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Ganl. Bull. Singapore 70 (Suppl. 1) 2018 
Macroinvertebrate communities in forested streams are strongly influenced by debris 
input from riparian vegetation. The lack of canopy cover could result in a community 
that favours taxa with diverse feeding habits that can deal with the allochthonous debris 
(e.g, plecopteran shredders that feed by cutting and tearing large pieces of debris/ 
organic matter) (Schmidt-Kloiber et al., 2006). 
Habitats at the outskirts of the Nee Soon catchment are more exposed to potential 
encroachment of non-native taxa from other catchments. For example, a South 
American cichlid, Acarichthys heckelii, was recently reported for the first time within 
the outskirts of the Nee Soon freshwater swamp forest (Tan & Lim, 2008; Ng & Tan, 
2010). Whilst existing environmental conditions may hinder the establishment of non¬ 
native species, the constant propagule pressure from the reservoir (Yeo & Chia, 2010) 
may pose a future threat (Holle & Simberloff, 2005; Lockwood et al., 2005). The Nee 
Soon streams also drain into the Lower Seletar Reservoir via Sungai Seletar, which 
may be another potential source of non-native taxa, since Lower Seletar Reservoir also 
contains many established populations of non-native species (Ng & Tan, 2010). 
While the present study captured a representation of forest stream fauna across 
the catchment, there is always the possibility that certain groups were not obtained 
in the course of sampling due to limitations in the sampling methods. In the future, 
additional methods such as deployment of colonisers could be utilised in addition to 
traditional kick sampling methods, in order to ensure that a wider range of diversity is 
captured. As the life cycle of numerous insects are associated with different types of 
habitat (e.g. all aquatic dipteran larvae emerge as terrestrial adults), sampling methods 
that capture adult insects can also be useful to supplement the determination of aquatic 
macroinvertebrate diversity. Malaise traps (Gressitt & Gressitt, 1962) are an effective 
means of collecting many types of adult insects, and have been deployed in various 
parts of Singapore (including the Nee Soon freshwater swamp forest) for taxonomic 
work with adult insects (e.g. Grootaert, 2006; Ngiam & Cheong, 2016). Emergence 
traps have also been adapted for use in tropical streams (e.g. in the Philippines) (Freitag, 
2004a, 2004b) and are useful for capturing emerging adults at specific riverine locations. 
Alternative sampling methods for larvae collection include electroshocking techniques 
(Taylor et al., 2001), which use electrofishing equipment to collect and quantitatively 
sample stream invertebrates. Processing of samples collected by electroshocking 
techniques has been reported to be 40% faster than traditional sampling methods, due 
to a reduction of debris collected in the samples (Taylor et al., 2001). 
Unfortunately, knowledge of aquatic macroinvertebrate taxonomy is limited in 
the tropical Asian region. Many of the molluscs and decapods can be identified to 
the species level (Ng, 1988; Ng, 1990; Tan et al., 2012), and some taxonomic groups 
such as the Odonata or the Hemiptera can be identified to the genus level (Yeo, 2012; 
Tran et al., 2015). However, many other groups including the Trichoptera and Diptera 
cannot be identified beyond the family level without the assistance of taxonomic 
experts. This results in a loss of resolution and information about species distribution, 
especially with regards to species of conservation value. Identifying specimens down 
to the genus and the species levels could be achieved in future studies. For instance, 
in South Korea, dedicated studies of aquatic macroinvertebrate species facilitated 
