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Published: 2020-08-18
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Unusual opecoelids from Red Sea triggerfishes with special reference to characteristic concepts of the Opistholebetinae Fukui, 1929 (Digenea: Opecoelidae)

Department of Zoology, Faculty of Sciences, New Valley University, Kharga, Egypt. Research Associate, Laboratory of Parasitology, Department of Ecology & Conservation Biology, College of Agriculture & Life Sciences, Texas A&M University, College Station, Texas 77843-2258, USA.
Corpus Christi Museum of Science & History, 1900 N. Chaparral St., Corpus Christi, Texas 78401, USA.
Department of Zoology, Faculty of Sciences, South Valley University, 83523 Qena, Egypt.
Department of Medical Parasitology, Faculty of Medicine, Assiut University, 71526 Assiut, Egypt.
Laboratory of Parasitology, Department of Ecology & Conservation Biology, College of Agriculture & Life Sciences, Texas A&M University, College Station, Texas 77843-2258, USA.
Balistidae Balistoides viridescens Birendralebes Egypt Gaevskajatrema Gaevskajatrema balistes n. sp. Gaevskajatrema perezi Gaevskajatrema ponticum key Macvicaria Macvicaria longicirrata Neopycnadena n. gen. Neopycnadena tendu n. comb. Neopycn


Three digeneans belonging to the Opecoelidae are reported and described from triggerfishes (Tetraodontiformes: Balistidae) collected in the northern Red Sea off Egypt. Both Macvicaria longicirrata (Manter, 1963) Aken-Ova, Cribb & Bray, 2008 and Neopycnadena tendu (Bray & Justine, 2007) n. comb. were recovered from the intestine of the titan triggerfish, Balistoides viridescens (Bloch & Schneider)—each represents a new host record—and Gaevskajatrema balistes n. sp. was found parasitizing the lower intestine of the Picasso triggerfish, Rhinecanthus assasi (Forsskål). We continue to support synonymy of Gaevskajatrema ponticum (Koval, 1966) Machkevsky, 1990 with Gaevskajatrema perezi (Mathias, 1926) Gibson & Bray, 1982, not as a differentiated species. We adopt the restricted posterior extension of the ceca and vitellarium to the testicular zone, without extension of either into the post-testicular space, as diagnostic in distinguishing Gaevskajatrema. Gaevskajatrema balistes n. sp. differs from G. perezi based on its substantially smaller body size with fewer eggs, a longer cirrus-pouch reaching ovarian level and it parasitizes a distinct host group from a structurally and ecologically different ecosystem. Neopycnadena n. gen. is erected for Pseudopycnadena tendu Bray & Justine 2007 based on its possessing a large broadly oval cirrus-pouch with a massive field of prostatic cells occupying the entire volume of the cirrus-pouch, a wide, cup-shaped and thick-walled ejaculatory duct, distinct dorsal position of the excretory pore, the bifurcal dextral position of the genital pore, its report from a distinct host group and distant locality and its phylogenetic uniqueness compared with Pseudopycnadena fischthali Saad-Fares & Maillard 1986. Neopycnadena n. gen. is ecologically similar to opistholebetines in their life-cycles and morphology; however, phylogenetically separate from opistholebetines as well as from the Polypipapiliotrematinae Martin, Cutmore & Cribb in Martin, Sasal, Cutmore, Ward, Aeby & Cribb, 2018 and members of Clade [C] of Martin and colleagues, thus we conclude that Neopycnadena n. gen. is unique. Neopycnadeninae n. subfam. is proposed to accommodate Neopycnadena n. gen. We consider that the probable characterization of tetraodontiform specialist taxa (as indicated by the presence of a muscular post-oral ring) and the specificity of the Opistholebetinae Fukui, 1929 sensu stricto with a tetraodontiform host are no longer reliable characters differentiating Gaevskajatrema and Macvicaria Gibson & Bray, 1982. The nature of the post-oral structure is discussed and it is adopted to be a diagnostic feature at the generic level among taxa of the Opistholebetinae sensu latu. It is concluded that the expanded concept of the Opistholebetinae is more supported than the restricted one, Birendralebes Srivastava & Ghosh, 1972 remains incertae sedis within the Opecoelidae Ozaki, 1925 rather than in the Opistholebetinae, and we provide a generic key to the Opistholebetinae.



