There are approximately 24,000 described land snail species worldwide and it has been estimated that there are probably 11,000 to 40,000 undescribed species (Lydeard et al., 2004). Terrestrial mollusc species tend to have very small ranges, sensitive to changes associated with human disturbance, and are prone to extinction by habitat destruction (Schilthuizen et al., 2005; Douglas et al., 2013). Thus, land snails can be used as environmental indicators (Nurinsiyah et al., 2016). It has been estimated that already 7% of the land snails became extinct (Régnier et al., 2015).
In Java, 209 land snail species are known. Among them, 69 species and 17 subspecies are endemic to Java, and 12 are introduced species (van Benthem Jutting, 1948, 1950, 1952; Loosjes, 1953; Butot, 1955; de Winter, 1983, 1998; Dharma, 1992, 2007; Whitten et al., 1997; Vermeulen and Whitten, 1998; Heryanto, 2011; Nurinsiyah, 2015; Nurinsiyah et al., 2016).
Most land snails play an important role in the ecosystem as detritivores. Some are carnivorous like the Streptaxidae, which are represented on Java only by an introduced species, Gulella bicolor (Hutton, 1834).
Our survey in the Halimun-Salak National Park in 2015 resulted in 44 land snail species, of which 21 were first records for the park. Additional 23 land snail species have been previously recorded in Halimun-Salak National Park (Heryanto et al., 2003). One of the species discovered by our survey proved to be new to science.