Cannibalism (Zoology) Information
In zoology, cannibalism is the act of one individual of a species consuming all or part of another individual of the same species as food. Cannibalism is a common ecological interaction in the animal kingdom and has been recorded for more than 1500 species [1] It does not, as once believed, occur only as a result of extreme food shortages or artificial conditions, but commonly occurs under natural conditions in a variety of species.[1][2][3] Cannibalism seems to be especially prevalent in aquatic communities, in which up to approximately 90% of the organisms engage in cannibalism at some point of the life cycle. Cannibalism is also not restricted to carnivorous species, but is commonly found in herbivores and detritivores.[2]
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Sexual cannibalism
Main article: Sexual cannibalismSexual cannibalism is a special case of cannibalism in which a female organism kills and consumes a conspecific (same species) male before, during, or after copulation. Rarely, these roles are reversed.[4][5] Sexual cannibalism has been recorded in the female redback spider, black widow spider, praying mantis, and scorpion, among others.
Size-structured cannibalism
Nematode Mononchidae eating another Mononchidae.Size-structured cannibalism, in which large individuals consume smaller conspecifics, is more common. In such size-structured populations, cannibalism can be responsible for 8% (Belding's Ground Squirrel) to 95% (dragonfly larvae) of the total mortality,[6] making it a significant and important factor for population[7] and community dynamics.[8] Such size structured cannibalism has commonly been observed in the wild for a variety of taxa.
Cannibalistic infanticide
Further information: Infanticide (zoology)Another common form of cannibalism is filial cannibalism (a form of infanticide) where adults eat the young of their own species (sometimes even their own immediate offspring). Classical vertebrate examples include chimpanzees, where groups of adult males have been observed to attack and consume conspecific infants,[9][10][11] and cats.[12] In agricultural settings, pigs are known to eat their own young, accounting for a sizeable percentage of total piglet deaths.
Particularly in fish, one can discern
- total filial cannibalism, where a parent eats the whole brood
- cases where a parent eats only part, e.g. sand gobies Potamoschistus minutus can eat 40% of their eggs without reducing the outcome of their reproductive efforts.[13]
Intrauterine cannibalism
Main article: OophagyIntrauterine cannibalism is a behaviour in some carnivorous species, in which multiple embryos are created at impregnation, but only one or two are born. The larger or stronger ones consume their less-developed siblings as a source of nutrients.
In adelphophagy, the fetus eats sibling embryos, while in oophagy it feeds on eggs.[14][15] Human adelphophagy has been suspected in at least one case, most recently on 23 November 1983. In this well-documented incident, a female child "Rebecca" was born in California with tufts of hair remaining in her mouth, presumably belonging to a consumed twin. (Citation Needed)
Intrauterine cannibalism is known to occur in lamnoid sharks[16] and in the Fire Salamander,[17] as well as in some teleost fishes.[15] The Carboniferous period chimaera, Delphyodontos dacriformes, is suspected of having practiced intrauterine cannibalism, also, due to the sharp teeth of the recently born (or possibly aborted) juveniles (adults are unknown), and the presence of fecal matter in the juveniles' guts.[18]
References
- ^ a b G. A. Polis, The evolution and dynamics of intraspecific predation. Annual Review of Ecology and Systematics 12, 225-251 (1981).
- ^ a b Laurel R. Fox, Cannibalism in natural populations. Annual Review of Ecology and Systematics 6, 87-106 (1975).
- ^ M. A. Elgar and B. J. (eds) Crespi, Cannibalism: Ecology and evolution among diverse taxa. (Oxford University Press, New York, 1992).
- ^ Kenwyn Blake Suttle (1999). "The Evolution of Sexual Cannibalism". University of California, Berkeley. http://ib.berkeley.edu/courses/ib160/past_papers/suttle.html.
- ^ Min-Li Tsai & Chang-Feng Dai (2003). "Cannibalism within mating pairs of the parasitic isopod Ichthyoxenus fushanensis" (abstract page). Journal of Crustacean Biology 23 (3): 662–668. doi:10.1651/C-2343. http://www.bioone.org/perlserv/?request=get-abstract&issn=0278-0372&volume=023&issue=03&page=0662.
- ^ G. A. Polis, The evolution and dynamics of intraspecific predation. Annual Review of Ecology and Systematics 12, 225-251 (1981)
- ^ David Claessen, A. M. De Roos, and L. Persson, Population dynamic theory of size-dependent cannibalism. Proceedings of the Royal Society of London Series B-Biological Sciences 271 (1537), 333-340 (2004)
- ^ V. H. W. Rudolf, Consequences of stage-structured predators: Cannibalism, behavioral effects and trophic cascades. Ecology 88, 2991-3003 (2007)
- ^ A. C. Arcadi and R. W. Wrangham, Infanticide in chimpanzees: Review of cases and a new within-group observation from the Kanyawara study group in Kibale National Park. Primates 40 (2), 337-351 (1999).
- ^ M. L. Wilson, W. R. Wallauer, and A. E. Pusey, New cases of intergroup violence among chimpanzees in Gombe National Park, Tanzania. International Journal Of Primatology 25 (3), 523-549 (2004).
- ^ D. P. Watts, J. C. Mitani, and H. M. Sherrow, New cases of inter-community infanticide by male chimpanzees at Ngogo, Kibale National Park, Uganda. Primates 43 (4), 263-270 (2002)
- ^ Hartwell, S, Cats that kill kittens
- ^ Bioone Online Journals - Parents Benefit From Eating Offspring: Density-Dependent Egg Survivorship Compensates For Filial Cannibalism
- ^ Thierry Lodé 2001. Les stratégies de reproduction des animaux (reproduction strategies in animal kingdom). Eds Dunod Sciences, Paris
- ^ a b Crespi, Bernard; Christina Semeniuk (2004). "Parent-Offspring Conflict in the Evolution of Vertebrate Reproductive Mode". The American Naturalist 163 (5): 635–654. doi:10.1086/382734. PMID 15122484.
- ^ Hamlett, William C.; Allison M. Eulitt, Robert L. Jarrell, Matthew A. Kelly (1993). "Uterogestation and placentation in elasmobranchs". Journal of Experimental Zoology 266 (5): 347–367. doi:10.1002/jez.1402660504.
- ^ Stebbins, Robert C.; Nathan W. Cohen (1995). A Natural History of Amphibians. Princeton, NJ: Princeton University Press. p. 9. ISBN 0-69110-251-1.
- ^ Lund, R. 1980. Viviparity and intrauterine feeding in a new holocephalan fish from the Lower Carboniferous of Montana. Science, 209: 697‑699.
Further reading
| Wikimedia Commons has media related to: Animal cannibalism |
- M. A. Elgar and Bernard J. Crespi (eds.). 1992. Cannibalism: Ecology and Evolution of Cannibalism among Diverse Taxa Oxford University Press, New York. (361pp) ISBN 0198546505
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Categories: Cannibalism
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