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NAS - Nonindigenous Aquatic Species |
Common Name: cestode
Synonyms and Other Names: S. polymorphus
Identification: S. pleuronectis refers to a complex of species of cestodes in the order Tetraphyllidea. They exhibit proglottids containing male and female genitalia that can be shed to develop into new individuals. Plerocercoids and adults have a scolex for attachment to the host with various bothridia (hooked holdfasts) and an accessory apical sucker. The number of loculi per bothridium has been recorded to range from 1-74 in species from around the world. Larvae can encyst as metacestodes in some hosts and are difficult to identify at this stage (Anantaraman 1963; Avdeeva and Avdeev 1980; Post 1983; Radhakrishnan et al. 1984; Wojciechowska 1990; Pronin et al. 1997; Chambers et al. 2000; Fernandez et al. 2004).
Size information is lacking for S. pleuronectis collected from the Great Lakes basin. However, other species in this group can measure 0.1-8.8 mm in length by ‹0.1-0.4 mm in width. Measurements vary according to whether or not the worm is relaxed and its life history stage, and whether width is measured at the apical sucker or in the middle of the worm (Anantaraman 1963; Reimer 1977; Radhakrishnan et al. 1984; Wojciechowska 1990; Chambers et al. 2000).
Size: 0.1-8.8 mm in length by ‹0.1-0.4 mm in width
Native Range:
As a species complex, S. pleuronectis is cosmopolitan in distribution. Little is known about individual species’ ranges within this group. However, it is known that at least one species in this group occurs in the Black Sea watershed using the round goby (Neogobius melanostomus) as its host (Pronin et al. 1997).
Nonindigenous Occurrences: S. pleuronectis plerocercoids were first collected from the Lake St. Clair watershed in 1994 (Pronin et al. 1997).
Ecology: Plerocercoids in the species complex S. pleuronectis were found in the intestinal walls of two individual N. melanostomus collected from the Lake St. Clair watershed. For some tetraphyllidean species it is known that copepods are common intermediate hosts. This group is very common in diadromous, marine and brackish water fish species, including those in the families Cottidae, Salmonidae, and Clupeidae. Each proglottid of a cestode is a single unit containing all reproductive organs for development in a host (Anantaraman 1963; Post 1983; Groenewold et al. 1996; Pronin et al. 1997). Species within this group have been recorded in the Atlantic Ocean, the Pacific Ocean, the Mediterranean, the Black Sea, the Gulf of St. Lawrence and St. Lawrence estuary, and rivers on the east coast of North America. They occur in at least 60 species of teleost fishes from the Atlantic Ocean alone. They also occur in marine mammals and various invertebrates (Anantaraman 1963; Rosenthal 1967; Brooks and Brothers 1974; Radhakrishan et al. 1984; Scott 1988; Landry et al. 1992; Hogans et al. 1993; Reimer 1993; Arthur et al. 1995; Groenewold et al. 1996; Moran et al. 1996; Chambers et al. 2000; Gonzalez and Kroeck 2000; Oliva 2001; Moravec 2003; Fernandez et al. 2003, 2004; O’Connell and Fives 2004; Tavares et al. 2004).
Means of Introduction: The species was likely introduced with N. melanostomus to the Lake St. Clair watershed in ships’ ballast water (Pronin et al. 1997).
Status: Established where recorded.
Impact of Introduction:
A) Realised: None.
B) Potential: It is unlikely that any nonindigenous parasites, this one included, can regulate N. melanostomus populations in the Great Lakes drainage (Pronin et al. 1997).
Remarks: In 1788, Mueller proposed to name a group of metacestodes from intestines of teleost fish as S. pleuronectis. In 1819, Rudolphi, who doubted whether this species was valid, chose S. polymorphus to synonymize these species. Scientists have gradually realized that these two names actually include a large number of tetraphyllidean metacestodes (Chambers et al. 2000).
References
Anantaraman, S. 1963. Larval cestodes in marine invertebrates and fishes with a discussion of the life cycles of the Tetraphyllidea and the Trypanorhyncha. Z. f. Parasitenkunde 23:309-314.
Avdeeva, N. V. and V. V. Avdeev. 1980. Peculiarities of morphogenesis of adhesive organs of some plerocercoids of the collective genus Scolex (Tetraphyllidea) and their identification. Parazitologiya 14:242-250.
Brooks, D. R. and E. B. Brothers. 1974. Helminths of three species of goby (Pisces: Gobiidae) from Mission Bay, San Diego. The Journal of Parasitology 60(6):1062-1063.
Chambers, C. B., T. H. Cribb, and M. K. Jones. 2000. Tetraphyllidean metacestodes of teleosts of the Great Barrier Reef, and the use of in vitro cultivation to identify them. Folia Parasitologica 47:285-292.
Fernandez, M., C. Agusti, F. Javier Aznar, and J. Antonio Raga. 2003. Gastrointestinal helminths of Risso’s dolphin Grampus griseus from the Western Mediterranean. Diseases of Aquatic Organisms 55(1):73-76.
