Predation by Dugesia polychroa (Platyhelminthes: Tricladida) prevents the establishment of Physa acuta (Gastropoda: Pulmonata) in hard-substratum habitats
More details
Hide details
Department of Environmental Sciences, “Marco Giustini” Ecology Lab, University of L’Aquila, Coppito Science Center, Italy
Limno Consulting, Rome, Italy
Submission date: 2011-11-11
Final revision date: 2012-02-02
Acceptance date: 2012-02-20
Publication date: 2020-04-08
Corresponding author
Paola Lombardo   

Department of Environmental Sciences, “Marco Giustini” Ecology Lab, University of L’Aquila, Coppito Science Center, I-67100 L’Aquila, Italy
Limno Consulting, via Bedollo 303, I-0012 Rome, Italy
Folia Malacol. 2012;20(2):121-134
Despite half a century of research on planarian-gastropod interactions, the population-level impact of planarian predation on littoral pulmonates is not well known. We have quantified the predation of the common lacustrine planaria Dugesia polychroa Schmidt on the ubiquitous snail Physa acuta Drap., a potential keystone grazer in benthic littoral communities, in a high-replicate laboratory experiment. Planarian predation pressure was maintained constant, and experimental populations of P. acuta were size-structured simulating young-rich small groups (re)colonising the habitat (e.g. after release from predation). D. polychroa caused a quick (week 2) reduction in the density of hatchlings and juveniles, followed by significant reduction in the numbers of young (at the onset of reproductive age) and larger, reproductive-age adults (week 3). Planarias did not have any effect on the size of reproductive-age large adults, but oviposition decreased significantly in week 2, and all P. acuta populations in planarian-present aquaria went extinct within six weeks. Dugesiid-induced extinction mainly occurred by precluding population turnover. The results strongly suggest that active predation by D. polychroa on P. acuta can be high under some environmental conditions, effectively preventing the (re)establishment of small, colonising populations of P. acuta in hard-substratum habitats.
Alexander J. E. Jr., Covich A. P. 1991a. Predator avoidance by the freshwater snail Physella virgata in response to the crayfish Procambarus simulans. Oecologia 87: 435-442.
Alexander J. E. Jr., Covich A. P. 1991b. Predation risk and avoidance behavior in two freshwater snails. Biol. Bull. 180: 387-393.
Ball I. R., Reynoldson T. B. 1981. British Planarias, Platyhelminthes, Tricladida: keys and notes for the identification of the species. Cambridge University Press, Cambridge, UK.
Boddington M. J., Mettrick M. F. 1974. The distribution, abundance, feeding habits, and population biology of the immigrant triclad Dugesia polychroa (Platyhelminthes: Turbellaria) in Toronto Harbour, Canada. J. Anim. Ecol. 43: 681-699.
Brönmark C., Malmqvist B. 1986. Interactions between the leech Glossiphonia complanata and its gastropod prey. Oecologia 69: 268-276.
Brönmark C., Weisner S. E. B. 1992. Indirect effects of fish community structure on submerged vegetation in shallow, eutrophic lakes: an alternative mechanism. Hydrobiologia 243/244: 293-301.
Brown K. M., Lydeard C. 2010. Mollusca: Gastropoda. In: Thorp J. H., Covich A. P. (eds). Ecology and classification of North American freshwater invertebrates. 3rd ed., Academic Press/Elsevier, Amsterdam, pp. 277-307.
Cash K. J., McKee M. H., Wrona F. J. 1993. Short- and long-term consequences of grouping and group foraging in the free-living flatworm Dugesia tigrina. J. Anim. Ecol. 62: 529-535.
Cianfanelli S., Lori E., Bodon M. 2007. Non-indigenous freshwater molluscs and their distribution in Italy. In: Gherardi F. (ed.). Biological invaders in inland waters: profiles, distribution and threats. Springer, Dordrecht, pp. 103-121.
Costil K., Clement B. 1996. Relationship between freshwater gastropods and plant communities reflecting various trophic levels. Hydrobiologia 321: 7-16.
Crowl T. A., Covich A. P. 1990. Predator-induced life-history shifts in a freshwater snail. Science 247: 949-951.
Dillon R. T. Jr. 2006. Freshwater gastropoda. In: Sturm C. F., Pearce T. A., Valdés A. (eds). The mollusks: a guide to their study, collection, and preservation. The American Malacological Society, Pittsburgh, PA, pp. 251-259.
Dillon R. T. Jr., Wethington A. R., Rhett J. M., Smith T. P. 2002. Populations of the European freshwater pulmonate Physa acuta are not reproductively isolated from American Physa heterostropha or Physa integra. Invert. Biol. 121: 226-234.
