Revision of the genus Georissus (Coleoptera, Hydrophiloidea, Georissidae) of Japan

  • Kohei Yasuda Entomological Laboratory, Faculty of Agriculture, Ehime University, Tarumi 3-5-7, Matsuyama, 790-8566 Japan
  • Hiroyuki Yoshitomi Entomological Laboratory, Faculty of Agriculture, Ehime University, Tarumi 3-5-7, Matsuyama, 790-8566 Japan
Keywords: minute mud-loving beetle, taxonomy, new species, new synonym, faunistics


Japanese species of the genus Georissus are revised. Seven species, including two new, G. (Neogeorissus) takahashii sp. nov. and G. (Ne.) satoi sp. nov. are recognized. Georissus (Neogeorissus) sakaii Satô, 1972 and G. (Ne.) katsuoi Nakane, 1995 are synonymized with G. (Ne.) japonicus Satô, 1972. Based on the type series and additional specimens, three subgenera and seven species are (re)described with SEM micrographs of the external morphology and figures of male and female genitalia. The terminology of some structures of the head and the pronotum are redefined for convenience of taxonomy. A key to the Japanese species is also given.


Akita K. 2008. Rediscovery of Georissus granulosus. Coleopterist’s News 164: 14–15 [in Japanese.]

Arai K. 2006. Newly recorded Coleoptera from Saitama Prefecture (10). Yosegaki 121: 1–10. [In Japanese.]

Archangelsky M., Beutel R.G. & Komarek A. 2016. 12.4. Georissidae Laporte, 1840. In: Beutel R.G. & Leschen R.A.B. (eds) Handbook of Zoology. Arthropoda: Insecta. Coleoptera, Beetles. Vol. 1: Morphology and Systematics (Archostemata, Adephaga, Myxophaga, Polyphaga partim) 2nd Ed.: 259–262. Walter de Gruyter, Berlin, New York.

Bameul F. 1989. Description du comportement de camouflage d’un Coléoptère: le déguisement actif de Georissus crenulatus (Coleoptera Georissidae), et proposition d’une nouvelle classification des déguisements chez les invertebrates. Comptes Rendus de l’Académie des Sciences (Paris), Série III 309: 351–356.

Beutel R.G. 1994. Phylogenetic analysis of Hydrophiloidea based on characters of the head of adults and larvae (Coleoptera: Staphyliniformia). Koleopterologische Rundschau 64: 103–131.

Beutel R.G. & Leschen R.A.B. 2005. Phylogenetic analysis of Staphyliniformia (Coleoptera) based on characters of larvae and adults. Systematic Entomology 30: 510–548.

Bocák L., Barton C., Crampton-Platt A., Chesters S.D., Ahrens D. & Vogler A.P. 2014. Building the Coleoptera tree-of-life for >8000 species: composition of public DNA data and fit with Linnaean classification. Systematic Entomology 39: 97–110.

Crowson R.A. 1950. The classification of the families of British Coleoptera. The Entomologist’s Monthly Magazine 86: 274–288.

Delève J. 1967a. Notes sur les Georissus d’Afrique et descriptions d’espèces nouvelles (Coleoptera: Georissidae). Bulletin de l’Institut royal des Sciences naturelles de Belgique 43 (26): 1–23.

Delève J. 1967b. The scientific results of the Hungarian Soil Zoological Expedition to the Brazzaville-Congo 18. Espèces de la famille Georyssidae (Coleoptera). Opuscula Zoologica 7 (2): 117–123.

Delève J. 1969. Quelques Georissus Latreille nouveaux de l’Indonésie, Vietnam et de Nouvelle Guinée (Coleoptera: Georissidae). Acta Zoologica Academiae Scientiarum Hungaricae 15 (1–2): 23–30.

van Emden F.I. 1956. The Georyssus [sic!] larva – a hydrophilid. Proceedings of the Royal Entomological Society of London (A) 31: 20–24.

Erichson W.F. 1847. Naturgeschichte der Insekten Deutschlands. Erste Abtheilung Coleoptera, Dritter Band. Vierte Lieferung. Nicholaische Buchhandlung, Berlin.

