Coral Reefs

, Volume 3, Issue 1, pp 43–50 | Cite as

The molluscan fauna of Chagos (Indian Ocean) and an analysis of its broad distribution patterns

  • Anne L. S. Sheppard


A detailed survey of molluscs in the Chagos Archipelago was made (1) to determine whether this isolated atoll group has a diverse fauna, and (2) to identify broad-scale distribution patterns of molluscs in relation to depth, exposure and substrate type: 384 confirmed species (including 282 gastropods and 99 bivalves) compares with reported diversities from other island and continental reef areas, suggesting that Chagos is not depauperate. Molluscs were sampled from 18 zones, which encompassed all habitats to 40 m deep. Cluster analysis based on species similarity revealed 4 main groups from hard substrate and 1 from soft substrate. On hard substrate, depth or depth-related parameters were a stronger determinant of molluscan distribution than seaward or lagoonal position, and greatest diversity occurred between 10–20 m deep on reefs of all exposures.


Distribution Pattern Indian Ocean Bivalve Sedimentology Atoll 
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  1. Abbott RT (1950) The molluscan fauna of the Cocos-Keeling island, Indian Ocean. Bull Raffles Mus 22:68–98Google Scholar
  2. Burr EJ (1970) Cluster sorting with mixed characters. II. Fusion strategies. Aust Comp J 2:98–103Google Scholar
  3. Goreau TF, Goreau NI, Goreau TJ (1979) Corals and coral reefs. Sci Am 241:110–121Google Scholar
  4. Kay A (1971) The littoral marine molluscs of Fanning Island. Pac Sci 25:260–281Google Scholar
  5. Kay A, Switzer MF (1974) Molluscan distribution patterns in Fanning Island lagoon and a comparison of the molluscs of the lagoon and seaward reefs. Pac Sci 28:275–295Google Scholar
  6. Kohn AJ (1959) The ecology of Conus in Hawaii. Ecol Monogr 29:47–90Google Scholar
  7. Kohn AJ (1978) The Conidae (Mollusca: Gastropoda) of India. J Nat Hist 12:295–335Google Scholar
  8. Kohn AJ, Robertson R (1966) The Conidae (Gastropoda) of the Maldive and Chagos Archipelagoes. J Mar Biol Assoc India 8:273–277Google Scholar
  9. Lienard E (1877) Catalogue de la fauna malacologique de l'ile Maurice et ses dependances. Bull Soc Hist Nat d'Atun IV:1–115Google Scholar
  10. Maes VO (1967) The littoral marine molluscs of Cocos-Keeling islands (Indian Ocean). Proc Acad Nat Sci Philadelphia 119:93–165Google Scholar
  11. Mastaller M (1978) The marine molluscan assemblages of Port Sudan, Red Sea. Zool Meded 53:117–144Google Scholar
  12. Melville JC (1909) Report on the marine mollusca obtained by Mr J Stanly Gardiner FRS among the islands of the Indian Ocean in 1905. Trans Linn Soc London II, Zool 13:65–138Google Scholar
  13. Poisson H (1953) Contribution a l'etude de la fauna malacologique marine de l'Archipel des Chagos et de l'ile d'Agalega. Bull Acad Malgache 31:63–70Google Scholar
  14. Purvis I (1973) Unpublished manuscript of work done on Joint Services Expedition to Egmont Atoll, Chagos ArchipelagoGoogle Scholar
  15. Salvat B (1972) Distribution des mollusques sur les recifs exterieurs de l'atoll de Fangataufa (Tuamotu, Polynesie) radiales quantitatives. Proc Symp Corals and Coral Reefs, 1969, pp 373–378Google Scholar
  16. Sheppard CRC (1980) Coral cover, zonation and diversity on reef slopes of Chagos atolls, and population structures of the major species. Mar Ecol Prog Ser 2:193–205Google Scholar
  17. Sheppard CRC (1981a) The groove and spur structures of Chagos atolls and their coral zonation. Estuarine Coastal Shelf Sci 12:549–560Google Scholar
  18. Sheppard CRC (1981b) The reef and soft substrate coral fauna of Chagos, Indian Ocean. J Nat Hist 15:607–621Google Scholar
  19. Sheppard CRC (1982) Coral populations on reef slopes and their major controls. Mar Ecol Prog Ser 7:93–115Google Scholar
  20. Stoddart DR (1969) Ecology and morphology of recent coral reefs. Biol Rev 44:433–498Google Scholar
  21. Taylor JD (1968) Coral reefs and associated invertebrate communities (mainly molluscan) around Mahe, Seychelles. Phil Trans Soc London Ser B 254:129–206Google Scholar
  22. Taylor JD (1970) Intertidal zonation at Aldabra atoll. Phil Trans Soc London Ser B 260:173–213Google Scholar
  23. Taylor JD (1971a) Marine mollusca from Diego Garcia. Atoll Res Bull 149:105–125Google Scholar
  24. Taylor JD (1971b) Reef associated molluscan assemblages in the western Indian Ocean. Symp Zool Soc London 28:501–534Google Scholar
  25. Thomassin BA, Ganelon P (1977) Molluscan assemblages on the boulder tracts of Tulear coral reefs (Madagascar). Proc 3rd Int Coral Reef Symp 1:247–252Google Scholar
  26. Ward JH (1963) Hierarchical grouping to optimise an objective function. J Am Stat Assoc 58:236–246Google Scholar
  27. Wells JW (1957) Coral reefs. Geol Soc Am Mem 67:609–631Google Scholar

Copyright information

© Springer-Verlag 1984

Authors and Affiliations

  • Anne L. S. Sheppard
    • 1
  1. 1.Australian Institute of Marine ScienceTownsville M.S.O.Australia

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