Skip to main content Skip to main navigation menu Skip to site footer
Published: 2023-03-14

Corymorpha tropica, a new species of anthoathecate hydrozoan (Cnidaria: Hydrozoa) from Southeast Asia

Hydrozoan Research Laboratory, 405 Chemin Les Gatiers, 83170 Tourves, France.
Hydrozoa Corymorphidae taxonomy hydroid medusa hydromedusa


A new species of corymorphid, Corymorpha tropica sp. nov., of common occurrence in Southeast Asia, is described. The account is based on both its hydroid and newly-released medusa. The caulus of the former is conspicuously divided into two distinct parts: a proximal, perisarc-covered, papillate, light brown to orange-colored portion, and a distal, naked, non-papillate, flesh to brick red-colored portion. The hydranth is equally variously-colored, and has either a distinctly-demarcated or a more diffuse red, circular band around its base. A whorl of long blastostyles, situated slightly above the aboral whorl of tentacles, give rise to isolated clusters of gonophores borne on short, lateral pedicels. The dispersive stage is a free-living medusa that is released without gonads from the parent hydroid. At this stage, its umbrella is bell-shaped, with a moderately developed, rounded, apical projection and scattered nematocysts on the exumbrella, and has three atentaculate, conical bulbs, as well as a main tentacle provided with a distal, large, globular nematocyst cluster and up to two intermediate knobs on its adaxial side, the position of the latter clusters being diagnostic.



  1. Agassiz, L. (1862) Contributions to the Natural History of the United States of America. Second monograph. Vol. 4. Little, Brown & Co., Boston, 380 pp.
    Alder, J. (1857) A catalogue of the zoophytes of Northumberland and Durham. Transactions of the Tyneside Naturalists’ Field Class, 3 (2), 93–162.
    Allman, G.J. (1872) A monograph of the gymnoblastic or tubularian hydroids. Conclusion of part I, and part II, containing descriptions of the genera and species of the Gymnoblastea. Ray Society, London, 295 pp.
    Allman G.J. (1876) Diagnoses of new genera and species of Hydroida. Journal of the Linnean Society of London, 12, 251–284.
    Boero, F., Bouillon, J. & Gravili, C. (2000) A survey of Zanclea, Halocoryne and Zanclella (Cnidaria, Hydrozoa, Anthomedusae, Zancleidae) with description of new species. Italian Journal of Zoology, 67, 93–124.
    Bouillon, J. (1978a) Hydroméduses de L’Archipel des Séchelles et du Mozambique. Revue de Zoologie Africaine, 92 (1), 117–173.
    Bouillon, J. (1978b) Hydroméduses de la Mer de Bismarck (Papouasie, Nouvelle Guinée). Partie I: Anthomedusae Capitata (Hydrozoa-Cnidaria) (1). Cahiers de Biologie Marine, 19, 249–297.
    Brinckmann-Voss, A. (1967) The hydroid of Vannuccia forbesii (Anthomedusae, Tubulariidae). Breviora, 263, 1–10.
    Brinckmann-Voss, A. (1970) Anthomedusae/Athecatae (Hydrozoa, Cnidaria) of the Mediterranean. Part I. Capitata. Fauna e Flora del Golfo di Napoli, 39, 1–96.
    Brooks, W.K. (1883) Notes on the medusae of Beaufort, N.C. Part II. Studies from the Biological Laboratory, Johns Hopkins University, 2, 465–475.
    Browne, E.T. (1916) Medusae from the Indian Ocean (Collected by Prof. Stanley Gardiner, in H.M.S. “Sealark” in 1905). Transactions of the Linnean Society of London, Series 2, 17, 169–209.
    Calder, D.R. (1972) Some athecate hydroids from the shelf waters of Northern Canada. Journal of Fisheries Research, Board of Canada, 29, 217–228.
    Clark, S.F. (1877) Report on the hydroids collected on the coast of Alaska and the Aleutian Islands, by W.H. Dall, U.S. Coast Survey, and Party, from 1871 to 1874 inclusive. Proceedings of the Academy of Natural Sciences of Philadelphia, 28, 209–238.
