Conservation recommendations for Nee Soon 
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Faunal diversity and conservation 
Diversity and abundance changes of the freshwater fish and decapod fauna of the 
freshwater swamp forest were investigated with the aim of facilitating future 
conservation actions. Surveys were carried out by hand sampling and trap sampling 
from February 2013 to May 2014 in 12 sites that represent different microhabitats 
from the outskirts to the lower, middle, and upper reaches of the streams draining the 
catchment. Stream water parameters (temperature, pH, DO, TDS, etc.) and stream 
profile characters (substrates, cross section, canopy cover, and riparian vegetation) 
were recorded (Cai et al., 2016; Li et al., 2016). Together with the aquatic survey, 
visual-encounter surveys were conducted for terrestrial snails on each side of the stream 
banks. The air humidity and temperature were also recorded at each site. Biodiversity 
baselines were also established for dragonflies of Nee Soon freshwater swamp forest 
based on quantitative sampling across the eight sub-catchments. Hydrological, 
physiochemical parameters and habitats were analysed to identify the main drivers 
structuring the dragonfly community (Cai et al., 2018). 
Species diversity and abundance 
Thirty-three species of native freshwater fish and 9 species of decapod crustaceans 
(5 shrimps and 4 crabs) have been documented in detail. Analysis of the species 
diversity at individual sites showed that one of the sites in the middle of Nee Soon 
freshwater swamp forest supported the highest diversity and richness of native 
freshwater fish and decapods. This site has a deep open pond with slow water flow 
and is directly connected to the forest boundaries at both ends by shallow streams. The 
sandy substrate, uneven stream bed flanked with large patches of aquatic vegetation 
and leaf litter contained a variety of microhabitats stratified for different species of 
fish and crustaceans, which could account for the high species diversity. Sites at the 
outskirts of Nee Soon freshwater swamp forest supported the highest species diversity 
of introduced fish and shrimp. The periodic release of water from the Upper Seletar 
Reservoir might have contributed to the high species diversity of introduced fish and 
shrimp. The four most abundant native species of fish found in Nee Soon freshwater 
swamp forest were Trigonostigma heteromorpha, Hemirhamphodon pogonognathus, 
Rasbora elegans and Betta pugnax, and the most abundant species of shrimp and crab 
are Macrobrachium malayanum and Parathelphusa maculata respectively (Cai et al., 
2016; Li et al. 2016). A total of 10 families, 18 genera and 19 species of land snails 
were recorded from the Nee Soon freshwater swamp forest. The outskirts had the 
highest species diversity, while the Upper Swamp had the lowest species diversity. 
The three most abundant species found in Nee Soon freshwater swamp forest are 
Liardetia convexoconica, Helicarion perfragilis and Hemiplecta humphreysiana (Lim 
et al., 2018). Fourty-nine species of odonates, belonging to 34 genera in 11 families 
were recorded in the current study. An updated species list of Nee Soon dragonflies is 
provided for future reference, with 67 species belonging to 47 genera in 11 families, 
representing about half of all odonates ever recorded in Singapore. Among the eight 
sub-catchments, the three mid sub-catchments all show low abundance and species 
richness. This is followed by the two upper sub-catchments. The three low sub- 
