Predator-Prey Role Reversal in a Marine Benthic Ecosystem

Two closely located islands on the west coast of South Africa support widely different benthic communities. The biota at Malgas Island is dominated by seaweeds and by rock lobsters that consume settling mussels, thereby preventing the establishment of the mussels. They also prey on whelks, although one speces, Burnupena papyracea, is protected from predation by a commensal bryozoan that covers its shell. Marcus Island has extensive mussel beds, but rock lobsters and seaweeds are virtually absent; whelks (mostly Burnupena spp.) occur at high densities. Rock lobsters transferred to Marcus Island were overwhelmed and consumed by the whelks, reversing the normal predatorprey relation between the two species. These two contrasting communities persisted during 4 years and may represent multiple states of the same ecosystem. This effective change of roles between a prey species and its chief predator may provide an intrinsic mechanism to maintain these states following the initial exclusion of the predator.

[1]  J. Connell,et al.  Further Comments on the Evidence for Multiple Stable Points in Natural Communities , 1985, The American Naturalist.

[2]  L. Slobodkin,et al.  Community Structure, Population Control, and Competition , 1960, The American Naturalist.

[3]  A. Whittick.  Spatial and temporal distributions of dominant epiphytes on the stipes of Laminaria hyperborea (Gunn.) Fosl. (Phaeophyta: Laminariales) in S.E. Scotland , 1983 .

[4]  J. Connell,et al.  On the Evidence Needed to Judge Ecological Stability or Persistence , 1983, The American Naturalist.

[5]  P. Fairweather,et al.  Preliminary investigations of predation by the whelk Morula marginalba , 1984 .

[6]  J. Sutherland,et al.  Multiple Stable Points in Natural Communities , 1974, The American Naturalist.

[7]  A. Penney,et al.  Prey selection and the impact of the starfish Marthasterias glacialis (L.) and other predators on the mussel Choromytilus Meridionalis (Krauss) , 1984 .

[8]  J. Estes,et al.  Aleuts, Sea Otters, and Alternate Stable-State Communities , 1978, Science.

[9]  T. Croll,et al.  Fusion and gemination in one dental arch: report of case. , 1981, ASDC journal of dentistry for children.

[10]  B. Shorrocks,et al.  Animal Populations in Relation to Their Food Resources. , 1971 .

[11]  C. Christophersen,et al.  Dogger Bank itch. The allergen is (2-hydroxyethyl)dimethylsulfoxonium ion , 1980 .

[12]  G. Caughley.  ERUPTION OF UNGULATE POPULATIONS, WITH EMPHASIS ON HIMALAYAN THAR IN NEW ZEALAND , 1970 .

[13]  S. Levings,et al.  Homing to scars as a defense against predators in the pulmonate limpet Siphonaria gigas (Gastropoda) , 1983 .

[14]  Tim Gerrodette,et al.  Patch Dynamics and Stability of Some California Kelp Communities , 1984 .

[15]  P. Dayton.  The Structure and Regulation of Some South American Kelp Communities , 1985 .

[16]  E. Knight-Jones,et al.  Anti-fouling role of antibiotics produced by marine algae and bryozoans , 1977, Nature.