    Collins, A.G. (2000) Towards understanding the phylogenetic history of Hydrozoa: hypothesis testing with 18S gene sequence data. In: Mills, C.E., Boero, F., Migotto, A. & Gili, J.M. (Eds.), Trends in Hydrozoan Biology. Scientia Marina, 64 (S. 1), 5–22.
    Cornelius, P.F.S. (1992) Medusa loss in leptolid Hydrozoa (Cnidaria), hydroid rafting, and abbreviated life-cycles among their remote-island faunae: an interim review. Scientia Marina, 56 (2–3), 245–261.
    Da Silveira, F.L. & Migotto, A.E. (1992) Rediscovery of Corymorpha januarii Steenstrup, 1854 (Hydrozoa, Corymorphidae) on the southeastern and southern coasts of Brazil. Steenstrupia, 18 (4), 81–89.
    Du, F.Y., Xu, Z.Z., Huang, J.Q. & Guo, D.H. (2012) Studies on the medusae (Cnidaria) from the Beibu Gulf in the northern South China Sea, with description of three new species. Acta Zootaxonomica Sinica, 37 (3), 506–519.
    Du, F.Y., Lin, Z.J., Xu, Z.Z., Huang, J.Q. & Guo, D.H. (2013) Three new species of hydroidomedusae (Cnidaria) from the Meiji reef and Daya Bay, South China Sea. Acta Zootaxonomica Sinica, 38 (4), 749–755.
    Fraser, C.M. (1937) Hydroids of the Pacific coast of Canada and the United States. University of Toronto press, Toronto, 207 pp.
    Fraser, C.M. (1941) New species of hydroids, mostly from the Atlantic Ocean, in the United States National Museum. Proceedings of the United States National Museum, 91, 77–89.
    Fraser, C.M. (1944) Hydroids of the Atlantic coast of North America. University of Toronto Press, Toronto, 451 pp.
    Gershwin, L.A., Zeidler, W. & Davie, P.J.F. (2010) Medusae (Cnidaria) of Moreton Bay, Queensland, Australia. In: Davie, P.J.F. & Philips, J.A. (Eds.), Proceedings of the Thirteen International Marine Biological Workshop, The Marine Fauna and Flora of Moreton Bay, Queensland. Memoirs of the Queensland Museum, 54 (3), pp. 47–108.
    Hamond, R. (1974) Some medusae and other hydrozoa from the Indian Ocean and the Bass Strait. Journal of Natural History, 8, 549–561.
    Hargitt, C.W. (1924) Hydroids of the Philippine Islands. Philippine Journal of Science, 24 (4), 467–507.
    Hickson, S.J. & Gravely, F.H. (1907) Hydroid zoophytes. National Antarctic Expedition, 1901–1904, Natural History, 3, 1–34.
    Hirohito [Emperor of Showa] (1988) The hydroids of Sagami Bay. I. Athecata. Publications of the Biological Laboratory, Imperial Household, Tokyo, 179 pp. [English text]
    Huang, J.Q. (1999) Three new species of genus Euphysora from China seas (Hydrozoa: Anthomedusae, Corymorphidae). Acta Oceanologica Sinica, 18 (3), 435–441.
    Huang, J.Q., Xu, Z.Z., Lin, M., Guo, D.H., Wang, C.G. & Xue, W.L. (2012) One new genus, two new species and one new record of Corymorphidae from the South China Sea (Anthomedusae, Capitata). Acta Zootaxonomica Sinica, 37 (3), 520–524.
    Ikeda, I. (1910) On a new species of Corymorpha from Japan. Annotationes Zoologicae Japonenses, 7 (3), 153–164.
    Jäderholm, E. (1919) Zur Kenntnis der Hydroidenfauna Japans. Arkiv för Zoologi, 12 (9), 1–34.
    Kawamura, M. & Kubota, S. (2005) First occurence of Euphysora gemmifera (Cnidaria, Hydrozoa, Corymorphidae) in Japan. Biogeography, 7, 31–33.
    Kramp, P.L. (1928) Hydromedusae. I. Anthomedusae. In: Papers from Dr. Mortensesn’s Pacific Expeditions 1914–1916. Videnskabelige Meddelelser fra den Dansk Naturhistoriske Forening i Kjøbenhavn, 85, 27–64.