Fikáček M. 2012. A new species of leaf-litter inhabiting Georissus from Borneo (Coleoptera: Hydrophiloidea: Georissidae). Zootaxa 3316: 63–68.

Fikáček M. 2019. 17. Georissidae Castelnau, 1840. In: Ślipiński A. & Lawrence J.F. (eds) Australian Beetles Vol. 2 Archostemata, Myxophaga, Adephaga, Polyphaga (part): 251–257. CSIRO Publishing.

Fikáček M. & Falamarzi S. 2010. Georissus persicus sp. nov. from Iran, with notes on the West-Palaearctic species of the G. laesicollis group (Coleoptera: Georissidae). Acta Entomologica Musei Nationalis Pragae 50: 107–116.

Fikáček M., Delgado J.A. & Gentili E. 2012. The Hydrophiloid beetles of Socotra Island (Coleoptera: Georissidae, Hydrophilidae). Acta Entomologica Musei Nationalis Pragae 52: 107–130.

Fikáček M., Matsumoto K., Perkins P., Prokin A., Sazhnev A., Litovkin S. & Jäch M.A. 2021. The family Epimetopidae (Coleoptera: Hydrophiloidea): review of current knowledge, genus-level phylogeny, and taxonomic revision of Eupotemus. Acta Entomologica Musei Nationalis Pragae 61: 1–34.

Hansen M. 1999. World Catalogue of Insects 2: Hydrophiloidea (s. str.) (Coleoptera). Apollo Books, Amsterdam.

Hebauer F. 2004. Systematic and zoogeographical notes on the genus Georissus Latreille, 1809 (Coleoptera: Hydrophiloidea). Acta Coleopterologica 20 (1): 3–6.

ICZN 1998. Opinion 1891. Crenitis Bedel, 1881, Georissus Latreille, 1809 and Oosternum Sharp, 1882 (Insecta, Coleoptera): conserved. Bulletin of Zoological Nomenclature 55: 58–60. Available from [accessed 22 Mar. 2022].

Illiger J.C.W. 1807a. Nachlese zu den Bemerkungen, Berichtigungen und Zusätzen zu Fabricii Systema Eleutheratorum. Magazin für Insektenkunde 6: 296–317.

Illiger J.C.W. 1807b. Vorschlag zur Aufnahme im Fabricischen Systeme fehlender Käfergattungen. Magazin für Insektenkunde 6: 318–350.

Iwata T. & Iwata Y. 2012. Additional record of Georissidae from Saitama Prefecture. Sayabane, New Series 6: 18–19. [In Japanese.]

Kono H. 1936. H. Sauter’s Formosa-Ausbeute: Georyssidae [sic!]. (Coleoptera). Arbeiten über morphologische und taxonomische Entomologie aus Berlin-Dahlem, Berlin-Dahlem 3 (1): 53–54.

Kurosawa Y. 1950. Georyssidae [sic!]. Iconographia Insetorum Japonicorum. Hokuryukan, Tokyo.

Lafer G.S. 1989. Georissidae. In: Ler P.A. (ed.) Opredelitel‘ nasekomykh Dal‘nego Vostoka SSSR v shesti tomakh. Vol. 3. Zhestkokrylye, ili zhuki (part 1): 293–294. Nauka, Leningrad.

Latreille P.A. 1809. Genera Crustaceorum et Insectorum, secundum ordinem naturalem in Familias disposita, iconibus exemplisque plurimus explicate, Vol. 4. A. Koenig, Paris and Strassburg [Parisiis et Argentorati].

Lawrence J.F., Ślipiński A., Seago A.E., Thayer M.K., Newton A.F. & Marvaldi A.E. 2011. Phylogeny of the Coleoptera based on morphological characters of adults and larvae. Annales Zoologici (Warszawa) 61: 1–217.

Litovkin S.V. 2018. Contribution to the fauna and bionomy of Georissidae (Coleoptera) of Kyrgyzstan. Euroasian Entomological Journal 17 (6): 428–432.

McKenna D.D., Farrell B.D., Caterino M.S., Farnum C.W., Hawks D.C., Maddison D.R., Seago A.E., Short A.E.Z., Newton A.F. & Thayer M.K. 2015. Phylogeny and evolution of Staphyliniformia and Scarabaeiformia: forest litter as a stepping stone for diversification of nonphytophagous beetles. Systematic Entomology 40: 35–60.

