Seychelles biodiversity
The Republic of Seychelles comprises 115 islands located within the Madagascar region biodiversity hotspot. Levels of biodiversity are known to be high, with the most recent overview estimating the presence of 850 plants and 2,426 insect species, although noting that for at least some islands insect diversity may be 3 times higher than the available estimates. These estimates were largely based on collections made on 32 islands by the Percy Sladen Trust Expeditions of 1905 and 1908-9. In 2000 the Indian Ocean Biodiversity Assessment 2000-2005 (IOBA) was initiated to complete and update the collections made by the Percy Sladen Trust Expedition 100 years earlier. This resulted in extensive collections of all multicellular terrestrial and freshwater taxa throughout the islands, placing the diversity of the islands at 5,381 species (1,139 plants, 12 algae, 70 fungi, 250 lichens, 3,775 invertebrates, 135 vertebrates).
| Taxon | Number of species | |
| Plants | Bryophyta | 200 |
| Pteridophyta | 85 | |
| Angiospermae | 854 | |
| Algae | 12 | |
| Fungi & lichens | 320 | |
| Animals | Platyhelminthes | 7 |
| Annelida | 16 | |
| Nemertea | 1 | |
| Nematoda | 50 | |
| Rotifera | 15 | |
| Mollusca | 75 | |
| Tardigrada | 34 | |
| Insecta | 3067 | |
| Crustacea | 77 | |
| Myriapoda | 71 | |
| Chelicerata | 362 | |
| Vertebrata | 135 |
More details are given on some groups of species on the following pages:
