Hemidactylus brookii is distinguished from other house dwelling geckos in Singapore by the rows of granular scales and tubercles on the dorsum and the large spiny tubercles on the dorsal surface of the tail (Das, 2010: 220). The species has been reported from Singapore in 1864 where it was said to be common in houses (Grismer, 2011: 478). However, there were apparently no records since then, and its presence in Singapore has been considered doubtful (Sworder, 1925: 64 as Hemidactylus brooki). In the region around Singapore, the Brook’s house gecko is known from Borneo and Peninsular Malaysia as far south as Pulau Pangkor (Grismer, 2011: 478). Considering that this species is a human commensal, it is most likely to be introduced in Singapore. The geckos in the present observation could have recently arrived on the coconut mats on the grass slope.

Believed to have been brought into Singapore on imported ornamental plants, the brown anole has mostly been restricted in the Marina Bay area (Tan & Lim, 2012). However, an individual has recently been spotted in a residential estate in Bishan (Woo & Wee, 2015), and the present sighting indicates that it has spread further inland on Singapore Island. The brown anole is suspected to be invasive in Florida, USA, where it could have driven the decline of the native green anole (Anolis carolinensis) by feeding on its hatchlings (Meshaka, 2011). This species is also reported to have significantly altered ant communities in betel-nut palm plantations in southern Taiwan (Hwang, 2008). It is not known if it would negatively impact native biodiversity in Singapore (Tan & Lim, 2012).

While the Argyrodes sharing the web with the Nephila are kleptoparasitic associates of the larger spiders (Koh & Leong, 2014), the flies featured here are not kleptoparasitic flies that are sometimes observed feeding on the prey of spiders (see Aldrich & Barros, 1995). They are tentatively identified as biting midges in the genus Forcipomyia. These flies are known to be ectoparasites of large insects (e.g. dragonflies, moths) and feed on the haemolymph of their victims. Forcipomyia associated with spiders was first recorded from Guinea, Africa (Clastrier & Legrand, 1991).

The blue land crab (Discoplax hirtipes) was recently rediscovered in Singapore on Saint John’s Island in July 2015. It had not been seen in the country since 1938 (Khew, 2015). The brown land crab, Cardisoma carnifex is distinguished from Discoplax hirtipes (previously as Cardisoma hirtipes) in having a sub-ovate (vs ransversely ovate) carapace, and short or no (vs. long and stiff) setae lining the merus of its legs. This completely terrestrial crab, which attains 12 cm carapace width, lives in deep burrows near the sea, often in back mangrove. It is widely distributed across the tropical Indo-west Pacific and is present in surrounding areas in Malaysia and Indonesia (Ng, 1998: 1148-1149). Although, the presence of Cardisoma carnifex in Singapore is not unexpected, the featured individual was found about 4 km from the sea and there is no mangrove habitat in close proximity. It is likely to be an escaped pet, but this species is not offered for sale in Singapore’s pet stores. Cardisoma armatum, readily distinguishable from Cardisoma carnifex by its bright red legs, is frequently imported from its native West Africa and sold locally as pets. Despite this apparently being the first record of Cardisoma carnifex in Singapore, its presence there does not appear to be natural (Peter K. L. Ng, personal communication).

The brown land crab is first recorded from Singapore Island based on an example of about 8 cm carapace width photographed at the Nanyang Technological University’s Jurong Campus in June 2015 (Lee et al., 2016). Because the example was found in an urban area some distance away from mangrove, it is believed to be artificially introduced there. The present specimen was obtained at the edge of mangroves, which is appropriate habitat for this crab (Ng, 1998: 1148-1149), and its occurrence there is thus considered natural. The specimen is deposited in the Lee Kong Chian Natural History Museum at the National University of Singapore under the catalogue number ZRC 2016.0305.

The contributor has seen this species in the immediate area before. The brown spiny rat is regarded as an endangered species in Singapore

The brown spiny rat inhabits rainforest habitats, and is regarded as an endangered species in Singapore (Lim et al., 2008)