    Kramp, P.L. (1948) Trachymedusae and Narcomedusae from the “Michael Sars” North Atlantic Deep‑sea Expedition 1910, with additions on Anthomedusae, Leptomedusae, and Scyphomedusae. Report on the Scientific Results of the “Michael Sars” North Atlantic Deep-Sea Expedition 1910, 5 (9), 1–23.
    Kramp, P.L. (1957) Hydromedusae from the Discovery collections. “Discovery” Reports, 29, 1–128.
    Kramp, P.L. (1959) The hydromedusae of the Atlantic Ocean and adjacent waters. Dana Report, 46, 1–283.
    Kramp, P.L. (1961) Synopsis of the medusae of the world. Journal of the Marine Biological Association of the United Kingdom, 40, 1–469.
    Kramp, P.L. (1962) Medusae of Vietnam. Videnskabelige Meddelelser fra den Dansk Naturhistoriske Forening i Kjøbenhavn, 124, 305–366.
    Kramp, P.L. (1968) The hydromedusae of the Pacific and Indian Oceans. Sections II and III. Dana Report, 72, 1–200.
    Lin, M., Xu, Z.Z., Huang, J.Q., Nurul, F., Guo, D.H., Wang, C.G. & Chen B. (2013) Two new species of anthomedusae from the Bitung Strait, Indonesia (Cnidaria). Acta Zootaxonomica Sinica, 38 (2), 246–250.
    Liu, Z.Y., Yang, Y.Y., Xu, Z.Z. & Huang, J.Q. (2022) A new species of medusae from Luoyuan Bay, Fujian, China. Zoological Systematics, 47 (4), 345–348.
    Maas, O. (1905) Die craspedoten Medusen der Siboga-Expedition. Siboga-Expeditie, 10, 1–84.
    Maas, O. (1906) Méduses d’Amboine. Revue Suisse de Zoologie, 14 (1), 81–108.
    May, A.J. (1903) A contribution to the morphology and development of Corymorpha pendula Ag. American Naturalist, 37 (441), 579–599.
    Mayer, A.G. (1894) An account of some Medusae obtained in the Bahamas. In: Cruise of the steam Yacht “Wild Duck” in the Bahamas, January to April, 1893, in charge of Alexander Agassiz. Bulletin of the Museum of Comparative Zoölogy at Harvard College, 25, 235–242.
    Okada, Y.K. (1927) Études sur la régénération chez les cœlentérés. Archives de Zoologie Expérimentale et Générale, 66, 497–551.
    Owen, R. (1843) Lectures on comparative anatomy. Hunterian Lectures 1. Longman, Brown, Green, and Longmans, London, 392 pp.
    Petersen, K.W. (1990) Evolutional taxonomy in capitate hydroids and medusae. Zoological Journal of the Linnean Society, 100 (2), 101–231.
    Poppe, G.T. & Poppe, P (2022) Poppe Images, Marine iconography of the Philippine Archipelago. Available from: (accessed 14 December 2022)
    Rees, W.J. (1957) Evolutionary trends in the classification of capitate hydroids and medusae. Bulletin of the British Museum of Natural History, Zoology, 4 (9), 455–534.
    Sars, M. (1835) Beskrivelser og jagttagelser over nogle maerkelige eller nye i havet ved den Bergenske kyst levende dyr af polypernes, acalephernes, radiaternes, annelidernes og molluskernes classer, med en kort oversigt over de hidtil af forfatteren sammesteds fundne arter og deres forekommen. Thorstein Hallager, Bergen, 81 pp.
    Sars, M. (1860) Über das Ammengeschlecht Corymorpha und seine Arten nebst den von diesen aufgeammten Medusen. Archiv für Naturgeschichte, 26 (1), 341–351.
    Sassaman, C. & Rees, J.T. (1978) The life cycle of Corymorpha (=Euphysora) bigelowi (Maas, 1905) and its significance in the systematics of corymorphid hydromedusae. Biological Bulletin, 154, 485–496.
