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Ecological Research

, Volume 19, Issue 5, pp 475–483 | Cite as

Factors affecting Sarcocystis infection of rats on small tropical islands

  • Ilan PAPERNA
  • Kelvin S.-H. PEH
  • Paolo MARTELLI
  • Lian Pin KOH
  • Navjot S. SODHI
Original Articles

The purpose of our research was to explore the limits of rat-python-Sarcocystis distribution among rats on the offshore tropical islands of Singapore, and to examine the effect of island size, insular isolation, landscape peculiarities and anthropogenic disturbance. Commensal rats (Rattus rattus) inhabited all of these islands, regardless of the island’s size, proximity to the mainland, biogeographic features, and/or degree of anthropogenic interference. Rats caught on Sakijang Pelepah Island had well deliminated white bellies that are similar to those of sylvatic or feral rats. The prevalence of Sarcocystis spp. on individual islands ranged from 57 to 100%. This is consistent with the range found in forested habitats on Singapore Island. It also exhibited a similar diversity to Sarcocystis spp. and the predominance of Sarcocystis singaporensis. On Sakijang Pelepah Island, one rat (white bellied) was exceptionally heavily infected with both Sarcocystis villivilosi and Sarcocystis sulawesiensis. The muscles of the rats from nearly all of the islands contained immature sarcocysts, which implies that active transmission is taking place on these islands. This suggests that reticulated pythons (Python reticulatus), which are the definitive hosts of rat Sarcocystis, might have been established or frequented in all the islands of Singapore. Our study shows that the Sarcocystis infection load of the rats was negatively correlated with human disturbance, hinting that human disturbance restricts the pythons’ mobility and thus, reduces infection of Sarcocytis in the islands rats.

Key words

offshore islands Rattus rattus, Sarcocystis spp. Singapore 

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References

  1. Beaver P. C. & Maleckar J. R. (1981) Sarcocystis singaporensis Zaman and Colley 1975, 1976, Sarcocystis villivilosi sp. nov. & Sacocystis zamani sp.n. Development, morphology and persistence in the laboratory rat, Rattus norvegicus. Journal of Parasitology 67: 241–246.Google Scholar
  2. Häfner U. & Frank W. (1984) Host specificity and host range of the genus Sarcocystis in three snake-rodent life cycles. Zentralblatt für Bakteriologie, Microbiologie und Hygiene. Original A 256: 296–299.Google Scholar
  3. Jäkel T., Khoprasert Y., Sorger I., Kliemt D., Seehabutr V., Suasa-ard K. & Hongnark S. (1997) Sarcosporidiasis in rodents from Thailand. Journal of Wildlife Diseases 33: 860–867.Google Scholar
  4. Koh L. P., Sodhi N. S., Tan H. T. W. & Peh K. S.-H. (2002) Factors affecting the distribution of vascular plants, springtails, butterflies and birds on small tropical islands. Journal of Biogeography 29: 93–108.Google Scholar
  5. Munday B. L. & Mason R. W. (1980) Sarcocystis and related organisms in Australian wildlife III. Sarcocystis murinothechis sp. n., life cycle in rats (Rattus, Pseudomys and Mastomys spp.) and tiger snakes (Notechis ater). Journal of Wildlife Diseases 16: 83–87.Google Scholar
  6. O’Donoghue P. J., Watts C. H. & Dixon B. R. (1967) Ultrastructure of Sarcocystis spp. (Protozoa: Apicomplexa) in rodents from north Sulawesi and west Java, Indonesia. Journal of Wildlife Diseases 23: 225–232.Google Scholar
  7. Paperna I. & Martelli P. (2001) Sarcocystis in rats and pythons on Singapore island. In: Advances in Vertebrate Pest Management II (eds H. J. Pelz, D. P. Cowan & C. J. Feare), pp. 373–380. Filander Verlag, Furth, Germany.Google Scholar
  8. Parent C. & Weatherhead P. J. (2000) Behavioral and life history responses of eastern massasauga rattlesnakes (Sistrurus catenatus catenatus) to human disturbance. Oecologia 125: 170–178.Google Scholar
  9. Schwartz E. & Schwartz H. E. (1965) A monograph of the Rattus rattus group. Annales de la Escuela Nacional de Ciencas Biologicas México 14: 79–178.Google Scholar
  10. Zaman V. & Colley F. C. (1975) Light and electron microscopic observations on the life cycle of Sarcocystis orientalis sp. nov.in the rat (Rattus norvegicus) and the Malaysian reticulated python (Python reticulatus). Zeitschrift für Parasitenkunde 47: 169–185.Google Scholar

Copyright information

© Blackwell Publishing Ltd 2004

Authors and Affiliations

  • Ilan PAPERNA
    • 1
  • Kelvin S.-H. PEH
    • 2
    • 3
  • Paolo MARTELLI
    • 4
  • Lian Pin KOH
    • 3
  • Navjot S. SODHI
    • 3
  1. 1.Department of Animal Science, Faculty of Agriculture, Food and Environmental QualityHebrew University of JerusalemIsrael
  2. 2.Swedish Biodiversity CenterUppsalaSweden
  3. 3.Department of Biological SciencesNational University of SingaporeSingaporeRepublic of Singapore
  4. 4.Singapore Zoological Gardens Veterinary ClinicSingaporeRepublic of Singapore

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