Records of terrestrial and mangrove snails (Mollusca: Gastrop..

During a brief malacological survey, a total of 16 snail species were recorded (four mangrove amphibious, 12 terrestrial). For all the species new localities with GPS coordinates and habitat data are provided. The species Thapsia insulsa Preston, 1910 (Urocyclidae) is a new record to the island.


Introduction
Unguja, the main island of the Zanzibar Archipelago, lies about 6°south of the equator and 40 km east of the mainland of Africa and has an area of approximately 1600 km 2 (Pakenham, 1984). Most of the island is covered by high and low scrub forest, also known as a coral rag forest on ground characterised by numerous outcroppings of fossilised coral (Siex, 2011). This vegetation cover is classified as Eastern African Coastal Scrub Forest according to the Clarke's scheme (Burgess & Clarke, 2000).
The East African coastal land mollusc fauna remains poorly explored (Verdcourt, 2006). The territory of Zanzibar autonomous region (Republic of Tanzania) is one of the best studied in terms of species composition of land snails (Rowson, 2007;Rowson et al., 2010;Gittenberger & Bruggen, 2013) but many species have been reported without exact localities or they are problematic to find considering their names (Rowson, 2007). In this short note, I report of some exact species localities at the poorly known Michamwi Peninsula of the Unguja Island and one new record to the island malacofauna.

Material and methods
The study was carried out during the period 27.2.2021 -6.3.2021. A few closely situated localities were surveyed at the northernmost area of the Michamwi Peninsula, east coast of the Unguja Island (Michamwi is situated on the opposite side of the Chwaka Bay from the Jozani Forest). The specimens (dry shells) were collected by hand or by sieving of soil and detritus. Species names are following Rowson (2007) and Gittenberger & Bruggen (2013).

Results and discussion
There were a total of 16 snail species recorded (four mangrove amphibious, 12 terrestrial). One of the terrestrial species is a new record to the fauna of the Un- Material examined: 27.2.2021, mangrove dominated by Avicennia marina at a river estuary, south of the Michamwi Village, S06°08' 45.5" E39°29' 22.9", 5 m a.s.l., 1 shell and many living individuals observed (Fig. 1b); 2.3.2021, among rocks and various bushes at the periphery of the tidal zone, north-west coast of the peninsula, S06°07' 39.4" E39°29' 28.2", 2 m a.s.l., many living individuals observed. This species is widespread in the mangroves of the tropics (Abbott & Dance, 2000). In East Africa, it is rare in the coastal area of the continent but abundant on the nearby Pemba Island (Torres et al., 2008). Michamwi Village, S06°08' 45.5" E39°29' 22.9", 5 m a.s.l., 5 shells and many living individuals observed (Fig. 1c). Common estuarine species in the Indo-Pacific Region (Abbott & Dance, 2000).
Achatina (Lissachatina) reticulata (L. Pfeiffer, 1845) Material examined: 27.02 -6.3.2021, Michamwi Village area, many shells observed (often broken and at fire sites with traces of possible human consumption or other use). Native to East Africa, mainly coastal species reported from many localities on the Unguja Island (Bequaert, 1950;Rowson, 2007).

Ariophantidae
Sitala jenynsi (L. Pfeiffer, 1845) Material examined: 4.3.2021, Michamwi Village area, scattered bushes and trees on a sandy terrain, under rocks of a limestone hill, S06°08' 17.5" E39°29' 38.8", 5 m a.s.l., 8 shells, and many more observed at the area. Lowland coastal species, known from Kenya, Tanzania and Mozambique and some closely situated islands (Verdcourt, 1963). From the Unguja island it was reported with an exact locality only by Rowson (2007) at the Jozani Forest.