, Volume 210, Issue 3, pp 233–242 | Cite as

The diatoms ingested by freshwater snails: temporal, spatial, and interspecific variation

  • Robert T. DillonJr.
  • Kevin B. Davis


Seventeen species of diatoms, representing a broad range of sizes, shapes, and growth habits, were collected from rocks in rapidly-flowing sections of the Mitchell River, North Carolina. The diatoms ingested by adult Goniobasis proxima, juvenile Leptoxis carinata, and adult Physa sp. co-occurring in this habitat were indistinguishable from one another, in spite of great differences in radular morphology. All snails sampled the diatom flora almost randomly, with only one or two of the larger diatom species under-represented in the gut contents. Some snails also seemed to selectively ingest the smaller individuals of the larger diatom taxa, and larger individuals of the smaller diatom taxa. The diatoms identifiable in juvenile Goniobasis guts were somewhat more distinctive, although this seemed to be due at least partly to more mechanical breakage. The diatom flora of quiet, muddy pools was much different from that of shallow, rocky areas, but once again, Goniobasis seemed to sample the available flora randomly. Seasonal variation was also apparent in the diatom diet of Goniobasis. We suggest that in some cases, it may be reasonable to use snails to sample the diatom assemblage present in a particular habitat, if more direct methods are impractical.

Key words

diatoms grazing freshwater snails radula periphyton 


Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.