Gaino E., Cianficconi F., Corallini Sorcetti C., Lancioni T., Todini B., Rebora M., Chiappafreddo U., Bicchierai M.C., Spinelli G. 2001. Lago di Piediluco: Monitoraggio della Fauna del Canneto (Poriferi e Macroinvertebrati), 1999-2000. Unpublished report, Dept. Anim. Biol. Ecol., University of Perugia, Italy.
García-Berthou E., Boix D., Clavero M. 2007. Non-indigenous animal species naturalized in Iberian inland waters. In: Gherardi F. (ed.). Biological invaders in inland waters: profiles, distribution and threats. Springer, Dordrecht, pp. 123-140.
Gee R. D., Pickavance J. R., Young J. O. 1998. A comparative study of the population biology of the American immigrant triclad Dugesia tigrina (Girard) in two British lakes. Hydrobiologia 361: 135-143.
Gee R. D., Young J. O. 1993. The food niches of the invasive Dugesia tigrina (Girard) and indigenous Polycelis tenuis Ijima and P. nigra (Müller) (Turbellaria; Tricladida) in a Welsh lake. Hydrobiologia 254: 99-106.
Girod A., Bianchi I., Mariani M. 1980. Guide per il riconoscimento delle specie animali delle acque interne italiane. 7. Gasteropodi, 1. (Pulmonata; Prosobranchia: Neritidae, Viviparidae, Bithyniidae, Valvatidae). CNR Publication # AQ/1/44; Consiglio Nazionale delle Ricerche, Verona.
Glöer P., Meier-Brook C. 2003. Süsswassermollusken. Deutscher Jugendbund für Naturbeobachtung, Hamburg.
Hosper S. H. 1997. Clearing lakes - an ecosystem approach to the restoration and management of shallow lakes in the Netherlands. Institute for Inland Water Management and Waste Water Treatment (RIZA), Lelystad, NL.
Jennings J. B. 1957. Studies on feeding, digestion, and food storage in free-living flatworms (Platyhelminthes: Turbellaria). Biol. Bull. 112: 63-80.
Jones J. I., Young J. O., Haynes G. M., Moss B., Eaton J. W., Hardwick K. J. 1999. Do submerged aquatic plants influence their periphyton to enhance the growth and reproduction of invertebrate mutualists? Oecologia 120: 463-474.
Kefford B. J., Papas P. J., Nugegoda D. 2003. Relative salinity tolerance of macroinvertebrates from the Barwon River, Victoria, Australia. Mar. Freshwater Res. 54: 755-765.
Kelly P. M., Cory J. S. 1987. Operculum closing as a defence against predatory leeches in four British freshwater prosobranch snails. Hydrobiologia 144: 121-124.
Kesler D. H., Munns W. R. Jr. 1989. Predation by Belostoma flumineum (Hemiptera): an important cause of mortality in freshwater snails. J. N. Amer. Benthol. Soc. 8: 342-350.
Kipp R. M. 2007. Dugesia polychroa. USGS Nonindigenenous Aquatic Species Database, Gainesville, FL. Available at [last accessed 10 Feb. 2012].
Koopowitz H. 1970. Feeding behaviour and the role of the brain in the polyclad flatworm, Planocera gilchristi. Anim. Behav. 18: 31-35.
Lombardo P. 1995. Substrate preference of littoral macroinvertebrates during seasonal succession. Unpublished MS Thesis, Kent State University, Kent, OH.
Lombardo P. 2001. Effects of freshwater gastropods on epiphyton, macrophytes, and water transparency under meso- to eutrophic conditions. PhD Dissertation, Kent State University, Kent, OH.
Lombardo P. 2005. Applicability of littoral food-web biomanipulation for lake management purposes: snails, macrophytes, and water transparency in northeast Ohio shallow lakes. Lake Reserv. Manage. 21: 186-202.
Lombardo P., Cooke G. D. 2002. Consumption and preference of selected food types by two freshwater gastropod species. Arch. Hydrobiol. 155: 667-685.
Lombardo P., Giustini M., Miccoli F. P., Cicolani B. 2011a. Fine-scale differences in diel activity among nocturnal freshwater planarias (Platyhelminthes: Tricladida). J. Circad. Rhythms 9: 2.
Lombardo P., Miccoli F. P., Giustini M., Cicolani B. 2011b. Planarian (Dugesia polychroa) predation on freshwater gastropod eggs depends on prey species, clutch morphology, and egg size. Fundam. Appl. Limnol. 178: 325-339.
Macan T. T. 1977. The influence of predation on the composition of fresh-water animal communities. Biol. Rev. 52: 45-70.
Mastrantuono L., Mancinelli T. 2005. Littoral invertebrates associated with aquatic plants and bioassessment of ecological status in Lake Bracciano (Central Italy). J. Limnol. 64: 43-53.
