Research Overview

The Indochina region possesses exceptional species diversity, high endemism, and a unique mix of Palearctic and Oriental fauna, especially in its northern mountain regions. Our research focuses on the terrestrial arthropods across East and Southeast Asia, where we conduct field visits and laboratory-based phylogenetic analyses to document local fauna, refine taxonomic classifications, investigate spatial distributions, and clarify evolutionary histories. We integrate morphological studies with phylogenetic analyses using Sanger and next-generation sequencing. Through our collaborations with researchers across Vietnam, Laos, Thailand, Malaysia, Indonesia, Brunei, Taiwan, China, and beyond, we have been able to cover a wide range of invertebrate taxa that include ants, wasps, hemipterans, termites, centipedes, millipedes, symphylans, spiders, pill isopods, and blood sucking leeches. We are also involved in studying the distribution, habitat, and life history of invasive ants (Formicidae) on island ecosystems that include the Ogasawara and Izu Islands for species management and control efforts. 

We also work with tardigrades, animals whose resilience has let them colonize nearly every corner of the planet. Our work centers on how these organisms reproduce and diversify. We compare sperm and egg structures between populations, characterize reproductive behaviors, probe the genetic basis of sex determination, and track how these traits map into species boundaries and evolutionary relationships. 

We welcome graduate students and postdocs from Asia who are interested in doing taxonomy and phylogeography to join our group. If you are interested in joining the graduate program and doing research with us, please contact us through email.  

Department Laboratory Page

Systematic Zoology Laboratory

Current Projects

(1) Taxonomy, Systematics and Phylogeography of Terrestrial Invertebrates

Much of the terrestrial invertebrate fauna in Southeast Asia remains undescribed or poorly classified, even as habitat loss threatens many species faster than we can document them. This project combines extensive fieldwork across the region (Vietnam, Thailand, Malaysia, Indonesia, Brunei, Taiwan, China) with laboratory analysis to examine different invertebrates (ants, wasps, termites, centipedes, millipedes, spiders, isopods, and leeches and describe species morphology and molecular phylogenetics in both live-caught samples and decades-old dried museum specimens.

(2) Diversity and Reproductive Biology of Tardigrades

Tardigrades occupy almost every known environment on earth, ranging from the big cities to the Arctic and Antarctic regions. This project focuses on understanding the diversity and reproductive biology of tardigrades by exploring and describing new tardigrade species across habitats, examining sexual morphological and behavioral features, and molecular studies on tardigrade chromosomes and sex determination mechanisms. We employ a combination of field sampling, phenotypic profiling, molecular biology, and genomics to elucidate differences in traits, genetic diversity, evolutionary history, and species distribution.

Staff Highlight

Dr. Katsuyuki Eguchi (江口 克之) Associate Professor	Dr. Kenta Sugiura (杉浦　健太) Assistant Professor
Email:
antist[at]tmu.ac.jp	kensugiura[at]tmu.ac.jp
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Lab Information: (Systematic Zoology Laboratory) Department Laboratory Page (Japanese)

Recent Publications

1. Sexual dimorphism, allometric morphological changes, and wild diet of the endemic Antarctic tardigrade Milnesium rastrum 

Kenta Sugiura, Natsume Takahira & Tomotake Wada. Zoological Letters, (In Press). Aug 2026

2. Integrative taxonomy of the genus Nesticus in central Japan, with the description of a new species and redescriptions 

of N. echigonus and N. gondai (Araneae, Nesticidae) 

Toshimichi Nagai, Francesco Ballarin, Katsuyuki Eguchi. ZooKeys, 1285, 125-145. Jul 2026

3. New geographic and host records of Chtonobdella catenifera (Moore, 1938) (Hirudinea, Hirudiniformes, Haemadipsidae) 

parasitizing Heosemys spinosa (Gray, 1831) and Manouria emys Schlegel & Müller, 1840 (Testudines) from West Sumatra, Indonesia 

Ardika Dani Irawan, Hariyo T. Wibisono, Alitha Mas Juanes, Takafumi Nakano, Katsuyuki Eguchi. Zootaxa, 5831(3), 427–436. Jun 2026

4. New species and new records of cave-dwelling money spiders from Japan with remarks on the genera Anguliphantes, 

Arcuphantes, Nihonella, Micrargus, and Porrhomma (Araneae, Linyphiidae) 

Francesco Ballarin, Toshimichi Nagai, Takeshi Yamasaki, Katsuyuki Eguchi. Zootaxa, 5828 (3), 401–449. Jun 2026

5. Molecular and morphological evidence for considering Odorrana gigatympana (Orlov, Ananjeva & Ho, 2006) 

a junior synonym of Odorrana absita (Stuart & Chan-ard, 2005) (Anura: Ranidae) 

Tan Van Nguyen, Anna S Dubrovskaya, Tosaphol Saetung Keetapithchayakul, Son Xuan LE, Katsuyuki Eguchi, Nikolay A Poyarkov. Zootaxa, 5828(1), 59-80. Jun 2026

6. Germ granule components regulate endosomal switching during the oocyte-to-embryo transition in Caenorhabditis elegans 

Shun-ichi Suto, Koh-ichi Teraoka, Ichiro Kawasaki, Kenta Sugiura, Taeko Sasaki, Ikuko Maejima, Hidetaka Kosako, Miyuki Sato & Ken Sato. Communications Biology, 9, 952. May 2026

7. Transmembrane ROOM proteins ensure rooms for germ cells by maintaining intercellular bridges 

Kenta Sugiura, Ichiro Kawasaki, Hidetaka Kosako, Ken Sato. Proceedings of the National Academy of Sciences, 23(19), e2522264123. May 2026

8. Distribution, Habitat Diversity, and Phylogeny of Anochetus shohki Terayama, 1996 (Hymenoptera: Formicidae) 

from Taiwan and the Ryukyu Archipelago of Southern Japan 

Fu-Ya Chung, Yu-Chun Hsiao, Katsuyuki Eguchi & Chung-Chi Lin. Asian Myrmecology 19, 019006 (1-15). Apr 2026

9. Erranticosa gen. nov.: a New Genus of Wolf Spiders from East Asia with Notes on its Separation from Lycosa and Hogna 

(Araneae Lycosidae: Lycosinae) 

Francesco Ballarin, Yuri M Marusik, Ren-Chung Cheng, Katsuyuki Eguchi. Zoological Studies, 65, e12. Apr 2026

10. Integrative taxonomy of the genus Biasticus (Hemiptera: Heteroptera: Reduviidae) known from Vietnam 

and its surrounding areas  

Ha Ngoc Linh, Truong Xuan Lam, Tadashi Ishikawa, Weeyawat Jaitrong, Chi Feng Lee, Bounsanong Chouangthavy, Nguyen Dac Dai, Anh D. Nguyen, Katsuyuki Eguchi. Zoologischer Anzeiger, 321, 286-332. Mar 2026

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