  1. Aldridge, D. W., 1982. Reproductive tactics in relation to life-cycle bioenergetics in three natural populations of the freshwater snail, Leptoxis carinata. Ecology 63: 196–208.Google Scholar
  2. Blum, J. L., 1956. The ecology of river algae. Bot. Rev. 22: 291–341.Google Scholar
  3. Calow, P., 1970. Studies on the natural diet of Lymnaea pereger obtusa and its possible ecological implications. Proc. Malacol. Soc. London 39: 203–215.Google Scholar
  4. Calow, P., 1973a. The food of Ancylus fluviatilis (Mull.), a littoral, stone-dwelling, herbivore. Oecologia (Berl.) 13: 113–133.Google Scholar
  5. Calow, P., 1973b. Field observations and laboratory experiments on the general food requirements of two species of freshwater snail, Planorbis contortus and Ancylus fluviatilis.Proc. Malacol. Soc. London 40: 483–489.Google Scholar
  6. Calow, P., 1974. Evidence for bacterial feeding in Planorbis contortus L. (Gastropoda: Pulmonata). Proc. Malacol. Soc. London 41: 145–156.Google Scholar
  7. Calow, P. & C. R. Fletcher, 1972. A new radiotracer technique involving 14C and 51Cr, for estimating the assimilation efficiencies of aquatic, primary consumers. Oecologia (Berl.) 9: 155–170.Google Scholar
  8. Cattaneo, A. & J. Kalff, 1986. The effect of grazer size manipulation on periphyton communities. Oecologia (Berl.) 69: 612–617.Google Scholar
  9. Clampitt, P. T., 1970. Comparative ecology of the snails Physa gyrina and Physa integra. Malacologia 10: 113–151.Google Scholar
  10. Cuker, B. E., 1983. Grazing and nutrient interactions in controlling the activity and composition of the epilithic community of an arctic lake. Limnol. Oceanogr. 28: 133–141.Google Scholar
  11. Cummins, K. W. & M. J. Klug, 1979. Feeding ecology of stream invertebrates. Annu. Rev. Ecol. Syst. 10: 147–172.CrossRefGoogle Scholar
  12. Dazo, B. C., 1965. The morphology and natural history of Pleurocera acuta and Goniobasis livescens (Gastropoda: Cerithiacea: Pleuroceridae). Malacologia 3: 1–80.Google Scholar
  13. DeWitt, R. M., 1955. The ecology and life history of the pond snail, Physa gyrina. Ecology 36:40–44.Google Scholar
  14. Dillon, R. T. Jr., 1981. Patterns in the morphology and distribution of gastropods in Oneida Lake, NY, detected using computer-generated null hypotheses. Am. Nat. 118: 83–101.CrossRefGoogle Scholar
  15. Dillon, R. T. Jr., 1982. The correlates of divergence in isolated populations of the freshwater snail, Goniobasis proxima. Ph.D. thesis, The University of Pennsylvania, Philadelphia, 183 pp.Google Scholar
  16. Dillon, R. T. Jr., 1984. Geographic distance, environmental difference, and divergence between isolated populations. Syst. Zool. 33: 69–82.Google Scholar
  17. Dillon, R. T. Jr., 1987. A new Monte Carlo method for assessing taxonomic similarity within faunal samples: Reanalysis of the gastropod community of Oneida Lake, NY. Amer. Malacol. Bull. 5: 101–104.Google Scholar
  18. Dillon, R. T. Jr., 1988a. The influence of minor human disturbance on biochemical variation in a population of freshwater snails. Biol. Conserv. 43: 137–144.CrossRefGoogle Scholar
  19. Dillon, R. T. Jr., 1988b. Evolution from transplants between genetically distinct populations of freshwater snails. Genetica 76: 111–119.Google Scholar
  20. Dillon, R. T. Jr. & E. F. Benfield, 1982. Distribution of pulmonate snails in the New River of Virginia and North Carolina: interaction between alkalinity and stream drainage area. Freshwat. Biol. 12: 179–186.Google Scholar
  21. Doremus, C. M. & W. N. Harman, 1977. The effects of grazing by physid and planorbid freshwater snails on periphyton. Nautilus 91: 92–96.Google Scholar
  22. Douglas, B., 1958. The ecology of the attached diatoms and other algae in a small stony stream. J. Ecol. 46: 295–322.Google Scholar
  23. Eichenberger, E., A. Schlatter & H. Weilenmann, 1984. Grazing pressure as a decisive factor in the long-term succession of the benthic vegetation in artificial rivers. Verh. int. Ver. Limnol. 22: 2332–2336.Google Scholar
  24. Elwood, J. W. & D. J. Nelson, 1972. Periphyton production and grazing rates in a stream measured with a 32P material balance method. Oikos 23: 295–303.Google Scholar
  25. Elwood, J. W., J. D. Newbold, A. F. Trimble & R. W. Stark, 1981. The limiting role of phosphorus in a woodland stream ecosystem: effects of P enrichment on leaf decomposition and primary producers. Ecology 62: 146–158.Google Scholar
  26. Gregory, S. V., 1983. Plant-herbivore interactions in stream systems. In J. R. Barnes & G. W. Minshell (eds), Stream ecology, Plenum, New York, 157–189.Google Scholar