    Schuchert, P. (2010) The European athecate hydroids and their medusae (Hydrozoa, Cnidaria): Capitata Part 2. Revue Suisse de Zoologie, 117 (3), 337–555.
    Schuchert, P. & Collins, R. (2021) Hydromedusae observed during night dives in the Gulf Stream. Revue Suisse de Zoologie, 128 (2), 237–356.
    Stechow, E. (1932) Neue Hydroiden aus dem Mittelmeer und dem Pazifischen Ozean, nebst Bemerkungen über einige wenig bekannte Formen. Zoologischer Anzeiger, 100 (3–4), 81–92.
    Steenstrup, J.J.S. (1855) En ny og tropisk Art af Smaageplernes Ammeslaegt: Corymorpha Sars (Corym. Januarii Stp.). Videnskabelige Meddelelser fra den Dansk Naturhistoriske Forening i Kjøbenhavn, 1–3, 46–48.
    Svoboda, A. & Stepanjants, S.D. (2001) Redescription of two Antarctic Corymorphidae species and the reestablishment of the genus Monocaulus (Cnidaria: Hydrozoa). Marine Ecology, 22 (1–2), 53–70.
    Torrey, H.B. (1902) The Hydroida of the Pacific coast of North America. University of California Publications in Zoology, 1 (1), 1–104.
    Torrey, H.B. (1907) Biological studies in Corymorpha. II. The development of C. palma from the egg. University of California Publications in Zoology, 3 (12), 253–298.
    Uchida, T. (1927) Studies on Japanese hydromedusae. I. Anthomedusae. Journal of the Faculty of Science, Imperial University of Tokyo, Section IV, Zoology, 1, 145–241.
    Vanhöffen, E. (1911) Die Anthomedusen und Leptomedusen der Deutschen Tiefsee-Expedition 1898–1899. Deutsche Tiefsee-Expedition 1898–1899, 19 (5), 193–233.
    Vargas-Hernández, J.M. & Ochoa-Figueroa, E. (1990) Un nuevo genero y descripción de una nueva especie para la Familia Tubulariidae (Hidrozoa: Anthomedusae) en el Pacífico mexicano. Brenesia, 33, 75–80.
    Vervoort, W. (2009) Corymorpha tomoensis Ikeda, 1910 (Cnidaria, Hydrozoa); first record of a corymorphid hydropolyp from Indonesian waters and a review of the species of Corymorpha M. Sars, 1835. Zoologische Meddedelingen, Leiden, 83 (21), 759–776.
    Xu, Z.Z. & Huang, J.Q. (2003) On new species and records of Euphysora in Taiwan Strait and its adjacent waters (Cnidaria, Hydrozoa, Hydroidomedusae, Anthomedusae, Capitata, Corymorphidae). Journal of Oceanography in Taiwan Strait, 22 (2), 136–144.
    Xu, Z.Z. & Huang, J.Q. (2006) On new genus, species and record of Laingiomedusae and Anthomedusae in Fujian coast (Cnidaria, Hydroidomedusae). Journal of the Xiamen University (Natural Sciences), 45 (2), 233–249.
    Xu, Z.Z., Huang, J.Q., Lin, M., Guo, D.H. & Wang, C. G. (2014). The superclass Hydrozoa of the Phylum Cnidaria in China. Vol. 2. China Ocean Press, Beijing, pp. 495-945.
    Yamada, M., Konno, K. & Kubota, S. (1977) On a new athecate hydroid, Fukaurahydra anthoformis n.gen. n.sp., from northern Japan. Proceedings of the Japanese Academy of Sciences, 53 (3), 151–154.
    Vanhöffen, E. (1913) Die Craspedoten Medusen des “Vettor Pisani”. Zoologica, Stuttgart, 26 (67), 1–34.
    Watson, J.E. (1980) The identity of two tubularian hydroids from Australia with a description and observations on the reproduction of Ralpharia magnifica gen. et sp. nov. Memoirs of the National Museum of Victoria, 41, 53–63.
    Watson, J.E. (2008) Corymorpha rubicinta, a new hydroid (Hydrozoa, Athoathecata, Corymorphydae) from Port Phillip, Australia. Memoirs of the Museum of Victoria, 65, 185–188.