Microbial Ecology

, Volume 30, Issue 1, pp 79–88 | Cite as

Adaptation of inducible defense in Euplotes daidaleos (Ciliophora) to predation risks by various predators

  • J. Kusch


The extent of induced morphological defense in Euplotes daidaleos correlates to this ciliate's predation risk from the defense-inducing predator species. Euplotes daidaleos responded by morphological transformation only to organisms that are able to feed on typically formed Euplotes cells (63 ± 5 μm cell width in E. daidaleos). Three of those potential predator species caused defensive changes to various degrees (Student's t-test, P < 0.1 to P < 0.0001): Lembadion bullinum (Ciliata) induced 82 ± 6 μm cell width in E. daidaleos; Chaetogaster diastrophus (Oligochaeta) induced 85 = 6 μm width; and Stenostomum sphagnetorum (Turbellaria) induced 89 ± 8 μm width (at a density of 10 predators per milliliter, respectively). At higher predator densities (50 or 100 organisms per milliliter), Euplotes developed a correspondingly larger width (to a maximum of 103 ± 10 μm in the presence of S. sphagnetorum). Euplotes did not respond to organisms (e.g., Blepharisma japonicum, Colpidium campylum, Didinium nasutum, Paramecium caudatum, Spirostomum ambiguum, Stentor coeruleus) that cannot feed on this ciliate species. Daphnia longispina and Bursaria truncatella predators, which can feed on large prey of ≥125, or ≥200 μm in diameter, respectively, also had no effect on the morphology of Euplotes. The extent of defense in Euplotes that was induced by 10 predators per milliliter during 24 h decreased the predation risk from those predators to 67% in the presence of S. sphagnetorum, to 50% with L. bullinum, and to 15% with C. diastrophus, compared to the typical form of Euplotes. In a natural population, the defensive form of E. daidaleos was found with average cell widths of 88 ± 8 μm. The results indicate that predator-induced defense in natural Euplotes populations is beneficial to this prey and that it is adapted to the predation abilities of Euplotes predators, whereby energetical costs related to defensive changes may be saved.


Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.


