亞常見的落葉層擬蠍，在臺灣分布於中高海拔的森林中。我發現異擬蠍在臺灣具有高度的遺傳結構，且同一地點的樣本在傳統常用的鑑定特徵上也出現變異，導致物種的形態鑑定非常困難。因此，我結合分子資料與形態特徵，釐清臺灣異擬蠍屬的物種界線。本研究以一個粒線體基因與兩個核基因序列重建東亞異擬蠍的多基因親緣關係樹，結果顯示臺灣的異擬蠍為單系群。在整合形態與分子證據後，我認為臺灣共有七個具有顯著形態與分子差異的異擬蠍物種。臺灣異擬蠍的分化可能受到中新世晚期氣候變冷與上新世期間中央山脈快速隆起的影響。整體而言，這些棲息於中海拔落葉層的擬蠍，具有「天空島」的分布模式與高度的特有性。氣候變遷與棲地流失可能對這些在臺灣島內侷限分布的特有種造成威脅，因此進一步確認異擬蠍各物種在臺灣的分布對於維護其遺傳與物種多樣性具有重要意義。變遷及中央山脈的造山運動有關。整體而言，本研究結果指出：分布於臺灣中海拔地區、棲息於枯葉層中的擬蠍可能呈現「空中島嶼型分布」（sky-island pattern），具有高度特有性與狹窄的分布範圍。

Integrative taxonomy facilitates the determination of species boundaries for morphologically conserved taxa with limited dispersal abilities, such as litter-dwelling pseudoscorpions. The genus Allochthonius (family Pseudotyrannochthiniidae) is common in leaf litter habitats of mid-altitude forests in Taiwan but taxonomically challenging because of morphological variability within and between populations. I aimed to integrate molecular data and morphology to identify potential new species and diagnose them. A multi-locus phylogeny of 55 specimens from 11 locations using one mitochondrial and two nuclear genes revealed that Allochthonius in Taiwan is monophyletic, yet haplotypes are never shared among the sample localities. Molecular species delimitation based on three tree-based or distance-based methods identified seven, 13 and 15 molecular species respectively, with specimens from each location forming a monophyletic group. Consolidating these data with morphology, I recognize seven new species with replicable morphological and molecular differences: A. agyaqensis sp. nov., A. aquaeductensis sp. nov., A. brunus sp. nov., A. kiunnensis sp. nov., A. nebulosus sp. nov., A. nubicola sp. nov., A. tamanensis sp. nov. Morphologically, the number of glandular setae on male genitalia, the number of teeth on chela fingers, and setae numbers on the leg coxae are reliable characters for species identification. The diversification of Taiwanese species may be related to climatic changes during the late-Miocene and the orogeny of the Central Mountain Range. Overall, the data highlight that litter-dwelling pseudoscorpions living in the mid-altitudes of Taiwan might form a sky-island distribution pattern with high endemism and small distribution ranges.