The whiskered myotis is believed to be a common and widespread species in Singapore with the tendency to roost inside the rolled central leaves of banana plants (Baker & Lim, 2012: 148) as shown in the featured observation. A roost may contain from one to ten individuals, and the species also occasionally roost at the entrance of caves that are covered by vegetation. This bat tends to forage in tree-fall gaps and at the edge of vegetation (Kingston et al., 2006: 128-129).

This inoffensive and distinctive fossorial snake grows to 45 cm in total length. In Singapore, it is rarely seen, and is there regarded as a ‘critically endangered’ species (Lim, 2008: 264). It has been recorded from the Central Catchment Nature Reserve and Pulau Ubin (Baker & Lim, 2012: 90).

Although the white-spotted eagle ray was recorded from Singapore since 1861 (Bleeker, 1861: 38, as Aetobatis narinari), it appears to be locally rare. This species can grow up to at least 3 m in disc width, and is recognised by its long and broadly rounded snout with a V-shaped nasal curtain, and numerous white spots covering the blackish dorsal surface of its body (Last et al., 2010, as Aetobatus ocellatus). Previously known as Aetobatus narinari and Aetobatus ocellatus, the present scientific name of this Indo-Pacific species is Aetobatus mula (see Kottelat, 2013: 29).

The present observation appears to be the first record of this apparently introduced species in the southern part of Singapore Island. It was previously found in Mandai, Khatib Bongsu, Lim Chu Kang, Sungei Buloh (Baker & Lim, 2012: 112) and Punggol (Tan & Lim, 2013).

The specimen appears to have been run over by a bicycle. It was collected and deposited at the Zoological Reference of the Raffles Museum of Biodiversity Research at the National University of Singapore, under the catalogue number ZRC 2.7018. An introduced species in Singapore, it feeds on terrestrial mollusks and frequents exposed vegetated habitats

The White’s tree frog is native to northern and south-eastern Australia and southern New Guinea. It inhabits a large variety of wooded habitats, frequently in human dwellings (Cogger, 2000: 132). Males tend to be smaller than females and can be recognised by their darker throats with relatively looser skin. This hardy, long-lived (age of captives known to exceed 15 years) amphibian can be captive-bred, and is a popular pet (Bartlett, 2006: 121-123, as Pelodryas caerulea). As this species is available in the pet trade in Singapore, the five examples were likely to have been deliberately released. It is not known if there were any others left in the Lim Chu Kang area. All five individuals appeared to be in relatively good condition. They are either very recently introduced, or they have adapted well to the rural environment at the area. White’s tree frogs are animals of the tropics and sub-tropics, and from the calling males in this observation, seem capable of establishing feral populations in Singapore. It remains to be seen if this has already happened Feral examples of the White’s tree frogs have been recorded in New Zealand and Florida (USA), having reached those places possibly as stowaways in cargo or accidentally introduced via the pet trade. However, there have been no published accounts of this species having established breeding populations outside its native range (Kraus, 2009: 170). The burning sensation in the eyes experienced by one of the contributors shows that the glandular secretion of this species will irritate mucous membranes that also include nose, mouth, and open wounds (see Bartlett, 2006: 123, as Pelodryas caerulea). While little is known about its toxicity to humans, the skin secretion of Litoria caerulea was found to exhibit repellent properties against blowflies and mosquitos (Williams et al., 1998, 2006).

Hydrocotyle verticillata (whorled pennywort) is an exotic aquatic macrophyte that is primarily planted in canals and water features in Singapore for aesthetics and phytoremediation. It has now been found in multiple localities in Singapore Island, having spread out of original planting zones into adjacent lawns. Additionally, several spontaneous populations have been found in housing estates which could have been introduced through the ornamental trade or dispersed propagules of planted individuals. This species is also often confused with Centella asiatica (Asiatic pennywort), a native species, which could be a reason for its widespread planting. A Weed Risk Assessment (WRA) was performed, and a score of 20 was obtained (the high risk threshold for aquatic plants is 19), indicating it as a highrisk species. A comparison table to distinguish Hydrocotyle verticillata, Hydrocotyle sibthorpioides, and Centella asiatica is included. We recommend for Hydrocotyle verticillata a status in Singapore of casual but with a high risk of naturalising, and also more stringent measures for the importation of this species. Replacement with a suitable native species is advisable, and a WRA should be undertaken for any future exotic species for introduction.