  1. 1.
    Beauchamp, P De (1952) Un facteur de la variabilité chez les Rotifères du genre Brachionus. Compt Rend Soc Biol 234:573–575Google Scholar
  2. 2.
    Brönmark C, Miner JG (1992) Predator-induced phenotypical change in body morphology in crucian carp. Science 258:1348–1350Google Scholar
  3. 3.
    Dodson S (1988) The ecological role of chemical stimuli for the zooplankton: predator-avoidance behavior in Daphnia. Limnol Oceanogr 33:1431–1439Google Scholar
  4. 4.
    Finlay BJ, Clarke KJ, Cowling AJ, Hindle RM, Rogerson A (1988) On the abundance and distribution of protozoa and their food in a productive freshwater pond. Euro J Protistol 23:205–217Google Scholar
  5. 5.
    Gilbert JJ, Stemberger RS (1984) Asplanchna-induced polymorphism in the rotifer Keratella slacki. Limnol Oceanogr 29:1309–1316Google Scholar
  6. 6.
    Grant JWG, Bayly IAE (1981) Predator induction of crests in morphs of the Daphnia carinata King complex. Limnol Oceanogr 26:201–218Google Scholar
  7. 7.
    Halbach U (1969) Räuber und ihre Beute: Der Anpassungswert von Dornen bei Rädertieren. Naturwissenschaften 56:142–143Google Scholar
  8. 8.
    Halbach U (1971): Zum Adaptivwert der zyklomorphen Dornenbildung von Brachionus calyciflorus Pallas (Rotatoria). Oecologia 6:267–288Google Scholar
  9. 9.
    Harvell CD (1984) Predator-induced defense in a marine bryozoan. Science 224:1357–1359Google Scholar
  10. 10.
    Harvell CD (1990) The ecology and evolution of inducible defenses. Q Rev Biol 65:323–340Google Scholar
  11. 11.
    Havel JE (1987) Predator-induced defenses: a review. In: Kerfoot WC, Sib A (eds) Predation, direct and indirect impacts on aquatic communities. University Press of New England, Hanover, London, pp 263–278Google Scholar
  12. 12.
    Heckmann K (1995) Räuber-induzierte Feindabwehr bei Protozoen. Naturwissenschaften 82: 107–116Google Scholar
  13. 13.
    Jerka-Dziadosz M, Dosche C, Kuhlmann H-W, Heckmann K (1987) Signal-induced reorganization of the microtubular cytoskeleton in the ciliated protozoon Euplotes octocarinatus. J Cell Sci 87:555–564Google Scholar
  14. 14.
    Krueger DA, Dodson SI (1981) Embryological induction and predation ecology in Daphnia pulex. Limnol Oceanogr 26:219–223Google Scholar
  15. 15.
    Kuhlmann H-W (1994) Escape response of Euplotes octocarinatus to turbellarian predators. Arch Protistenkd 144:163–171Google Scholar
  16. 16.
    Kuhlmann H-W, Heckmann K (1985) Interspecific morphogens regulating prey-predator relationships in protozoa. Science 227:1347–1349Google Scholar
  17. 17.
    Kuhlmann H-W, Heckmann K (1994) Predation risk of typical ovoid and “winged” morphs of Euplotes (Protozoa, Ciliophora). Hydrobiologia 284:219–227Google Scholar
  18. 18.
    Kusch J (1993): Induction of defensive morphological changes in ciliates. Oecologia 94:571–575.Google Scholar
  19. 19.
    Kusch J (1993): Behavioural and morphological changes in ciliates induced by the predator Amoeba proteus. Oecologia 96:354–359Google Scholar
  20. 20.
    Kusch J (1993) Predator-induced morphological changes in Euplotes (Ciliata): isolation of the inducing substance from Stenostomum sphagnetorum (Turbellaria). J Exp Zool 265:613–618Google Scholar
  21. 21.
    Kusch J (1994) Predator-released factors that induce defensive responses in Euplotes. In: Hausmann K, Hüsmann N (eds) Progress in protozoology. Fischer Verlag, Jena, New York, pp 56–58Google Scholar
  22. 22.
    Kusch J, Heckmann K (1992) Isolation of the Lembadion-factor, a morphogenetically active signal, that induces Euplotes cells to change from their ovoid form into a larger lateral winged morph. Dev Genet 13:241–246Google Scholar
  23. 23.
    Kusch J, Kuhlmann H-W (1994) Cost of Stenostomum-induced morphological defense in the ciliate Euplotes octocarinatus. Arch Hydrobiol 130:257–267Google Scholar
  24. 24.
    Lampert W (1993) Ultimate causes of diel vertical migration of zooplankton: new evidence for the predator-avoidance hypothesis. Arch Hydrobiol Beih 39:79–88Google Scholar
  25. 25.
    Lampert W, Tollrian R, Stibor H (1994) Chemische Induktion von Verteidigungsmechanismen bei Süsswassertieren. Naturwissenschaften 81:375–382Google Scholar
  26. 26.
    Larsson P, Dodson S (1993) Chemical communication in planktonic animals. Arch Hydrobiol 129:129–155Google Scholar
  27. 27.
    Lively CM (1986) Predator-induced shell dimorphism in the acorn barnacle Chthamalus anisopoma. Evolution 40:232–242Google Scholar
  28. 28.
    Loose CJ (1993) Daphnia diel vertical migration behavior: response to vertebrate predator abundance. Arch Hydrobiol Beih 39:29–36Google Scholar
  29. 29.
    Lüning J (1992) Phenotypic plasticity of Daphnia pulex in the presence of invertebrate predators: morphological and life history response. Oecologia 92:383–390Google Scholar
  30. 30.
    Reukauf E (1930) Zur Biologie von Didinium nasutum Stein. Z Vergl Physiol 11:689–701Google Scholar
  31. 31.
    Schönborn W (1984) The annual energy transfer from the communities of ciliata to the population of Chaetogaster diastrophus (Gruithuisen) in the river Saale. Limnologica 16:15–23Google Scholar
  32. 32.
    Washburn JO, Gross ME, Mercer DR, Anderson JR (1988) Predator-induced trophic shift of a free-living ciliate: parasitism of mosquito larvae by their prey. Science 240:1193–1195Google Scholar
  33. 33.
    Wicklow BJ (1988) Developmental polymorphism induced by intraspecific predation in the ciliated protozoon Onychodromus quadricornutus. J Protozool 35:137–141Google Scholar

Copyright information

© Springer-Verlag New York Inc 1995

Authors and Affiliations

  • J. Kusch
    • 1
  1. 1.Institute for General Zoology and GeneticsUniversity of MünsterGermany

Personalised recommendations