Messner B. 1965. Zur Biologie der Georyssiden (Coleopt.). Entomologische Berichten 1964 (3): 97–100.

Messner B. 1972. Zur Biologie einheimischer Käferfamilien. 9. Georyssidae. Entomologische Berichten 1972: 1–4

Miwa Y. 1937. Remarks on some families of Coleoptera including some rare species from Japan. Konchû 11: 158–163. [In Japanese.]

Nakane T. 1963. Hydrophilidae. In: Nakane T., Ohbayashi K., Nomura S. & Kurosawa Y. (eds) Iconographia Insetorum Japonicorum Colore naturali edita Vol. 2 (Coleoptera). Hokuryukan, Tokyo. [In Japanese.]

Nakane T. 1966. New or little-known Coleoptera from Japan and its adjacent regions. XXIII. Fragmenta Coleopterologica, Tokyo 14: 55–58.

Nakane T. 1995. Notes on some little-known beetles (Coleoptera) in Japan. 13. Kita-Kyushû no Konchû 42: 41–46.

Ryndevich S.K., Prokin A.A., Makarov K.V. & Sundukov Y.N. 2021. The beetles of the families Helophoridae, Georissidae, Hydrophilidae, Hydraenidae, and Elmidae (Insecta: Coleoptera) of Kunashir Island and the Lesser Kurils. Journal of Asia-Pacific Biodiversity 14: 461–491.

Satô M. 1970. Une nouvelle espèce de genre Georyssus [sic!] Latreille au Japon (Coleoptera: Georyssidae [sic!]). Journal of Nagoya Women’s College 16: 199–200.

Satô M. 1972. The Georissid beetles of Japan. Journal of Nagoya Women’s College 18: 207–213.

Satô M. 1981. An outline of Japanese Georissidae. Coleopterist’s News 53: 1–4. [In Japanese]

Satô M. 1985. Georissidae. In: Ueno S., Kurosawa Y. & Satô M. (eds) The Coleoptera of Japan in Color Vol. II. Hoikusha, Osaka. [In Japanese]

Sharp D. 1888. Descriptions of some new Coleoptera from Japan. The Annals and Magazine of Natural History Series 6 2: 242–245.

Shepard W.D. 2003. The biology of Georissus californicus LeConte (Coleoptera, Hydrophilidae, Georissinae). Special Bulletin of the Japanese Society of Coleopterology 6: 121–128.

Shepard W.D. & Sites R.W. 2016. First record of a minute mud-loving beetle of the family Georissidae (Insecta: Coleoptera: Hydrophiloidea) in Thailand. The Natural History Bulletin of the Siam Society 61: 131–133.

Short A.E.Z. & Fikáček M. 2011. World catalogue of the Hydrophiloidea (Coleoptera): additions and corrections II (2006–2010). Acta Entomologica Musei Nationalis Pragae 51 (1): 83–122.

Short A.E.Z. & Fikáček M. 2013. Molecular phylogeny, evolution and classification of the Hydrophilidae (Coleoptera). Systematic Entomology 38: 723–752.

Short A.E.Z. & Hebauer F. 2006. World Catalogue of Hydrophiloidea – additions and corrections, 1 (1999–2005) (Coleoptera). Koleopterologische Rundschau 76: 315–359.

Stephens J.F. 1828–1829. Illustrations of British Entomology… Mandibulata, Vol. 2. Baldwin & Cradock, London.

Tabira Y. 2005. Coleoptera. Catalog of Wildlife in Shizuoka Prefecture. Shizuoka Prefecture. [In Japanese]

Tabira Y. & Ishikawa H. 2011. Record of Georissus babai at river side of Tenryugawa. Sayabane, New Series 3: 23–25. [In Japanese.]

How to Cite
Yasuda, K., & Yoshitomi, H. (2022). Revision of the genus Georissus (Coleoptera, Hydrophiloidea, Georissidae) of Japan. European Journal of Taxonomy, 817(1), 111–142.
Research article