Abstract
Modified and/or new keys to the four subfamilies now recognized within the Megaperidae Manter, 1934 n. comb. (Syn. Apocreadiidae Skrjabin, 1942) as well as the genera within each subfamily are presented. Two new genera, Paraschistorchis n. gen. and Plesioschistorchis n. gen., both within the Schistorchiinae Yamaguti, 1942, are erected and keys are provided to the species considered in both new genera—distinguished by possessing caeca that end either in separate ani or blindly. Plesioschistorchis callyodontis (Yamaguti, 1942) n. comb. and Plesioschistorchis haridis (Nagaty, 1957) n. comb. are re-described from new material collected from the common parrotfish, Scarus psittacus Forsskål (Perciformes: Scaridae), inhabiting the Red Sea off Egypt; S. psittacus represents a new host record for both species. The taxonomic status of Schistorchis sensu stricto Lühe, 1906 is examined and revised, a key to the four species we consider in this genus offered, and the monotypic genus Megacreadium Nagaty, 1956 declared a junior synonym of Schistorchis. Members of Schistorchis sensu stricto possess a unique “complex” (i.e. highly cellular/glandular) instead of “simple” (i.e. entirely muscular) type of oral sucker that is quite large in relation to body size; an elongate, somewhat sub-rectangular-shaped body; 5+ testes arranged in at least two rows; caeca that open via separate ani; a long post-testicular region; a median genital pore either at the anterior margin of or just anterior to the ventral sucker; and species of Schistorchis sensu stricto parasitize the intestine of marine fish within the Order Tetraodontiformes Berg. With the revision of this genus, we re-describe Schistorchis carneus Lühe, 1906 from the lower and mid-intestine of the white-spotted puffer, Arothron hispidus (Linnaeus) (Tetraodontiformes: Tetraodontidae), collected in the Red Sea off Egypt. Finally, a plea is made for further study of the Megaperidae n. comb. focusing, in particular, on the following: (1) obtaining new type/voucher materials of Plesioschistorchis manteri (Gupta & Tandon, 1984) n. comb. and Schistorchis paruchini Kurochkin, 1974; (2) elucidating the life histories (i.e. intermediate hosts) of members of the Postporinae Yamaguti, 1958 and Schistorchiinae; and (3) generating DNA sequence data for more species of megaperids to help future workers produce increasingly accurate taxonomic classifications that better reflect phylogenetic relationships within this ecologically diverse group of digeneans.
References
Bravo-Hollis, M. & Manter, H.W. (1957) Trematodes of marine fishes of Mexican waters. X. Thirteen Digenea, including nine new species and two new genera, from the Pacific coast. Proceedings of the Helminthological Society of Washington, 24, 35–48.
Bray, R.A. (2005a) Superfamily Lepocreadioidea Odhner, 1905. 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. 541–543.
Bray, R.A. (2005b) Family Megaperidae Manter, 1934. 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. 683–685.
Bush, A.O., Lafferty, K.D., Lotz, J.M. & Shostak, A.W. (1997) Parasitology meets ecology on its own terms: Margolis et al. revisited. Parasitology, 83, 575–583.
https://doi.org/10.2307/3284227Cable, R.M. (1954) Studies of marine digenetic trematodes of Puerto Rico. The life cycle in the family Megaperidae. Journal of Parasitology, 40, 202–208.
https://doi.org/10.2307/3274300Cribb, T.H. (2005) Family Apocreadiidae Skrjabin, 1942. 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. 621–639.
