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Type: Article
Published: 2022-07-06
Page range: 120-134
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A new species of six-gilled hagfish (Myxinidae: Eptatretus) from the Lakshadweep Sea

Cochin University of Science and Technology, Kochi, Kerala 2Kerala State Council for Science, Technology and Environment, Thiruvananthapuram, Kerala 3ICAR—Central Marine Fisheries Research Institute, Kochi 682018.
ICAR—Central Marine Fisheries Research Institute, Kochi 682018.
ICAR—Central Marine Fisheries Research Institute, Kochi 682018.
ICAR—Central Marine Fisheries Research Institute, Kochi 682018. Mangalore University, Mangalagangotri, Mangalore, Karnataka, India-574199
ICAR—Central Marine Fisheries Research Institute, Kochi 682018.
ICAR—Central Marine Fisheries Research Institute, Kochi 682018.
ICAR—Central Marine Fisheries Research Institute, Kochi 682018.
Pisces Wadge Bank Western Indian Ocean Eptatretus wadgensis sp. nov. Myxiniformes taxonomy mitochondrial DNA


A new species of hagfish, Eptatretus wadgensis sp. nov., is described from the Wadge Bank, Lakshadweep Sea, India, obtained from a depth of ~250–300 m through deep-sea trawling. It is diagnosed by having six pairs of gill pouches and gill apertures, 3/3 multicusp teeth, total slime pores 67–69, six branchial slime pores, and ventral aorta bifurcating at the 4th or between 4th and 5th gill pouch. The new species has significant morphological differences in total dental cusps, total slime pores, body proportions and the absence of the nasal-sinus papilla when compared to congeners and formed a distinct clade in phylogenetic reconstruction and a genetic distance of 3.41–4.00% when comparing K2P parameters with the nearest species. A key to the Eptatretus species of the Indian Ocean is provided.



  1. Bardack, D. (1991) First fossil hagfish (Myxinoidea): A record from the Pennsylvanian of Illinois. Science, 254 (5032), 701–703.
    Barnard, K.H. (1923) Diagnoses of new species of marine fishes from South African waters. Annals of the South African Museum, 13 (8), 439–445.
    Bigelow, H.B. & Schroeder, W.C. (1952) A new species of the cyclostome genus Paramyxine from the Gulf of Mexico. Breviora, 8, 1–10.
    Böni, L., Fischer, P., Böcker, L., Kuster, S. & Rühs, P.A. (2016) Hagfish slime and mucin flow properties and their implications for defence. Scientific Reports, 6, 1–8.
    Dean, B. (1904) Notes on Japanese myxinoids: A new genus Paramyxine, and a new species Homeaokinoseana. Reference also to their eggs. The Journal of the College of Science, Imperial University of Tokyo, Japan, 19, 1–23.
    Fernholm, B. & Hubbs, C.L. (1981) Western Atlantic hagfishes of the genus Eptatretus (Myxinidae) with description of two new species. Fishery Bulletin, 79, 69–83.
    Fernholm, B. (1998) Hagfish systematics. In: Jorgensen J.M., Lomholt J.P., Weber R.E. & Malte H. (Eds.), The biology of hagfishes. Chapman & Hall, London, pp. 33–44.
    Fernholm, B., Norén, M., Kullander, S.O., Quattrini, A.M., Zintzen, V., Roberts, C.D., Mok, H.K. & Kuo, C.H. (2013) Hagfish phylogeny and taxonomy, with description of the new genus Rubicundus (Craniata, Myxinidae). Journal of Zoological Systematics and Evolutionary Research, 51 (4), 296–307.
    Fernholm, B., Kumar, B. & Norén, M. (2017) First record of hagfish (Cyclostomata: Myxinidae) in Indian waters. Journal of Threatened Taxa, 9 (6), 10365–10368.
    Fricke, R., Eschmeyer, W.N. & Fong, J.D. (2021) Species by family/subfamily. Available from: (accessed 28 January 2021)
    Girard, C.F. (1855) Contributions to the fauna of Chile. Report to Lieut. James M. Gilliss, U.S. N., upon the fishes collected by the U. S. Naval Astronomical Expedition to the southern hemisphere during the years 1849-50-51-52. S.n., Washington. [unknown pagination]
    Hensley, D.A. (1985) Eptatretus mendozai, a new species of hagfish (Myxinidae) from off the
    southwest coast of Puerto Rico. Copeia, 4, 865–869.