  27. Hawkins, C. P. & J. K. Furnish, 1987. Are snails important competitors in stream ecosystems? Oikos 49: 209–220.Google Scholar
  28. Hawkins, C. P., M. L. Murphy & N. H. Anderson, 1982. Effects of canopy, substrate composition, and gradient on the structure of macroinvertebrate communities in Cascade Range streams of Oregon. Ecology 63: 1840–1856.Google Scholar
  29. Hickman, C. S. & T. E. Morris, 1985. Gastropod feeding tracks as a source of data in analysis of the functional morphology of radulae. Veliger 27: 357–365.Google Scholar
  30. Holm, S., 1979. A simple sequentially rejective multiple test procedure. Scand. J. Stat. 6: 65–70.Google Scholar
  31. Hunter, R. D., 1980. Effects of grazing on the quantity and quality of freshwater aufwuchs. Hydrobiologia 69: 251–259.Google Scholar
  32. Jacoby, J. M., 1985. Grazing effects on periphyton by Theodoxus fluviatilis (Gastropoda) in a lowland stream. J. Freshwat. Ecol. 3: 265–272.Google Scholar
  33. Kehde, P. M. & J. L. Wilhm, 1972. The effects of grazing by snails on community structure of periphyton in laboratory streams. Am. Midl. Nat. 87: 8–24.Google Scholar
  34. Kesler, D. H., 1981. Periphyton grazing by Amnicola limosa: An enclosure-exclosure experiment. J. Freshwat. Ecol. 1: 51–59.Google Scholar
  35. Kesler, D. H., E. H. Jokinen & W. R. Munns, Jr., 1986. Trophic preferences and feeding morphology of two pulmonate snail species from a small New England pond, U.S.A. Can. J. Zool. 64: 2570–2575.Google Scholar
  36. Lamberti, G. A., L. R. Ashkenas, S. V. Gregory & A. D. Steinman, 1987. Effects of three herbivores on periphyton communities in laboratory streams. J. N. Am. Benthol. Soc 6: 92–104.Google Scholar
  37. Lang, B. Z., 1968. Note on ecology of Goniobasis proxima in North Carolina. Nautilus 82: 3–5.Google Scholar
  38. Lodge, D. M., 1986. Selective grazing on periphyton: a determinant of freshwater gastropod microdistributions. Freshwat. Biol. 16: 831–841.Google Scholar
  39. Lowe, R. L. & R. D. Hunter, 1988. Effect of grazing by Physa integra on periphyton community structure. J. N. Am. Benthol. Soc 7: 29–36.Google Scholar
  40. McIntire, C. D., 1968. Structural characteristics of benthic algal communities in laboratory streams. Ecology 49: 520–537.Google Scholar
  41. Mulholland, P. J., J. W. Elwood, J. D. Newbold & L. A. Ferren, 1985. Effects of a leaf-shredding invertebrate on organic matter dynamics and phosphorus spiralling in heterotrophic laboratory streams. Oecologia (Berlin) 66: 199–206.Google Scholar
  42. Mulholland, P. J., J. D. Newbold, J. W. Elwood & C. L. Horn, 1983. The effect of grazing intensity on phosphorus spiralling in autotrophic streams. Oecologia (Berlin) 58: 358–366.Google Scholar
  43. Patrick, R., 1970. Benthic stream communities. Am. Sci. 58: 546–549.Google Scholar
  44. Power, M. E., A. J. Stewart & W. J. Matthews, 1988. Grazer control of algae in an Ozark mountain stream: effects of short-term exclusion. Ecology 69: 1894–1898.Google Scholar
  45. Reavell, P. E., 1980. A study of the diets of some British freshwater gastropods. J. Conch. 30: 253–271.Google Scholar
  46. Rice, W. R., 1989. Analyzing tables of statistical tests. Evolution 43: 223–225.Google Scholar
  47. Round, F. E., 1964. The ecology of benthic algae. In D. F. Jackson (eds.) Algae and man. Plenum, New York, pp. 138–184.Google Scholar
  48. Round, F. E., 1973. The biology of the algae, second edition. Edward Arnold, London, 278 pp.Google Scholar
  49. Siegel, S., 1956. Nonparametric statistics for the behavioral sciences. McGraw-Hill, N.Y. 312 pp.Google Scholar
  50. Sokal, R. R. & F. J. Rohlf, 1969. Biometry. W. H. Freeman, San Francisco, 776 pp.Google Scholar
  51. Steinman, A. D. & C. D. McIntire, 1986. Effects of current velocity and light energy on the structure of periphyton assemblages in laboratory streams. J. Phycol. 22: 352–361.Google Scholar
  52. Summer, W. T. & C. D. McIntire, 1982. Grazer-periphyton interactions in laboratory streams. Arch. hydrobiol. 93: 135–157.Google Scholar
  53. Te, G. A., 1980. New classification system for the family Physidae. Arch molluskenkd 110: 179–184.Google Scholar
  54. Thomas, J. D., D. I. Nwanko & P. R. Sterry, 1985. The feeding strategies of juvenile and adult Biomphalaria glabrata (Say) under simulated natural conditions and their relevance to ecological theory and snail control. Proc. r. Soc. London B226: 177–209.Google Scholar

Copyright information

© Kluwer Academic Publishers 1991

Authors and Affiliations

  • Robert T. DillonJr.
    • 1
  • Kevin B. Davis
    • 2
  1. 1.Department of BiologyCollege of CharlestonCharlestonUSA
  2. 2.South Carolina Marine Resources Research InstituteCharlestonUSA

Personalised recommendations