A small stream by the edge of the forest reserves proper. The water is clear and cool, and a fence of trees shade the flow from the harsh strength of the sun. It looks idyllic, but the hand of men has already reshaped this habitat from its original state. Apart from the swaying stems of aquatic sedges (probably Eleocharis sp.) on the stream bed above, most of the other submerged and rheophytic plants along the waterway are not native to Singapore. The taro yam (Colocasia esculenta) growing on the bank has been cultivated and distributed by civilisations across the Western Pacific for so long that its origins are now obscured. In the more exposed parts, rosettes of Echinodorus bloom with a shower of stalks bearing three-petalled flowers. South American by nature, these plants are most commonly known as swordplants, and many aquarists are baffled to discover that these fish shop staples have emergent forms, a phenotypic response to the seasonal flooding of their homelands.
From less far far away are the aroids in the genus Cryptocoryne. Distant cousins of the taro yam and money plant, these aquatic plants are increasingly threatened by habitat destruction in Sri Lanka, Singapore, Malaysia and Indonesia, their hub of biodiversity. As many aquarists would know, cryptocorynes are delicate creatures, hating change and reacting badly (and often fatally) to fluctuations in water conditions, turbidity and substrate. Hence, most species are seldom able to recolonise disturbed habitats. And even as their freshwater swamps and sheltered rainforest streams lose ground to loggers and land developers, more species are being found (or found extinct) with shocking regularity. The stream in question borders some plots that used to be agricultural land, including small farms that grew aquatic plants. Hence, it's not surprising that hardier members of the genus have escaped and colonised the stream. C. pontederiifolia (shown with a clump of Rotala sp. in the large photo) originates from Sumatra while the species on the top right is probably C. undulata or C. wendtii, both from Ceylon. The natives are no longer present, save in the upper reaches of the stream. There, native Bettas and shrimps still play in the leaf litter. Down here, only common barbs (Systomus binotatus) and halfbeaks remain to represent the original piscine fauna. They are joined by guppies (origin: Trinidad) and clusters of Hydrilla and Hydrocotyle, old favourites that have crept from goldfish bowls into foreign holes.
What cock you are writing?
Posted by: Cocktalking | 08 June 2007 at 10:08 AM
Hi, can I know where is this locality? I working on a project on freshwater crabs in Singapore. This habitat may hold freshwater crabs. Thanks
Posted by: Daniel Ng | 10 September 2007 at 10:53 PM
please email me, Daniel.
Posted by: budak | 11 September 2007 at 12:03 AM