    Kase, M., Shimizu, T., Kamino, K., Umetsu, K., Sugiyama, H. & Kitano, T. (2017) Brown hagfish from the northwest and east coasts of Honshu, Japan are genetically different. Genes & Genetic Systems, 92, 197–203.
    Kumar, S., Stecher, G., Li, M., Knyaz, C. & Tamura, K. (2018) MEGA X: Molecular evolutionary genetics analysis across computing platforms. Molecular Biology and Evolution, 35, 1547–1549.
    Kuo, C.H., Huang, K.F. & Mok, H.K. (1994) Hagfishes of Taiwan (I): A taxonomic revision with description of four new Paramyxine species. Zoological Studies, 33, 126–139.
    Kuo, C.H. & Mok, H.K. (1994) Eptatretus chinensis: A new species of hagfish (Myxinidae;
    Myxiniformes) from the South China Sea. Zoological Studies, 33 (4), 246–250.
    McMillan, C.B. & Wisner, R.L. (1984) Three new species of seven-gilled hagfishes (Myxinidae, Eptatretus) from the Pacific Ocean. Proceedings of the California Academy of Sciences, 43 (16), 249–267.
    McMillan, C.B. (1999) Three new species of hagfish (Myxinidae, Eptatretus) from the Galápagos Islands. Fishery Bulletin, 97 (1), 110–117.
    McMillan, C.B. & Wisner, R.L. (2004) Review of the hagfishes (Myxinidae, Myxiniformes) of the northwestern Pacific Ocean, with descriptions of three new species, Eptatretus fernholmi, Paramyxine moki, and P. walkeri. Zoological Studies, 43 (1), 51–73.
    Mincarone, M.M. (2017) Redescription of the hagfishes (Myxinidae: Eptatretus) from southern Africa. Marine Biology Research, 13 (7), 797–810. 1287924
    Mincarone, M.M. & Fernholm, B. (2010) Review of the Australian hagfishes with description of two new species of Eptatretus (Myxinidae). Journal of Fish Biology, 77 (4), 779–801.
    Mincarone, M.M., Mwale, M., & Fernholm, B. (2011) First record and further description of the Cape hagfish Myxine capensis (Myxinidae) off Mozambique, western Indian Ocean. Journal of Fish Biology, 79, 806–811.
    Mincarone, M.M., Plachetzki, D., McCord, C.L., Winegard, T.M., Fernholm, B., Gonzalez, C.J. & Fudge, D.S. (2021) Review of the hagfishes (Myxinidae) from the Galapagos Islands, with descriptions of four new species and their phylogenetic relationships. Zoological Journal of the Linnean Society, 192 (2), 453–474.
    Mok, H.K. (2001) Nasal-sinus papillae of hagfishes and their taxonomic implications. Zoological Studies, 40, 355–364.
    Mok, H.K., Saavedra-Diaz, L.M. & Acero, P. (2001) Two new species of Eptatretus and Quadratus (Myxinidae, Myxiniformes) from the Caribbean coast of Colombia. Copeia, 2001 (4), 1026–1033.
    Mok, H.K. & McMillan, C.B. (2004) Bifurcating pattern of the ventral aorta and distribution of the branchial arteries of hagfishes (Myxiniformes), with notes on the taxonomic implications. Zoological Studies, 43 (4), 737–748.
    Møller, P.R. & Jones, W.J. (2007) Eptatretus strickrotti n. sp. (Myxinidae): First hagfish captured from a hydrothermal vent. Biological Bulletin, 212 (1), 55–66.
    Müller, J. (1836) Vergleichendeanatomie der myxinoiden, der cyclostomen mitdurchbohrtemgaumen. Erster Theil. Osteologie und Myologie. Abhandlungen der Königlichen Akademie der Wissenschaftenzu Berlin, for 1834, 65–340.
