, Volume 243, Issue 1, pp 269–276 | Cite as

Ecological release in feeding behaviour: the case of bluegills in Japan

  • M. Azuma
Fish and Fisheries


The stomach contents were analyzed monthly for each year-class to elucidate the foraging pattern of bluegills in a small vegetated lake by the frequency occurrence and the ‘points’ methods. Seasonal dietary changes of the year-classes were considered comparing the monthly fluctuations in abundance of major prey organisms. Though these bluegills are dietary generalists and opportunists like those in North America, their foraging pattern was characterized by a relatively clearer dietary shift during ontogeny and a wider food niche including piscivorous than those of bluegills with congeners in their home land. Therefore this finding provides evidence of the ecological release caused by the absence of congeners.

Key words

dietary shifts congener-free conditions habitat use piscivorous ‘points’ method community disturbance 


Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.


  1. Butler, M. J., IV, 1988. In situ observations of bluegill (Lepomis macrochirus Raf.) foraging behavior: the effects of habitat complexity, group size, and predators. Copeia 4: 941–946.Google Scholar
  2. Bulter, M. J., IV, 1989. Community responses to variable predation: field studies with sunfish and freshwater macroinvertebrates. Ecol. Monogr. 59: 311–328.Google Scholar
  3. Crowder, L. B. & W. E. Cooper, 1982. Habitat structural complexity and the interaction between bluegills and their prey. Ecology 63: 1802–1813.Google Scholar
  4. Gerking, S. D., 1962. Production and food utilization in a population of bluegill sunfish. Ecol. Monogr. 32: 31–78.Google Scholar
  5. Hall, D. J. & E. E. Werner, 1977. Seasonal distribution and abundance of fishes in the littoral zone of a Michigan lake. Trans. am. Fish. Soc. 106: 545–555.Google Scholar
  6. Keast, A., 1977. Mechanisms expanding niche width and minimizing intraspecific competition in two centrarchid fishes. In Hecht, M. K., W. C. Steere & B. Wallace (eds), Evolutionary Biology, Plenum Press, New York, 10: 333–395.Google Scholar
  7. Keast, A., 1978a. Trophic and spatial interrelationships in the fish species of an Ontario temperate lake. Envir. Biol. Fishes 3: 7–31.Google Scholar
  8. Keast, A., 1978b. Feeding interrelations between age groups of pumpkinseed sunfish (Lepomis gibbosus) and comparisons with the bluegill sunfish (L. macrochirus). J. Fish. Res. Bd Can. 35: 12–27.Google Scholar
  9. Lincoln, R. J., G. A. Boxshall & P. F. Clark, 1982. A dictionary of ecology, evolution and systematics. Cambridge University press, Cambridge, 298 pp.Google Scholar
  10. McDowall, R. M., 1968a. Interactions of the native and alien faunas of New Zealand and the problem of fish introductions. Trans. am. Fish. Soc. 97: 1–11.Google Scholar
  11. McDowall, R. M., 1968b. The proposed introduction of the largemous black bass Micropterus salmoides (Lacepède) into New Zealand. N. Z. J. mar. Freshwat. Res. 2: 149–161.Google Scholar
  12. McDowall, R. M., 1984. Exotic fishes — the New Zealand experience. In Courteny, W. R. & J. R. Stauffer (eds), Distribution, Biology and Management of Exotic Fishes. John Hopkins University Press, Baltimor: 200–214.Google Scholar
  13. Mittelbach, G. G., 1981. Foraging efficiency and body size: a study of optimal diet and habitat use by bluegills. Ecology 62: 1370–1386.Google Scholar
  14. Mittelbach, G. G., 1984. Predation and resource partitioning in two sunfishes (Centrarchidae). Ecology 65: 499–513.Google Scholar
  15. Myers, G. S., 1965. Gambusia, the fish destroyer. Aust. Zool. 13: 102.Google Scholar
  16. Nakai, Z., 1962. Apparatus for collecting macroplankton in the spawning surveys of Iwashi (sardine, anchovy, and round herring and others). Bull. Tokai Reg. Fish. Res. Lab. 9: 221–237.Google Scholar
  17. Sarker, A. L., 1977. Feeding ecology of the bluegill, Lepomis macrochirus, in two heated reservoirs of Texas. III- Time of day and patterns of feeding. Trans. am. Fish. Soc. 106: 596–601.Google Scholar
  18. Schramm, H. L., Jr. & K. J. Kirka, 1989. Epiphytic macroinvertebrates as a food resource for bluegills in Florida lakes. Trans. am. Fish. Soc. 118: 416–426.Google Scholar
  19. Terashima, A., 1980. Bluegill — vacant niche remained also in Lake Biwa. In T. Kawai, H. Kawanabe & N. Mizuno (eds), Japanese Freshwater Organisms — Ecology of Invasion and Disturbance. Tokai University Press, Tokyo: 63–70.Google Scholar
  20. Werner, E. E., 1977. Species packing and niche complementarity in three sunfishes. Am. Nat. 111: 553–578.Google Scholar
  21. Werner, E. E. & D. J. Hall, 1974. Optimal foraging and the size selection of prey by the bluegill sunfish (Lepomis macrochirus). Ecology 55: 1042–1052.Google Scholar
  22. Werner, E. E. & D. J. Hall, 1977. Competition and habitat shift in two sunfishes (Centrarchidae). Ecology 58: 869–876.Google Scholar
  23. Werner, E. E. & D. J. Hall, 1979. Foraging efficiency and habitat switching in competing sunfishes. Ecology 60: 256–264.Google Scholar
  24. Werner, E. E. & D. J. Hall, 1988. Ontogenetic habitat shifts in bluegill: the foraging rate — predation risk trade-off. Ecology 69: 1352–1366.Google Scholar
  25. Werner, E. E., J. F. Gilliam, D. J. Hall & G. G. Mittelbach, 1983a. An experimental test of the effects of predation risk on habitat use in fish. Ecology 64: 1540–1548.Google Scholar
  26. Werner, E. E., G. G. Mittelbach, D. J. Hall & J. F. Gilliam, 1983b. Experimental tests of optimal habitat use in fish: the role of relative habitat profitability. Ecology 64: 1525–1539.Google Scholar

Copyright information

© Kluwer Academic Publishers 1992

Authors and Affiliations

  • M. Azuma
    • 1
  1. 1.Biological Laboratory, Faculty of EducationNagasaki UniversityNagasakiJapan

Personalised recommendations