  1. Aken’Ova, T., Cribb, T.H. & Bray, R.A. (2008) Eight new species of Macvicaria Gibson and Bray, 1982 (Digenea: Opecoelidae) from temperate marine fishes of Australia. ZooKeys, 1, 23–58.

    Andres, M.J., Pulis, E.E. & Overstreet, R.M. (2014) New genus of opecoelid trematode from Pristipomoides aquilonaris (Perciformes: Lutjanidae) and its phylogenetic affinity within the family Opecoelidae. Folia Parasitologica, 61 (3), 223–230.

    Antar, R., Georgieva, S., Gargouri, L. & Kostadinova, A. (2015) Molecular evidence for the existence of species complexes within Macvicaria Gibson & Bray, 1982 (Digenea: Opecoelidae) in the western Mediterranean, with descriptions of two new species. Systematic Parasitology, 91 (3), 211–229.

    Bartoli, P., Bray, R.A. & Gibson, D.I. (1989a) The Opecoelidae (Digenea) of sparid fishes of the western Mediterranean. III. Macvicaria Gibson & Bray, 1982. Systematic Parasitology, 13 (3), 167–192.

    Bartoli, P., Gibson, D.I. & Bray, R.A. (1988) The Opecoelidae (Digenea) of sparid fishes of the western Mediterranean. I. Pachycreadium Manter, 1954. Systematic Parasitology, 12 (3), 231–239.

    Bartoli, P., Gibson, D.I. & Bray, R.A. (2005) Digenean species diversity in teleost fish from a nature reserve off Corsica, France (Western Mediterranean), and a comparison with other Mediterranean regions. Journal of Natural History, 39 (1), 47–70.

    Bartoli, P., Gibson, D.I., Bray, R.A., Maillard, C. & Lambert, M. (1989b) The Opecoelidae (Digenea) of sparid fishes of the western Mediterranean. II. Pycnadenoides Yamaguti, 1938 and Pseudopycnadena Saad-Fares & Maillard, 1986. Systematic Parasitology, 13 (1), 35–51.

    Bilecenoglu, M., Yokes, M.B. & Eryigit, A. (2008) First record of Vanderhorstia mertensi Klausewitz, 1974 (Pisces, Gobiidae) in the Mediterranean Sea. Aquatic Invasions, 3 (4), 475–478.

    Boussellaa W., Neifar L., Goedknegt, M.A. & Thieltges, D.W. (2018) Lessepsian migration and parasitism: richness, prevalence and intensity of parasites in the invasive fish Sphyraena chrysotaenia compared to its native congener Sphyraena sphyraena in Tunisian coastal waters. PeerJ, 6, e5558.

    Bray, R.A. & Campbell, R.A. (1996) New plagioporines (Digenea: Opecoelidae) from deep-sea fishes of the North Atlantic Ocean. Systematic Parasitology, 33 (2), 101–113.

    Bray, R.A. (1985) Macvicaria taksengi n. sp. (Digenea: Opecoelidae) in marine teleosts from Pinang, Malaysia. Systematic Parasitology, 7 (1), 75–80.

    Bray, R.A. (1987) Some helminth parasites of marine fishes of South Africa: family Opecoelidae (Digenea). Journal of Natural History, 21 (4), 1049–1075.

    Bray, R.A. & Justine, J.L. (2007) Pseudopycnadena tendu sp. nov. (Digenea, Opecoelidae) in the yellow-spotted triggerfish Pseudobalistes fuscus (Perciformes, Balistidae) and additional opecoelids parasitizing fishes from the waters off New Caledonia. Acta Parasitologica, 52 (1), 13–17.

    Bray, R.A. & Justine, J.L. (2009) Opecoelids (Platyhelminthes, Digenea) from the fork-tailed threadfin bream Nemipterus furcosus (Valenciennes, 1830) (Perciformes, Nemipteridae), with preliminary keys to the problematic genera Macvicaria Gibson et Bray, 1982 and Neolebouria Gibson, 1976. Acta Parasitologica, 54 (3), 218–229.