    Nelson, J.S., Grande, T.C. & Wilson, M.V. (2016) Fishes of the World. John Wiley & Sons, pp. 22–24
    Norman, J.R. (1937) Coast fishes. Part II. The Patagonian region (including the Straits of Magellan and the Falkland Islands). Discovery Reports, 16, 1–150.
    Palumbi, S., Martin, A., Romano, S., McMillan, W.O., Stice, L. & Grabowski, G. (1991) The Simple Fool’s Guide to PCR. University of Hawaii, Honolulu, 42 pp.
    Ronquist, F., Teslenko, M., Van der Mark, P., Ayres, D.L., Darling, A., Höhna, S., Larget, B., Liu, L., Suchard, M.A. & Huelsenbeck, J.P. (2012) MRBAYES 3.2: Efficient Bayesian phylogenetic inference and model selection across a large model space. Systematic Biology, 61 (3), 539–542.
    Sambrook, J., Fritsch, E.F. & Maniatis, T. (1989) Molecular cloning: A laboratory manual. 2nd Edition. Cold Spring Harbor Press, New York, New York, 545 pp.
    Shen, S.C. & Tao, H.J. (1975) Systematic studies on the hagfish (Eptatretidae) in the adjacent waters around Taiwan with description of two new species. Chinese Bioscience, 2, 65–80.
    Song, Y.S. & Kim, J.K. (2020a) Molecular phylogeny and classification of the family Myxinidae (Cyclostomata:Myxiniformes) using the supermatrix method. Journal of Asia-Pacific Biodiversity, 13 (4), 533–538.
    Song, Y.S. & Kim, J.K. (2020b) A new species of hagfish, Eptatretus wandoensis sp. nov. (Agnatha, Myxinidae), from the southwestern sea of Korea. ZooKeys, 926, 81–94.
    Song, Y.S. & Kim, J.K. (2020c) Range expansion and redescription of the hagfish Eptatretuswalkeri (Myxiniformes: Myxinidae) from Northeast Asia and its distinction from E. atami. Journal of Asia-Pacific Biodiversity, 13 (2), 182–188.
    Song, Y.S. & Kim, J.K. (2020d) A new species of hagfish, Eptatretus albiderma sp. nov. (Agnatha: Myxinidae), from Vietnam, with the keys to species of Eptatretus in East Asia. Marine Biodiversity, 50 (5), 1–9.
    Strahan, R. (1975) Eptatretus longipinnis, n. sp., a new hagfish (family Eptatretidae) from South Australia, with a key to the 5–7 gilled Eptatretidae. Austral. Zoologist, 18 (3), 137–148.
    Ward, R.D., Zemlak, T.S., Innes, B.H., Last, P.R. & Hebert, P.D. (2005) DNA barcoding Australia’s fish species. Philosophical Transactions of the Royal Society B: Biological Sciences, 360 (1462), 1847–1857.
    Wisner, R.L. & McMillan C.B. (1988) A new species of hagfish, genus Eptatretus (Cyclostomata, Myxinidae), from the Pacific Ocean near Valparaiso, Chile, with new data on E. bischoffi and E. polytrema. Transactions of the San Diego Society of Natural History, 21, 227–244.
    Wisner, R.L. & McMillan, C.B. (1995) Review of new world hagfishes of the genus Myxine (Agnatha, Myxinidae) with description of nine new species. Fishery Bulletin, 93, 530–550.
    Wisner, R.L. (1999) Descriptions of two new subfamilies and a new genus of hagfishes (Cyclostomata: Myxinidae). Zoological Studies, 38 (3), 307–313.
    Wongratana, T. (1983) Eptatretus indrambaryai, a new species of hagfish (Myxinidae) from the Andaman Sea. Natural History Bulletin of the Siam Society, 31 (2), 139–50.
    Zintzen, V., Roberts, C.D., Shepherd, L., Stewart, A.L., Struthers, C.D., Anderson, M.J., McVeagh, M., Noren, M. & Fernholm, B. (2015) Review and phylogeny of the New Zealand hagfishes (Myxiniformes: Myxinidae), with a description of three new species. Zoological Journal of the Linnean Society, 174 (2), 363–393.