Aquatic macroinvertebrates of Nee Soon 
95 
Fig. 14. Distribution and abundance of class Ostracoda in the Nee Soon drainage. Solid 
circles indicate sites where representatives were collected and circle sizes are proportionate to 
abundance/numbers of individuals captured as reflected in the accompanying legend. 
Class GASTROPODA 
The gastropods are a group of molluscs possessing a large, fleshy organ known as 
a foot, which is used to move around. They are commonly referred to as snails or 
slugs, depending on whether they possess a shell or not. The gastropods are found 
in terrestrial, freshwater and marine environments worldwide. Many gastropods are 
hermaphrodites. While most feed on plant matter or are scavengers, some gastropods 
are predators instead (Ng et al., 2011). Terrestrial snails and slugs from the Nee Soon 
freshwater swamp forest have been surveyed by Lim et al. (2018). 