    Bray, R.A., Waeschenbach, A., Cribb, T.H., Weedall, G.D., Dyal, P. & Littlewood, D.T.J. (2009a) The phylogeny of the Lepocreadioidea (Platyhelminthes, Digenea) inferred from nuclear and mitochondrial genes: Implications for their systematics and evolution. Acta Parasitologica, 54 (4), 310–329.

    Bray, R.A., Cribb, T.H. & Justine, J.L. (2009b) New observations on the genus Hypocreadium Ozaki, 1936 (Digenea: Lepocreadiidae) in the Indo-West Pacific region, including the description of one new species. Zootaxa, 2110 (1), 22–40.

    Bray, R.A., Cribb, T.H., Littlewood, D.T.J. & Waeschenbach, A. (2016) The molecular phylogeny of the digenean family Opecoelidae Ozaki, 1925 and the value of morphological characters, with the erection of a new subfamily. Folia Parasitologica, 63, 1–13.

    Bray, R.A., Waeschenbach, A., Dyal, P., Littlewood, D.T.J. & Morand, S. (2014) New digeneans (Opecoelidae) from hydrothermal vent fishes in the south eastern Pacific Ocean, including one new genus and five new species. Zootaxa, 3768 (1), 73–87.

    Burke, L., Kura, Y., Kassem, K., Revenga, C., Spalding, M., McAllister, D. & Caddy, J. (2001) Coastal Ecosystems. World Resources Institute, Washington, D.C., 77 pp.

    Bush, A.O., Lafferty, K.D., Lotz, J.M. & Shostak, A.W. (1997) Parasitology meets ecology on its own terms: Margolis et al. revisited. Journal of Parasitology, 83, 575–583.

    Caballero Rodríguez, G. (1970) Presencia de una metacercaria progenética en el hepatopáncreas del crustáceo Pseudothelphusa (Ptychophallus) tristani (Rathbun, 1896). Anales del Instituto de Biología. Universidad Nacional Autonóma de México, Serie Zoología, 41, 45–50.

    Cable, R.M. (1956) Opistholebes diodontis n. sp., its development in the final host, the affinities of some amphistomatous trematodes from marine fishes and the allocreadioid problem. Parasitology, 46 (1–2), 1–13.

    Cortini, M. & Ferretti, G. (1959) Pachycreadium carnosum (Rudolphi, 1819), n. comb, trematode parassita di Dentex vulgaris. Parassitologia, 1, 183–193.

    Cribb, T.H. (2005a) Family Opecoelidae Ozaki, 1925. In: Jones, A., Bray, R.A. & Gibson, D.I. (Eds.), Keys to the Trematoda. Vol. 2. CABI Publishing and The Natural History Museum, Wallingford, pp. 443–531.

    Cribb, T.H. (2005b) Family Opistholebetidae Fukui, 1929. In: Jones, A., Bray, R.A. & Gibson, D.I. (Eds.), Keys to the Trematoda. Vol. 2. CABI Publishing and The Natural History Museum, Wallingford, pp. 533–539.

    Cribb, T.H. & Bray, R.A. (2010) Gut wash, body soak, blender and heat-fixation: approaches to the effective collection, fixation and preservation of trematodes of fishes. Systematic Parasitology, 76 (1), 1–7.

    Cribb, T.H., Bray, R.A., Littlewood, D.T.J., Pichelin, S. & Herniou, E.A. (2001) The Digenea. In: Littlewood, D.T.J. & Bray, R.A. (Eds.), Interrelationships of the Platyhelminthes. Taylor & Francis, London, pp. 168–185.

    Dolgikh, A.V. & Naidenova, N.N. (1968) On the fauna of helminths of Gaidropsarus mediterraneus (L.) from the Black Sea. Parazitologiya, 2, 448–453.

    Dujardin, F. (1845) Histoire naturelle des helminthes ou vers intestinaux. Librairie Encyclopedique de Roret, Paris, xvi + 654 + 15 pp., 12 pls.