Cribb, T.H. & Bray, R.A. (1999) A review of the Apocreadiidae Skrjabin, 1942 (Trematoda: Digenea) and description of Australian species. Systematic Parasitology, 44, 1–36.
https://doi.org/10.1023/a:1006197201426Cribb, 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, 1–7.
https://doi.org/10.1007/s11230-010-9229-zCribb, T.H. & Gibson, D.I. (2017a) Schistorchis Lühe in Herdman, 1906. World Register of Marine Species (WoRMS). Available from: http://www.marinespecies.org/aphia.php?p=taxdetails&id=574207 (accessed 6 September 2017)
Cribb, T.H. & Gibson, D.I. (2017b) Postporus Manter, 1949. World Register of Marine Species (WoRMS). Available from: http://www.marinespecies.org/aphia.php?p=taxdetails&id=415856 (accessed 6 September 2017)
Curran, S.S., Tkach, V.V. & Overstreet, R.M. (2013) Molecular evidence for two cryptic species of Homalometron (Digenea: Apocreadiidae) in freshwater fishes of the southeastern United States. Comparative Parasitology, 80, 186–195.
https://doi.org/10.1654/4626.1Dollfus, R.P. (1950) Trématodes récoltés au Congo Belge par Professeur Paul Brien (mai–août 1937). Annales du Muséum du Congo Belge, Tervuren, C: Zoologie, Series 5, 1, 1–136.
Dronen, N.O., Blend, C.K., Khalifa, R.M.A., Mohamadain, H.S. & Karar, Y.F.M. (2016) Pelopscreadium aegyptense n. gen., n. sp. and Pelopscreadium spongiosum (Bray & Cribb, 1998) n. comb., (Digenea: Lepocreadiidae), each from disjunct populations of the yellow boxfish, Ostracion cubicus Linnaeus (Ostraciidae). Zootaxa, 4127 (3), 567–578.
https://doi.org/10.11646/zootaxa.4127.3.9Fayton, T.J., Curran, S.S., Andres, M.J., Overstreet, R.M. & McAllister, C.T. (2016) Two new species of Homalometron (Digenea; Apocreadiidae) from Nearctic freshwater fundulids, elucidation of the life cycle of H. cupuloris, and molecular phylogenetic analysis of some congeners. Journal of Parasitology, 102, 94–104.
https://doi.org/10.1645/15-862Froese, R. & Pauly, D. (Eds.) (2017) FishBase. Version 06/2017. Available from: http://www.fishbase.org (accessed 4 September 2017)
Garcia, L.S. & Ash, L.R. (1979) Diagnostic Parasitology: Clinical Laboratory Manual. 2nd Edition. The C.V. Mosby Company, London, 182 pp.
Gupta, S.P. & Tandon, V.L. (1984) On some trematode parasites from marine fishes of Puri, Orissa. Indian Journal of Helminthology, 36, 143–161.
Hafeezullah, M. (1981) Schistorchiid trematodes of marine fishes of India, with considerations on the status of the genus Megacreadium Nagaty, 1956 and Family Schistorchiidae Yamaguti, 1942. Bulletin of the Zoological Survey of India, 3, 167–177.
Hanson, M.L. (1953) A discussion of the trematode genus Schistorchis (Family Lepocreadiidae) with descriptions of two new species from Hawaii. Pacific Science, 7, 447–452.
Hopkins, S.H. (1937) A new type of allocreadiid cercaria: the cercariae of Anallocreadium and Microcreadium. Journal of Parasitology, 23, 94–97.
https://doi.org/10.2307/3272032International Commission of Zoological Nomenclature. (1999) International Code of Zoological Nomenclature, 4th Edition. International Trust for Zoological Nomenclature, London, 336 pp. [Ride, W.D.L., Cogger, H.G., Dupuis, C., Kraus, O., Minelli, A., Thompson, F.C. & Tubbs, P.K. (Eds.)]
https://doi.org/10.5962/bhl.title.50608Johnston, S.J. (1913) On some Queensland trematodes, with anatomical observations and descriptions of new species and genera. Quarterly Journal of Microscopical Science, 59, 361–400.
Jones, A. (2005) Introduction and key to superfamilies. 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. 1–4.
