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drainage (Fig. 13). Of the three groups recorded, Palaemonidae was the most common 
throughout the Nee Soon drainage (recorded at 32 sites), while the Brachyura (recorded 
at 18 sites), as well as the Atyidae (recorded at 13 sites), were mostly recorded at the 
southwest of the drainage (co-recorded at sites 1 to 13) (Table 2). In total, decapods 
were found in 34 sites in the Nee Soon drainage, with the most abundant site (site 32) 
having 73 Palaemonidae individuals. 
Class OSTRACODA 
The tiny Ostracoda, or seed shrimps, are small crustaceans which are found in 
freshwater and marine environments worldwide. They can be either free-swimming or 
benthos-dwellers. Ostracods possess a carapace made out of a hinged valve or shell, 
somewhat resembling that of a bivalve, which protects them from predation. In some 
species, the carapace is ornamented with spikes or protrusions, while others have a 
smooth, featureless carapace (Yule & Yong, 2004). They have a wide dietary range, 
with some being predators, while others are scavengers or filter feeders (Ng et al., 
2011 ). 
In the Nee Soon drainage, ostracods were found at three sites in the northeast 
areas in large numbers (the highest number of individuals recorded was 225 at site 32) 
(Fig. 14). They were almost completely absent from the rest of the swamp forest. 
Class ENTOGNATHA 
The Entognatha were previously classified as insects, but have recently been separated 
and placed into their own class. They are wingless, six-legged arthropods which possess 
mouthparts recessed into the head, with only the tips of the mandibles and maxilla 
exposed. The subclass Collembola are perhaps the best known of the Entognatha, 
and are commonly called the springtails, due to their possession of a two-pronged 
appendage known as the furcula (Yule & Yong, 2004). This organ is usually found 
under the abdomen and is held under tension most of the time. When the springtail is 
alarmed, it releases the furcular, which then impacts against the substrate and propels 
the springtail into the air, away from the source of the alarm. 
Subclass Collembola 
In the Nee Soon freshwater swamp forest, Collembola are not very common, and were 
found in several scattered locations throughout the entire drainage. They were only 
found in 10 sites, with the most abundant site (site 24), only recording a total of four 
individuals (Fig. 15). 