    Faltýková, A., Georgieva, S., Kostadinova, A. & Bray, R.A. (2017) Biodiversity and evolution of digeneans of fishes in the Southern Ocean. In: Klimpel S., Kuhn T. & Mehlhorn, H. (Eds.), Biodiversity and Evolution of Parasitic Life in the Southern Ocean. Parasitology Research Monographs. Springer International Publishing, Cham, pp. 49–74.

    Fayton, T.J. & Andres, M.J. (2016) New species of Plagioporus Stafford, 1904 (Digenea: Opecoelidae) from California, with an amendment of the genus and a phylogeny of freshwater plagioporines of the Holarctic. Systematic Parasitology, 93 (8), 731–748.

    Fischthal, J.H. & Thomas, J.D. (1968) Digenetic trematodes of some freshwater and marine fishes from Ghana. Proceedings of the Helminthological Society of Washington, 35 (2), 126–140.

    Fischthal, J.H. & Thomas, J.D. (1970) Digenetic trematodes of marine fishes from Ghana: family Opecoelidae. Proceedings of the Helminthological Society of Washington, 37 (2), 129–141.

    Froese, R. & Pauly, D. (Eds.) (2019) FishBase (version 08/2019). Available from: (accessed 17 July 2020)

    Gaevskaya, A.V. & Solonchenko, A.I. (1989) New data on the trematodes of Black Sea fish. Nauchnye Doklady Vyssheĭ Shkoly, Biologicheskie Nauki, Moscow, 5, 43–47.‏ [in Russian]

    Galil, B.S. & Zenetos, A. (2002) A sea change: exotics in the eastern Mediterranean Sea. In: Leppäkoski, E., Gollasch, S. & Olenin, S. (Eds.), Invasive Aquatic Species of Europe: Distribution, Impacts and Management. Springer, Dordrecht, pp. 325–336.

    Galil, B.S., Boero, F., Campbell, M.L., Carlton, J.T., Cook, E., Fraschetti, S., Gollasch, S., Hewitt, C.L., Jelmert, A., Macpherson, E., Marchini, A., McKenzie, C., Minchin, D., Occhipinti-Ambrogi, A., Ojaveer, H., Olenin, S., Piraino, S. & Ruiz, G.M. (2015) ‘Double trouble’: the expansion of the Suez Canal and marine bioinvasions in the Mediterranean Sea. Biological Invasions, 17 (4), 973–976.

    Garcia, L.S. & Ash, L.R. (1979) Diagnostic Parasitology: Clinical Laboratory Manual. 2nd Edition. The C.V. Mosby Company, London, 174 pp.

    Gibson, D.I. & Bray, R.A. (1982) A study and reorganization of Plagioporus Stafford, 1904 (Digenea: Opecoelidae) and related genera, with special reference to forms from European Atlantic waters. Journal of Natural History, 16 (4), 529–559.

    Hassanine, R.M.E.S. & Gibson, D.I. (2005) Trematodes from Red Sea fishes: Neohypocreadium aegyptense n. sp. (Lepocreadiidae), Fairfaxia cribbi n. sp. and Macvicaria chrysophrys (Nagaty & Abdel-Aal, 1969) (Opecoelidae). Systematic Parasitology, 62 (3), 199–207.

    Johnstone, J. (1907) Internal parasites and diseased conditions of fishes. Transactions of the Biological Society, Liverpool, 21, 270–303.

    Jousson, O., Bartoli, P. & Pawlowski, J. (1999) Molecular identification of developmental stages in Opecoelidae (Digenea). International Journal for Parasitology, 29 (11), 1853–1858.

