The mechanics of predation by the shore crab, Carcinus maenas (L.), on the edible mussel, Mytilus edulis L.
- 31 December 1977
- journal article
- research article
- Published by Springer Nature in Oecologia
- Vol. 36 (3), 333-344
- https://doi.org/10.1007/bf00348059
Abstract
Mechanical aspects of predation by the shore crab, Carcinus maenas, on the edible mussel, Mytilus edulis, were examined. The shore crabs from the population studied utilized five distinct, largely size-related, mussel-opening techniques. Crushing the mussel umbone appeared the most successful opening method for medium-sized prey. Small mussels were crushed outright and large mussels could be opened by a slow, uneconomical, boring technique. The strengths of mussels, from an exposed shore, were tested under compression in four separate planes to determine the loads a crab would need to apply to crush the shells outright and the mechanical properties of mussels. Little inter-plane variability in compressive strength was observed, although intra-plane variability appeared high. The compressive strengths of mussels from a sheltered shore were found to be significantly higher than those from the exposed shore in the plane tested. A strain gauge was embedded in a mussel shell enabling the pattern and magnitude of forces produced by crab chelae in opening a mussel to be studied. The crab's chelae did not appear overwhelmingly strong when compared directly to the compressive strength of the crab's preferred mussel sizes. It is, therefore, postulated that crabs usually seek out and exploit weak spots in the umbone of mussels by trial and error, eventually breaking through the shell by a cumulative process of extending minute fractures in the shell substructure.Keywords
This publication has 19 references indexed in Scilit:
- Energy Maximization in the Diet of the Shore Crab, Carcinus maenasJournal of Animal Ecology, 1978
- Mechanical properties of mother of pearl in tensionProceedings of the Royal Society of London. B. Biological Sciences, 1977
- Further studies on the mechanical properties of mollusc shell materialJournal of Zoology, 1976
- Leverage and muscle type in crab chelae (Crustacea: Brachyura)Journal of Zoology, 1976
- Experiments on the survival, growth and yield of relaid seed mussels (Mytilus edulis L.) in the Menai Straits, North WalesICES Journal of Marine Science, 1976
- Interoceanic differences in vulnerability of shelled prey to crab predationNature, 1976
- Neuromuscular analysis of closing in the dimorphic claws of the lobster Homarus americanusJournal of Experimental Zoology, 1974
- Structural and contractile properties of lobster leg‐muscle FibersJournal of Experimental Zoology, 1971
- The Ecology of Lough IneJournal of Animal Ecology, 1964
- The Ratio of Shell to Meat in Mytilus as a Function of Tidal Exposure to AirICES Journal of Marine Science, 1957