Kurochkin, Y.V. (1974) A new trematode species of the genus Schistorchis (Trematoda: Schistorchidae) from Navodon australis in the Great Australian Bight. Izvestiya Tikhookeanskogo Instituta Rybnogo Khoziaĭstva i Okeanografii, 88, 67–68. [in Russian]
Lieske, E. & Myers, R. (1994) Collins Pocket Guide. Coral Reef Fishes: Indo-Pacific & Caribbean including the Red Sea. Harper Collins, London, 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.W. (1901) Parasites of fishes of the Woods Hole region. Bulletin of the United States Fish Commission for 1899, 19, 405–492.
https://doi.org/10.5962/bhl.title.11834Linton, E.W. (1907) Notes on parasites of Bermuda fishes. Proceedings of the U.S. National Museum, 33, 85–126.
https://doi.org/10.5479/si.00963801.33-1560.85Lühe, M.F.L. (1906) Report on the trematode parasites from the marine fishes of Ceylon. The Royal Society Report on the Pearl Oyster Fisheries, 5, 97–108.
Machida, M. & Kuramochi, T. (1999) Digenean trematodes from tetraodontiform fishes from Japanese and adjacent waters. Bulletin of the National Science Museum, Series A, Zoology, 25, 1–25.
Manter, H.W. (1933) A new family of trematodes from marine fishes. Transactions of the American Microscopical Society, 52, 233–242.
https://doi.org/10.2307/3222258Manter, H.W. (1934) Megapera, new name for the trematode genus Eurypera Manter, 1933. Transactions of the American Microscopical Society, 53, 293.
https://doi.org/10.2307/3222107Manter, H.W. (1936) Some trematodes of cenote fish from Yucatan. Publications of the Carnegie Institution of Washington, 457, 33–38.
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. (1947) The digenetic trematodes of marine fishes of Tortugas, Florida. American Midland Naturalist, 38, 257–416. https://doi.org/10.2307/2421571
Manter, H.W. (1949) An additional trematode from Tortugas, Florida, and a new name for Opisthoporus Manter, 1947, preoccupied. American Midland Naturalist, 41, 432–435.
https://doi.org/10.2307/2421722Manter, H.W. (1954) Some digenetic trematodes from fishes of New Zealand. Transactions of the Royal Society of New Zealand, 82, 475–568.
Manter, H.W. (1963) Studies on digenetic trematodes of fishes of Fiji. II. Families Lepocreadiidae, Opistholebetidae, and Opecoelidae. Journal of Parasitology, 49, 99–113.
https://doi.org/10.2307/3275683Martin, W.E. (1958) Hawaiian helminths 1. Trigonocryptus conus n. gen., n. sp. (Trematoda: Fellodistomidae). Pacific Science, 12, 251–254.
Nagaty, H.F. (1956) Trematodes of fishes from the Red Sea. Part 6. On five distomes including one new genus and four new species. Journal of Parasitology, 42, 151–155.
https://doi.org/10.2307/3274728Nagaty, H.F. (1957) Trematodes of fishes from the Red Sea. Part 8. Five species in the families Schistorchidae, Acanthocolpidae, and Heterophyidae. Journal of Parasitology, 43, 217–220.
https://doi.org/10.2307/3274653Nagaty, H.F. & Abdel-Aal, T. (1962) Trematodes of fishes from the Red Sea. Part 17. On three allocreadiid sp. and one schistorchiid sp. Journal of the Arab Veterinary Medical Association, 22, 307–314.
Odhner, T. (1928) Weitere Trematoden mit anus. Akriv för Zoologi, 20, 1–6.
Oshmarin, P.G., Mamaev, Yu.L. & Parukhin, A.M. (1961) New species of trematodes of the family Diploproctodaeidae Ozaki, 1928. Helminthologia, 3, 254–260.
Ostrowski de Núñez, M., Brugni, N. & Flores, V.R. (2003) Posterotestes unelen gen. et sp. n. (Digenea: Apocreadiidae) from Percichthys trucha (Osteichthyes: Percichthyidae) in Patagonia, Argentina. Folia Parasitologia, 50, 211–214. https://doi.org/10.14411/fp.2003.037
Parukhin, A.M. (1963) New species of trematodes from fish of the South China Sea. In: Skjrabin, K.I. (Ed.), Helminths of man, animals and plants and their control: Papers on helminthology presented to Academician K.I. Skrjabin on his 85th birthday. Izdatelstov Akadémie Nauk, SSSR, Moscow, pp. 123–125. [in Russian]
Price, E.W. (1932) The trematode parasites of marine mammals. Proceedings of the United States National Museum, 81, 1–68. https://doi.org/10.5479/si.00963801.81-2936.1
Pulis, E.E., Curran, S.S., Andres, M.J. & Overstreet, R.M. (2014) Change in rank of Megaperidae (Trematoda) to Megaperinae within the Apocreadiidae and description of Haintestinum amplum n. g., n. sp. Parasitology International, 63, 269–274.
https://doi.org/10.1016/j.parint.2013.11.007Siddiqi, A.H. & Cable, R.M. (1960) Digenetic trematodes of marine fishes of Puerto Rico. Scientific Survey of Porto Rico and the Virgin Islands, 17, 257–369.
Simer, P.H. (1929) Fish trematodes from the lower Tallahatchie River. American Midland Naturalist, 11, 563–588.
https://doi.org/10.2307/2420148Skjrabin, K.I. (1964) Keys to the trematodes of animals and man, University of Illinois Press, Urbana, 351 pp.
Sogandares-Bernal, F. (1959) Digenetic trematodes of marine fishes from the Gulf of Panama and Bimini, British West Indies. Tulane Studies in Zoology, 7, 69–117.
Sogandares-Bernal, F. & Hutton, R.F. (1959) Studies on helminth parasites of the coast of Florida I. Digenetic trematodes of marine fishes from Tampa and Boca Ciega Bays with descriptions of two new species. 1. Bulletin of Marine Science of the Gulf and Caribbean, 9, 53–68.
Stafford, J. (1904) Trematodes from Canadian fishes. Zoologischer Anzeiger, 27, 481–495.
Stunkard, H.W. (1964) The morphology, life-history, and systematics of the digenetic trematode, Homalometron pallidum Stafford, 1904. Biological Bulletin, 126, 163–173.
https://doi.org/10.2307/1539426Szidat, L. (1954) Trematodos nuevos de peces de agua dulce de la República Argentina y un intento para aclarar su carácter marino. Revista del Instituto Nacional de Investigacion de las Ciencias Naturales y Museo Argentino de Ciencias Naturales "Bernardino Rivaldavia", Ciencias Zoologicas, 3, 1–85.
Toman, G. (1989) Digenetic trematodes of marine teleost fishes from the Seychelles, Indian Ocean. II. Acta Parasitologica Polonica, 34, 235–246.
Yamaguti, S. (1937) Studies on the helminth fauna of Japan. Part 17. Trematodes of a marine fish, Branchiostegus japonicus (Houttuyn). Published by author, Kyoto, 15 pp.
Yamaguti, S. (1942) Studies on helminth fauna of Japan. Part 39. Trematodes of fishes mainly from Naha. Transactions of the Biogeographical Society of Japan, 3, 329–398.
Yamaguti, S. (1952) Parasitic worms mainly from Celebes. Part 1. New digenetic trematodes of fishes. Acta Medica Okayama, 8, 146–198.
Yamaguti, S. (1958) Systema Helminthum. Vol 1. The digenetic trematodes of vertebrates. Part 1. Interscience Publishers, New York, 979 pp.
Yamaguti, S. (1971) Synopsis of digenetic trematodes of vertebrates. Vol. 1. Keigaku Publishing Company, Tokyo, 1074 pp.
Yamaguti, S. (1975) A synoptic review of life histories of digenetic trematodes with special reference to the morphology of their larval forms. Keigaku Publishing Company, Tokyo, 590 pp.