McCollum E. W., Crowder L. B., McCollum S. A. 1998. Complex interactions of fish, snails, and littoral zone periphyton. Ecology 79: 1980-1994.
Michalik-Kucharz A. 2008. The occurrence and distribution of freshwater snails in a heavily industrialised region of Poland (Upper Silesia). Limnologica 38: 43-55.
Moeller R. E., Burkholder J. M., Wetzel R. G. 1988. Significance of sedimentary phosphorus to a submersed freshwater macrophyte (Najas flexilis) and its algal epiphytes. Aquat. Bot. 32: 261-281.
Murdoch W. W., Avery S., Smyth M. E. B. 1975. Switching in predatory fish. Ecology 56: 1094-1105.
Norena Janssen C. 2011. Fauna Europaea: Platyhelminthes: Turbellaria. Fauna Europaea v2.4, [last accessed 10 Feb. 2012].
Perrin N. 1986. Les paramètres du cycle vital de Physa acuta (Gastropoda, Mollusca) en milieu expérimental. Rev. Suisse Zool. 93: 725-736.
Pongratz N., Storhas M., Carranza S., Michiels N. K. 2003. Phylogeography of competing sexual and parthenogenetic forms of a freshwater flatworm: patterns and explanations. BMC Evol. Biol. 3: 23.
Pyefinch K. A. 1937. The fresh and brackish waters of Bardsey Island (North Wales): a chemical and faunistic survey. J. Anim. Ecol. 6: 115-137.
Reavell P. 1980. A study of the diets of some British freshwater gastropods. J. Conchol. 30: 253-271.
Reynoldson T. B. 1977. The population dynamics of Dugesia polychroa (Schmidt) (Turbellaria Tricladida) in a recently constructed Anglesey pond. J. Anim. Ecol. 46: 63-77.
Reynoldson T. B., Young J. O. 1963. The food of four species of lake-dwelling triclads. J. Anim. Ecol. 32: 175-191.
Reynoldson T. B., Young J. O. 1965. Food supply as a factor regulating population size in freshwater triclads. Mitt. Int. Verein. Theor. Angew. Limnol. 13: 3-20.
Seaby R. M. H., Martin A. J., Young J. O. 1995. The reaction time of leech and triclad species to crushed prey and the significance of this for their coexistence in British lakes. Freshwater Biol. 34: 21-28.
Scheffer M. 1998. Ecology of shallow lakes; reprinted with corrections 2004. Kluwer Academic Publishers, Dordrecht.
Sheldon S. P. 1987. The effects of herbivorous snails on submerged macrophyte communities in Minnesota lakes. Ecology 68: 1920-1931.
Taylor D. W. 2003. Introduction to Physidae (Gastropoda: Hygrophila): biogeography, classification, morphology. Rev. Biol. Trop. 51 Suppl. 1: 1-287.
Tripet F., Perrin N. 1994. Size-dependent predation by Dugesia lugubris (Turbellaria) on Physa acuta (Gastropoda): experiments and model. Funct. Ecol. 8: 458-463.
Turner A. W., Fetterolf S. A., Bernot R. J. 1999. Predator identity and consumer behavior: differential effects of fish and crayfish on the habitat use of a freshwater snail. Oecologia 118: 242-247.
Verberk W. C. R. P., Siepel H., Esselink H. 2008. Life-history strategies in freshwater macroinvertebrates. Freshwater Biol. 53: 1722-1738.
Wethington A. R., Lydeard C. 2007. A molecular phylogeny of Physidae (Gastropoda: Basommatophora) based on mitochondrial DNA sequences. J. Moll. Stud. 73: 241-257.
Wilken G. B., Appleton C. C. 1991. Avoidance responses of some indigenous and exotic freshwater pulmonate snails to leech predation in South Africa. S. Afric. J. Zool. 26: 6-10.
Young J. O., Reynoldson T. B. 1999. Continuing dispersal of freshwater triclads (Platyhelminthes; Turbellaria) in Britain with particular reference to lakes. Freshwater Biol. 42: 247-262.
Zar J. H. 2009. Biostatistical Analysis, 5th ed. Prentice Hall/Pearson, Upper Saddle River, NJ.
Differences between two physid species (Gastropoda: Physidae) in antipredator behaviour induced by leeches
Adam Krupski, Tomasz Karasek, Paweł Koperski
Journal of Molluscan Studies
Aplexa hypnorum(Gastropoda: Physidae) exerts competition on two lymnaeid species in periodically dried ditches
Daniel Rondelaud, Philippe Vignoles, Gilles Dreyfuss
Annales de Limnologie - International Journal of Limnology
Journals System - logo
Scroll to top