Multiple records of aquatic alien and invasive species in diets of native predators in Singapore

Ding Li Yong,Alene Ang,Bing Wen Low,Clarissa Ho,Meiling Woo

doi:10.3391/bir.2014.3.3.11

Abstract

We report for the first time the diversity of known aquatic alien species in the diets of four piscivorous predators in Singapore through a review of published and unpublished studies, and our empirical data. Of 15 aliens identified to the species level, 11 were fish, including the highly invasive tilapia (Oreochromis mossambicus [Peters, 1852]). Other alien species include the abundant red-eared slider (Trachemys scripta elegans [Wied-Neuweid, 1839]) and the American bullfrog (Lithobates catesbeiana [Shaw, 1802]). We hypothesize that the diversity of established alien species in Singapore’s aquatic habitats allows for novel ecological interactions, one of which is predation by native species. Our study provides preliminary evidence that alien and invasive species may benefit some native piscivores as a source of prey although it is not possible to infer relative composition of these alien species given our limited data. Future studies should investigate the ecological dynamics of these interactions, including the relative importance of these alien prey to diets and survival of predators.

Highlights

The threat posed by alien and invasive species to native and endemic biodiversity in Southeast Asia remains poorly understood despite the fact that many alien species across multiple taxonomic groups are established in many Southeast Asian countries (Pallewatta et al 2003; Tan et al 2010; Wanger et al 2011)
A total of 15 alien species are identified from the diets of the four predators examined, including 11 fish species (Table 2) from five families: Characidae, Cichlidae, Cyprinidae, Pangasiidae and Poecilidae
Despite its known abundance in the water bodies surveyed for grey-headed fish eagle, we did not record it in the diet of that species

Summary

Introduction

The threat posed by alien and invasive species to native and endemic biodiversity in Southeast Asia remains poorly understood despite the fact that many alien species across multiple taxonomic groups are established in many Southeast Asian countries (Pallewatta et al 2003; Tan et al 2010; Wanger et al 2011). One example is the city state of Singapore where a bustling pet trade (Goh and O’Riordan 2007; Ramsay et al 2007) and aquaculture industry (see Naylor et al 2001; Ng et al 1993; Liew et al 2013), together with deep-rooted religious (Tan 2004) and culinary traditions (Tan et al 2010), continue to act as conduits for arrival of alien species into Singapore’s natural environments This is further supplemented with accidental introductions arising from biological control projects (Sodhi and Sharp 2006; Tan et al 2010) and marine transportation (Yeo et al 2009). Predation of invasive or potentially invasive alien species may help limit or even control the invasion of these species (Madenjian et al 2011)

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Conclusion