    Justine, J.L., Briand, M.J. & Bray, R.A. (2012) A quick and simple method, usable in the field, for collecting parasites in suitable condition for both morphological and molecular studies. Parasitology Research, 111 (1), 341–351.‏

    Karar, Y.F., Blend, C.K., Khalifa, R.M., Hassan, H.A.S., Mohamadain, H.S. & Dronen, N.O. (2019) Re-examination of the phylogenetic relationships within the Gyliauchenidae Fukui, 1929 (Digenea) based on morphological and molecular evidence with a proposal for Paragyliaucheninae n. subfam. and a description of Flagellotrema convolutum Ozaki, 1936. Systematic Parasitology, 96 (7), 527–552.‏

    Kelly, D.W., Paterson, R.A., Townsend, C.R., Poulin, R. & Tompkins, D.M. (2009) Parasite spillback: a neglected concept in invasion ecology? Ecology, 90 (8), 2047–2056.‏

    Khalifa, R.M., Hassan, H.A.S., Mohamadain, H.S. & Karar, Y.F.M. (2015) Redescription of Pseudolepidapedon balistis Manter, 1940 and a biological variant (Trematoda: Acanthocolpidae) from the Red Sea fishes, Balistoides viridescens and Rhinecanthus assasi. Journal of the Egyptian Society of Parasitology, 240, 1–10.

    Korniychuk, J.M. (2000) Interspecific interactions of trematodes in the gut of Symphodus tinca. Ekologiya Morya, 52, 34–38.‏ [in Russian]

    Korniychuk, J.M. (2001) Structure of the trematode fauna of the Black Sea labrid fishes (Pisces: Labridae). Ekologiya Morya, 58, 32–36. [in Russian]

    Kovačić, M. & Golani, D. (2007) First record of Papillogobius melanobranchus in the Mediterranean Sea and new data on geographic distributions, bathymetric ranges and morphology of several small benthic fishes in the Levant. Cybium, 31 (4), 417–425.‏

    Koval, V.P. (1955) Critical review of the species composition of the genus Plagioporus (Trematoda, Digenea). Naukovi Zapsk Kyyivs’ski Derzhavni Universtet, 13 (16), 95–115. [in Russian]

    Koval, V.P. (1966) Digenetic trematodes of the genus Plagioporus Stafford 1904 from Ukrainian fishes. Visnyk Kyyivs Koho Universytetu, Seriya Biolohiyi, 8, 134–140. [in Ukrainian]

    Leiper, R.T. & Atkinson, E.L. (1914) Helminths of the British Antarctic Expedition 1910-1913. Proceedings of the Zoological Society of London, 1, 222–226.

    Lieske, E. & Myers, R.F. (1994) Collins Pocket Guide. Coral Reef Fishes: Caribbean, Indian Ocean, and Pacific Ocean including the Red Sea. Harper Collins, London, 400 pp.

    Lieske, E. & Myers, R.F. (1996) Coral Reef Fishes: Caribbean, Indian Ocean and Pacific Ocean including the Red Sea. Vol. 41. Princeton University Press, Princeton, 400 pp.

    Lieske, E., Fiedler, K.E. & Myers, R.F. (2004) Coral Reef Guide: Red Sea to Gulf of Aden, South Oman. The Definitive Guide to Over 1200 Species of Underwater Life. Collins, London, 384 pp‏.

    Linton, E. (1910) Helminth fauna of the Dry Tortugas. II. Trematode papers from the Tortugas. Laboratory of the Carnegie Institute of Washington, 4, 11–98.

    Linton, E. (1911) Trematodes of the Dry Tortugas. Science, 33 (843), 303–303.‏

    Looss, A. (1901) Über einige Distomen der Labriden des Triester Hafens. Centralblatt für Bakteriologie, Parasitenkunde und Infektionskrankheiten, 29, 398–405 + 437–442.

    Lymbery, A.J., Morine, M., Kanani, H.G., Beatty, S.J. & Morgan, D.L. (2014) Co-invaders: the effects of alien parasites on native hosts. International Journal for Parasitology, 3 (2), 171–177.‏

    Machida, M. (2011) Two new digenean trematodes (Lepocreadiidae and Monorchiidae) from balistid fishes of the West Pacific. Bulletin of the National Science Museum, Series A (Zoology), 34 (7), 171–175.

