Joleen Chan

Supervisor: Dr. Darren Yeo Chong Jinn

Project: Investigating fish and macroinvertebrate diversity of macrophyte communities in reservoirs around Singapore

Invasive alien species are known to cause harm to the local environment and its native species. Singapore, being one of the world’s busiest ports, and the world’s largest exporter of ornamental fish (more than 50% of which are imported and re-exported), is highly susceptible to the introduction of exotic fish. It is thus important to evaluate the potential of imported/introduced fish species to become invasive. This project aims to perform such an evaluation through both quantitative and semi-quantitative methods. The former involves performing a trait-based risk assessment of alien fishes in Singapore, while the latter focuses on the calibration and development of a fish invasiveness scoring kit (FISK). Results of these analyses could serve as a useful baseline and tool for the identification of potentially invasive fish species to help inform potential management strategies by government agencies (e.g., preventing introduction of high risk invasive species through control of imports/sale, or slowing spread or managing impacts of already introduced invasive species).

Joanne Song Zhu En

Supervisor: Dr. Darren Yeo Chong Jinn

Project: Habitat and dietary preference of golden apple snails (Pomacea species) and their impacts on freshwater snail diversity

The golden apple snail (Pomacea canaliculata) is a notorious invasive or pest species found in Singapore’s urban fresh waters (e.g., reservoirs). Potential impacts posed by the species include the decline of other snail species through competition for food resources. Apple snails have voracious appetites, feeding on both floating and submerged macrophytes and occasionally, small fish. In Singapore, populations of native snails like Pila scutata have declined while populations of Pomacea have increased. Studies to find out the potential impacts of apple snails on other freshwater snails in reservoir habitats (where Pomacea are abundant) are thus needed. Hence, the purpose of my study is to determine if there is a dietary and/or habitat overlap (with respect to depth) between golden apple snails and other freshwater snails, as well as to determine if the diversity of other freshwater snails are impacted by the dietary and habitat preference of golden apple snails. 

Ng Di Sheng Dickson

Supervisors: Dr. Darren Yeo Chong Jinn & Dr. Rudolf Meier (EvoLab)

Project: A preliminary study of aquatic leeches in Singapore

Aquatic leeches are important ectoparasites and predators in aquatic systems throughout the world. In Singapore, they are found in both natural as well as artificial aquatic habitats. However, they are very poorly studied in Singapore; besides a lack of understanding of their ecological role in our freshwater ecosystem, we do not even know exactly how many and what species exist in our water bodies. The first part of my project involves discovering and documenting the leech fauna in Singapore. I will be going to the different water bodies in Singapore to search for leeches, and finding out their identities and taxonomic placement using morphological and molecular approaches. The final aim is to publish a species list and identification key for the aquatic leeches of Singapore. The second part of my project involves analyzing the diet of the Asian buffalo leech, which are found in Singapore’s forest streams, using Next Generation Sequencing techniques. This should allow us to better understand their function in our ecosystem for better appreciation of these slimy critters. This also serves as a proof of concept for biodiversity research using metabarcoding for diet analysis.

Gan Da

Supervisor: Dr. Darren Yeo Chong Jinn & Dr. Tan Koh Siang

Project: The effect of salinity levels on the settlement, development, and growth of Mytilopsis sallei larvae

Mytilopsis sallei is an estuarine bivalve species that has been introduced into East Asia from the Central America. Increase in trans-oceanic vessel traffic is believed to have facilitated the spread between and across regions. Having wide salinity, oxygen, and temperature tolerance levels, it has since become established in this region. Though the species is well studied, surprisingly little is known about its larvae, and the conditions they need to settle and grow. As a potential biofouling agent, a study of the larvae (spawning, optimal conditions for settlement and growth) will bridge an important knowledge gap and benefit organisations and countries with high traffic of trans-oceanic vessels that are dealing with biofouling and ballast water issues. Understanding the larvae and how salinity affects their settlement, development, and growth, will also help us to better understand its geographical range. This may shed light on why Mytilopsis sallei adults propagate in some areas but not others even though these are within the physiologically tolerable range (e.g., whether larvae are present but unable to settle, grow, or survive; or whether larvae are simply not present).