Dr. Martin Fikáček 團隊使用第三代定序 探索森林落葉層節肢動物多樣性
文．胡芳碩
在研究森林落葉節肢動物的多樣性時，能忽略幼生期嗎？使用第三代定序測試
基於多樣性高、數量多、體型小與分類學研究缺乏，探索森林中土壤與落葉的節肢動物相是一件非常具挑戰性的事，尤其是大部分生活在落葉裡面的節肢動物都沒辦法用形態學的方式來鑑定。也因為如此，盡管幼生期佔了標本比例的很大一部分，但在研究時常常會將他們忽略，然而這對於整體多樣性研究造成的影響程度仍然未知。
本研究以臺灣亞熱帶森林中的甲蟲為例，使用第三代定序技術來探索這個問題。我們的結果指出，盡管我們所採集到超過38%的標本是幼蟲，但多來自2-3個常見種，大部分種類的幼蟲很少被重複採集到，我們推測有可能是因為特殊的微環境需求或是幼蟲期時間很短所導致。
在我們所採用的多樣性分析中，忽略幼蟲對於隱翅蟲來說並沒有影響，但若以所有甲蟲來看，忽略幼蟲則會有顯著的影響，我們的研究表明在這類研究中，若成蟲與幼蟲都存在於同個微環境中，那幼蟲可能可以被忽略，倘若幼蟲與成蟲的生活環境或生物學特性截然不同，那忽略幼蟲就有可能造成分析上的偏差。
本文刊登於Insect Conservation and Diversity
by Martin Fikáček
In 2018, when I visited Taiwan for the first time and met Fang-Shuo Hu (胡芳碩), we started to discuss the idea of using DNA barcoding to identify all species in our leaf litter samples, to get some ideas about the diversity of leaf litter beetles in Taiwan. We also wanted to include larvae that were always ignored, and I wanted to show that ecological studies are biased a lot by that omission.
We got the first samples in 2019 in Huisun Reserve which Fang-Shuo selected, 4.5 years ago! The first sequences were still done in Prague by Sanger sequencing, but after I moved to Taiwan, we started to use Oxford Nanopore, with the massive support of Jen-Pan Huang and Le Hanh. For me, this paper is really important, as it is my first study addressing biodiversity in other than a taxonomic way, and the first paper in which we use next-gen sequencing.
You may ask what we discovered? In short, the leaf litter beetle diversity in Taiwan is really high, and we continue collecting and barcoding to get more data and a better idea. And, contrary to my guess, we have shown that ecologists may ignore larvae without getting the results biased in many cases: it is always nice to kill one´s idea with real data in hand. For more, read through the paper and wait for the second one that is more taxonomic and on the way!