    Machida, M. (2014) Seven species of opecoelid digeneans (Trematoda) from fishes of southern Japan, Palau and the Philippines. Bulletin of the National Science Museum, Tokyo, Series A, Zoology, 40, 1–13.‏

    Machkevsky, V.K. (1990) Helminthofauna of labrids in the places of cultivation of Black-Sea mussel, Mytilus galloprovincialis. Ekologiya Morya, 36, 75–82.‏ [in Russian]

    Madl, P. (1999) Essay about the phenomenon of Lessepsian migration. Colloquial Meeting of Marine Biology I, Salzburg, April 1999 (revised in Nov. 2001). Available from: (accessed 28 February 2020)

    Maillard, C. & Raibaut, A. (1990) Human activities and modifications of ichthyofauna of the Mediterranean Sea: effects on parasitosis. In: Castri, F., Hansen, A.J. & Debussche, M. (Eds.), Biological Invasions in Europe and the Mediterranean Basin. Kluwer Academic Publishers, Dordrecht, Boston, London, pp. 297–305.

    Manter, H.W. (1940) Digenetic trematodes of fishes from the Galapagos Islands and the neighboring Pacific. Allan Hancock Pacific Expeditions, 2, 325–497.

    Manter, H.W. (1963) Studies on digenetic trematodes of fishes of Fiji. II. Families Lepocreadiidae, Opistholebetidae, and Opecoelidae. The Journal of Parasitology, 49 (1), 99–113.‏

    Margolis, L., Esch, G.W., Holmes, J.C., Kuris, A.M. & Schad, G. (1982) The use of ecological terms in parasitology (report of an ad hoc committee of the American Society of Parasitologists). The Journal of Parasitology, 68 (1), 131–133.‏

    Martin, S.B., Cutmore, S.C. & Cribb, T.H. (2017) Revision of Neolebouria Gibson, 1976 (Digenea: Opecoelidae), with Trilobovarium n. g. for species infecting tropical and subtropical shallow-water fishes. Systematic Parasitology, 94 (3), 307–338.‏

    Martin, S.B., Downie, A.J. & Cribb, T.H. (2020) A new subfamily for a clade of opecoelids (Trematoda: Digenea) exploiting marine fishes as second-intermediate hosts, with the first report of opecoelid metacercariae from an elasmobranch. Zoological Journal of the Linnean Society, 188 (2), 455–472.

    Martin, S.B., Huston, D.C., Cutmore, S.C. & Cribb, T.H. (2019) A new classification for deep-sea opecoelid trematodes based on the phylogenetic position of some unusual taxa from shallow-water, herbivorous fishes off south-west Australia. Zoological Journal of the Linnean Society, 186 (2), 385–413.‏

    Martin, S.B., Cutmore, S.C. & Cribb, T.H. (2018a) Revision of Podocotyloides Yamaguti, 1934 (Digenea: Opecoelidae), resurrection of Pedunculacetabulum Yamaguti, 1934 and the naming of a cryptic opecoelid species. Systematic Parasitology, 95 (1), 1–31.‏

    Martin, S.B., Crouch, K., Cutmore, S.C. & Cribb, T.H. (2018b) Expansion of the concept of the Opistholebetinae Fukui, 1929 (Digenea: Opecoelidae Ozaki, 1925), with Magnaosimum brooksae n. g., n. sp. from Tripodichthys angustifrons (Hollard) (Tetraodontiformes: Triacanthidae) in Moreton Bay, Australia. Systematic Parasitology, 95 (2–3), 121–132.‏

    Martin, S.B., Ribu, D., Cutmore, S.C. & Cribb, T.H. (2018c) Opistholobetines (Digenea: Opecoelidae) in Australian tetraodontiform fishes. Systematic Parasitology, 95 (8–9), 743–781.‏

    Martin, S.B., Sasal, P., Cutmore, S.C., Ward, S., Aeby, G.S. & Cribb, T.H. (2018d) Intermediate host switches drive diversification among the largest trematode family: evidence from the Polypipapiliotrematinae n. subf. (Opecoelidae), parasites transmitted to butterflyfishes via predation of coral polyps. International Journal for Parasitology, 48 (14), 1107–1126.‏

    Mathias, P. (1926). Sur une nouvelle espèce de Trématode, Peracreadium perezi; nov. sp. Bulletin de la Société Zoologique de France, 51, 353–356.

