An Assessment of the Status of Biodiversity in the ... - IUCN

from these mammals, a few species of insectivorous bats (micro-chiroptera) and shrews werefrequently observed.Species composition and relative abundance of selected invertebrate faunaOnly two groups of invertebrates - butterflies and molluscs were surveyed and the number ofspecies recorded is presented in Table 5. Approximately 20% of the butterfly species of SriLanka were recorded from Maduganga (Appendix 8). These ranged from the small lycaenidspecies to the large swallowtail species. However, not a single endemic butterfly species wasobserved. About 10% of the butterfly species in Maduganga are threatened.The molluscs recorded include 14 land snails (Appendix 9) and 11 brackish water species(Appendix 10). Approximately 60% of the land snails in Maduganga (mainland and islands)are endemic and threatened as well. Among the land snail species, two are invasive alienspecies (Giant African Snail - Achatina fulica and Slug - Laevicaulis alte). The endemicGlessula paneantha is a highly threatened land snail. In addition, the endemic Acavushaemastoma - a relict species that depicts Gondwanaland fauna is also present in some of theislands and mainland areas of Maduganga. The most common molluscs in mangrove habitatsincluded Telescopium telescopium, Cerithedia cingulata, and Nerita polita.The most common crustacean species recorded in the Maduganga estuary include the MudCrab (Scylla serrata), Grapsid Crabs (Chiromantes spp.), the Mud Lobster (Thalassinaanomala) and the White Prawn (Penaeus indicus).Table 5A comparison of butterflies and molluscs in Sri Lanka and MadugangaGroup Sri Lanka MadugangaButterflies 243 (20E, 76T) 50 (5T)Terrestrial molluscs 235 (198E, 116T) 14 (8E,8T)Aquatic molluscs (Brackish Water) Unknown 11E - Endemic, T - Threatened (IUCN Sri Lanka, 2000).13