Fernandez, M., F. Javier Aznar, F. E. Montero, B. B. Georgiev, and J. A. Raga. 2004. Gastrointestinal helminths of Cuvier’s beaked whales, Ziphius cavirostris, from the western Mediterranean. Journal of Parasitology 90(2):418-420.
Gonzalez, R. A. and M. A. Kroeck. 2000. Enteric helminths of the shortfin squid Illex argentinus in San Matias Gulf (Argentina) as stock discriminants. Acta Parasitologica 45(2):89-93.
Groenewold, S., R. Bergham, and C.-D. Zander. 1996. Parasite communities of four fish species in the Wadden Sea and the role of fish discarded by the shrimp fisheries in parasite transmission. Helgolander Meeresunters 50:69-85.
Hogans, W. E., M. J. Dadswell, L. S. Uhazy, and R. G. Appy. 1993. Parasites of American shad, Alosa sapidissima (Osteichthyes: Clupeidae), from rivers of the North American Atlantic coast and the Bay of Fundy, Canada. Canadian Journal of Zoology 71(5):941-946.
Landry, T., A. D. Boghen, and G. M. Hare. 1992. Parasites of the blueback herring (Alosa aestivalis) and of the alewife (Alosa pseudoharengus) of the Miramichi River, New Brunswick. Canadian Journal of Zoology 70(8):1622-1624.
Moran, J. D. W., J. R. Arthur, and M. D. B. Burt. 1996. Parasites of sharp-beaked redfishes (Sebastes fasciatus and Sebastes mentella) collected from the Gulf of St. Lawrence, Canada. Canadian Journal of Fisheries and Aquatic Sciences 53:1821-1826.
Moravec, F. 2003. Observations on the metazoan parasites of the Atlantic salmon (Salmo salar) after its reintroduction into the Elbe River basin in the Czech Republic. Folia Parasitologica (Ceske Budejovice) 50(4):298-304.
O’Connell, M. P. and J. M. Fives. 2004. Helminth communities of the lesser sandell Ammodytes tobianus L. off the west coast of Ireland. Journal of Parasitology 90(5):1058-1061.
Oliva, M. E. 2001. Metazoan parasites of Macruronus magellanicus from southern Chile as biological tags. Journal of Fish Biology 58:1617-1622. Post, G. 1983. Textbook of Fish Health. T. F. H. Publications, Inc. Ltd., The British Crown Company of Hong Kong. 256 pp.
Pronin, N. M., G. W. Fleischer, D. R. Baldanova, and S. V. Pronina. 1997. Parasites of the recently established round goby (Neogobius melanostomus) and tubenose goby (Proterorhinus marmoratus) (Gobiidae) from the St. Clair River and Lake St. Clair, Michigan, USA. Folia Parasitologica (Ceske Budejovice) 44(1):1-6.
Radhakrishnan, S., N. B. Nain, and N. K. Balasubramanian. 1984. Nature of infection of Trichiurus lepturus (Pisces: Trichiuridae) by Scolex pleuronectis (Cestoda: Tetraphyllidea). Archiv fuer Hydrobiologie 99(2):254-267.
Reimer, L. W. 1977. Larval cestodes in plankton invertebrates of the Atlantic near the shore of north-west Africa. Parazitologiia 11(4):309-315.
Reimer, L. W. 1993. Parasites of Merluccius capensis and Merluccius paradoxus from the coast of Namibia. Applied Parasitology 34(2):143-150.
Rosenthal, H. 1967. Parasites in larvae of the herring (Clupea harengus L.) fed with wild plankton. Marine Biology 1:10-15.
Scott, J. S. 1988. Helminth parasites of redfish Sebastes fasciatus from the Scotian Shelf, Bay of Fundy, and eastern Gulf of Maine, Nova Scotia, Canada. Canadian Journal of Zoology 66(3):617-621.
Tavares, L. E. R., A. J. A. Bicudo, and J. L. Luque. 2004. Metazoan parasites of needlefish Tylosurus acus (Lacepede, 1803) (Osteichthyes: Belonidae) from the coastal zone of the State of Rio de Janeiro, Brazil. Revista Brasileira de Parasitologia Veterinaria 13(1):36-40.
Wojciechowska, A. 1990. Onchobothrium antarcticum new species Tetraphyllidea from Bathraja eatonii Gunther, 1876 and a pleurocercoid from Notothenioidea, South Shetlands, Antarctica. Acta Parasitologica Polonica 35(2):113-118.
Author: Rebekah M. Kipp
Contributing Agencies: NOAA - GLERL
Revision Date: 5/28/2007 Citation for this information:
Rebekah M. Kipp. 2009. Scolex pleuronectis. USGS Nonindigenous Aquatic Species Database, Gainesville, FL.
<http://nas.er.usgs.gov/queries/FactSheet.asp?speciesID=2722> Revision Date: 5/28/2007
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