    Miller, P.J. (1990) Gobiidae. In: Quero, J.C., Hureau, J.C., Karrer, C., Post, A. & Saldanha L. (Eds.), Check-list of the Fishes of the Eastern Tropical Atlantic (CLOFETA). Vol. 2. JNICT, Lisbon, SEI and UNESCO, Paris, pp. 925–951.

    Nagaty, H.F. (1942) Trematodes of fishes from the Red Sea. Part 3. On seven new allocreadiid species. Publications of the Marine Biological Station Ghardaqa (Red Sea), 4, 1–27.

    Nagaty, H.F. & Abdel, A. (1969) Trematodes of fishes from the Red Sea. Part 18. On two new and one known allocreadiid species. Journal of the Egyptian Veterinary Medical Association, 29 (1/2), 1–5.‏

    Naidenova, N.N. (1974) Parasitic Fauna of the Fishes, Family Gobiidae, of the Black and Azov Seas. Publishing House (Naukova Dumkoa), Kiev, 182 pp. [in Russian]

    Nikolaeva, V.M. & Solonchenko, A.I. (1970) The helminth fauna of benthopelagic fish in the Black Sea. In: Delyamure, L.S. (Ed.), Parasites of Marine Molluscs, Fish and Mammals. Vol. 20. Biologiya Morya, Kiev, pp. 129–166. [in Russian]

    Oguz, M. & Bray, R.A. (2006) Digenetic trematodes of some teleost fish off the Mudanya Coast (Sea of Marmara, Turkey). Helminthologia, 43 (3), 161–167.‏

    Ozaki, Y. (1936) Short Reports. Flagellotrema convolutum, n. g., n. sp., a new trematode of the family Gyliauchenidae. Zoological Magazine, Japan, 48, 951–953.

    Prenter, J., MacNeil, C., Dick, J.T. & Dunn, A.M. (2004) Roles of parasites in animal invasions. Trends in Ecology & Evolution, 19 (7), 385–390.‏

    Price, E.W. (1934). New digenetic trematodes from marine fishes. Smithsonian Miscellaneous Collections, 91 (7), 1–8.

    Raitsos, D.E., Hoteit, I., Prihartato, P.K., Chronis, T., Triantafyllou, G. & Abualnaja, Y. (2011) Abrupt warming of the Red Sea. Geophysical Research Letters, 38, 1–5.

    Ramadan, M.M. (1985) On three species of the trematode genus Plagioporus Stafford, 1904 from Red Sea fishes. Qatar University Science Bulletin, 5, 267–278.

    Randall, J.E. (1982) The Diver’s Guide to Red Sea Reef Fishes. Immel Publishing and the University of California, Berkeley, 96 pp.

    Randall, J.E. (2013) Seven new species of labrid fishes (Coris, Iniistius, Macropharyngodon, Novaculops, and Pteragogus) from the western Indian Ocean. Journal of the Ocean Science Foundation, 7, 1–43.‏

    Reimer, L.W. (1987) Opecoelidae (Trematoda) von Meeresfischen vor Moçambique. Angewandte Parasitologie, 28 (3), 143–158.‏

    Rima, M., Marzoug, D., Pérez-del-Olmo, A., Kostadinova, A., Bouderbala, M. & Georgieva, S. (2017) New molecular and morphological data for opecoelid digeneans in two Mediterranean sparid fishes with descriptions of Macvicaria gibsoni n. sp. and M. crassigula (Linton, 1910) (sensu stricto). Systematic Parasitology, 94 (7), 739–763.‏

    Rothman, S.B. & Goren, M. (2015) First record of the Red Sea shrimp-goby Cryptocentrus caeruleopunctatus in the Mediterranean Sea. Marine Biodiversity Records, 8, 1–2.

    Rudolphi, K.A. (1819) Entozoorum synopsis cui accedunt mantissa duplex et indices locupletissimi. Rucker, Berolini, 811 pp.

    Saad-Fares, A. & Maillard, C. (1986) Trématodes des poissons des côtes du Liban-I: Pseudopycnadena fischthali n.g. n.sp. (Trematoda Opistholebetidae) parasite des Diplodus (Teleostei) des côtes du Liban. Annales de Parasitologie Humaine et Comparée, 61 (3), 303–309.‏

    Sarant, L. (2015) Suez Canal’s expansion widens corridor for marine invasion. Available from: (accessed 28 February 2020)

    Sasal, P., Niquil, N. & Bartoli, P. (1999) Community structure of digenean parasites of sparid and labrid fishes of the Mediterranean Sea: a new approach. Parasitology, 119 (6), 635–648.‏

    Shalaby, I.M.I. & Hassanine, R.M.E. (1997) Cryptacetabulum aegyptensis n. gen. n. sp. (Trematoda, Digenea: Opistholebetidae) from a Red Sea fish; as described by light and scanning electron microscopy. Journal of the Egyptian German Society of Zoology, 24, 247–259.

    Shimazu, T. & Nagasawa, K. (1985) Trematodes of marine fishes from Moroiso Bay, Misaki, Kanagawa Prefecture, Japan. Journal of Nagano-ken Junior College, 40, 7–15.

    Sokolov, S.G., Lebedeva, D.I., Shchenkov, S.V. & Gordeev, I.I. (2019) Caudotestis dobrovolski n. sp. (Trematoda, Xiphidiata) in North Pacific scorpaeniform fish: A crisis of concept of the opecoelid subfamily Stenakrinae Yamaguti, 1970. Journal of Zoological Systematics and Evolutionary Research, 1–12. [early view]

    ‏Sokolov, S.G., Shchenkov, S.V. & Gordeev, I.I. (2018) Records of opecoeline species Pseudopecoelus cf. vulgaris and Anomalotrema koiae Gibson & Bray, 1984 (Trematoda, Opecoelidae, Opecoelinae) from fish of the North Pacific, with notes on the phylogeny of the family Opecoelidae. Journal of Helminthology, 93(4), 475–485.‏

    Srivastava, C.B. & Ghosh, R.K. (1972) A new genus and new species of the trematode family Ophistholebetidae from India, with remarks on the systematic position of the families Ophistholebetidae and Gyliauchenidae. Journal of the Zoological Society of India, 24 (1), 53–60.

    Tkach, V.V., Pawlowski, J., Mariaux, J., Swiderski, Z., Littlewood, D.T.J. & Bray, R.A. (2001) Molecular phylogeny of the suborder Plagiorchiata and its position in the system of Digenea. In: Littlewood, D.T.J. & Bray, R.A. (Eds.), Interrelationships of the Platyhelminthes. Taylor & Francis, London, pp. 186–193.

    WoRMS (2020a) Macvicaria Gibson & Bray, 1982. World Register of Marine Species (WoRMS). Available from: (accessed 18 July 2020)

    WoRMS (2020b) Gaevskajatrema Gibson & Bray, 1982. World Register of Marine Species (WoRMS). Available from: (accessed 18 July 2020)

    WoRMS (2020c) Pseudopycnadena Saad-Fares & Maillard, 1986. Available from: (accessed 18 July 2020)

    WoRMS (2020d) Opistholebetinae Fukui, 1929. World Register of Marine Species (WoRMS). Available from: (accessed 18 July 2020)

    Yamaguti, S. (1938) Studies on the helminth fauna of Japan. Part 21. Trematodes of fishes, IV. Satyû Yamaguti, Kyoto, 139 pp.

    Yamaguti, S. (1952) Parasitic worms mainly from Celebes. Part 1. New digenetic trematodes of fishes. Acta Medicinae Okayama, 8 (2), 146–198.

    Yamaguti, S. (1971) Synopsis of Digenetic Trematodes of Vertebrates. Vols. I & II. Keigaku Publishing Company, Tokyo, 1423 pp.

    Zakaria, H.Y. (2015) Article review: Lessepsian migration of zooplankton through Suez Canal and its impact on ecological system. The Egyptian Journal of Aquatic Research, 41 (2), 129–144.‏

    Zdzitowiecki, K. (1987) Digenetic trematodes from the alimentary tract of fishes off South Shetlands (Antarctic). Acta Parasitologica Polonica, 32 (3), 219–232.