by Inez Tan

Many Singaporeans are extremely particular when ordering chilli crab (Is it male or female? How much does it weigh? Is the seller trying to cheat me?), but did you know that ‘flower crab’, or ‘blue swimmer crab’, can actually refer to four different species of crabs? All four were previously known as Portunus pelagicus, but NUS researchers recently discovered that despite looking similar, the crabs have different shell colour patterns, life cycles and even live in different regions. However, it is difficult to tell if any one of the species is in danger of being overharvested because fisheries classify them under the same name.

Herein lies the importance of taxonomy. ‘Since Diversity is an indicator of how well an ecosystem is doing, taxonomists have to find ways to differentiate creatures in order to measure it,’ says Mr James Koh (RI 1991), who often ventures into Singapore’s forests to photograph local fauna. One of the projects he had worked on as part of his postgraduate studies in Biodiversity, Evolution & Conservation involved mapping insect species based on the patterns of their wings.

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Gasteracantha mengei, an orb weaver whose abdomen fluoresces under UV light.

Taxonomic research can be painstaking—it involves comprehensive review of available literature and examination of documented specimens. Making this job all the more challenging is the fact that there are many cryptic species that look distressingly similar, and the only way to tell them apart is by examining their diagnostic features, such as genitalia, under a microscope. To complicate matters further, existing spider records can be messy because different researchers may have described the same spider species under different names.

Luckily, the Internet has made it easier for researchers to consolidate and revise taxonomic descriptions. Researchers can also glean preliminary information from digital images of specimens, which lessens the need to ship physical specimens across the globe. Many museums are now in the process of digitising their specimens for this reason.

‘Because many taxonomic illustrations are drawings of preserved specimens, natural history shots are especially helpful,’ shares Mr Koh. ‘Natural history shots show what the living animal looks like. However, the diagnostic features of the animals are sometimes obscured in artistic shots; for example, many people like to take face shots, focusing on a beetle’s eyes. But to diagnose a beetle species you may have to look at its tarsus (foot), or how it looks like from the top. And these are the kinds of shots I tend to take.’

Although he has always been fascinated with animals in their natural habitats, Mr Koh only began dabbling in nature photography in 2009, when he contacted Ria Tan, creator of the seminal Wild Singapore website and doyenne of nature conservation in Singapore. Armed with a camera in one hand and a flashlight in the other, they gingerly made their way along Changi Beach to photograph the myriad of marine creatures revealed by the low tide.

The shore was so rich,’ says Mr Koh. ‘It was so rich that it was difficult to not step on anything. There were sea stars, sea anemones, sea cucumbers, fish, crabs.’ On another trip, Mr Koh met fellow nature enthusiast Marcus Ng (RJC, 1993), who introduced him to terrestrial exploration. Since then, Mr Koh has been venturing into Singapore’s forests to capture their lush biodiversity with his camera lens. He has a soft spot for spiders especially: ‘if you think about it, a one millimetre-long spider can spin a web, operate eight legs and run away when it senses something coming. And it can even squash itself against a corner and pretend it’s not there! You can’t programme a robot to do the same thing.’

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A female two-tailed spider (Hersiliidae) guarding her egg sac.

Among the adorable (and sometimes fuzzy) local arachnids Mr Koh has photographed are spiders that look like ladybirds, spiders with jaws longer than the rest of their bodies, spiders that look like snakes, spiders that hunt in the blackest of night by sight, armoured spiders, spiders that carry their young on their backs, spiders that look like turtles, spiders that look like Howl’s Moving Castle, and even a rare spider named after a late musician: Heteropoda davidbowie.

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A gaudily painted spider, Heteropoda davidbowie. This huntsman spider was named after the late musician.
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Poltys is a genus of orb weavers that closely mimic bits of wood.
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An ogre-faced spider (Deinopidae). This family of spiders hunt at night by sight, and have eyes with an effective aperture wider than most camera lenses.
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A female feather-legged spider (Uloboridae) with her egg sac, which is longer than she is. This family of spiders catch prey using a single silk line.

Incidentally, some of the spiders that Mr Koh and his friends have found are not listed in Singapore’s spider records yet. No official database of Singapore spiders exists, but one popular resource is a comprehensive database built by Mr Joseph Koh, who has pledged to donate the 12 thousand preserved spider specimens in his collection to the Lee Kong Chian Natural History Museum. ‘Identifying spiders is hard work and takes a lot of time, so I would be happy if I can manage to successfully identify one spider a day,’ he says in a 2015 Straits Times interview. ‘This is not a job I can finish in my lifetime.’

‘[Joseph Koh] has very kindly taught me a lot about spider taxonomy—how to look at a spider under a microscope, what to look for, where to go to find information on spiders. He’s my shifu (mentor),’ laughs Mr James Koh.

Like many members of Singapore’s growing nature photography community, Mr Koh uses handheld home-made photography equipment that he has put together himself—a chopping board from Daiso became part of a softbox (especially important when photographing round, shiny arthropods), and a foil cooler bag acts as a reflective surface. Besides these, Mr Koh carries a flash, a flash arm, and a macro conversion lens that he clips onto his macro lens. Shots can turn out as beautiful as what can be achieved in a studio.

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Gasteracantha hasselti. Although it looks rather strange, this species of spider is actually quite common. It can be found at the edges of forests.

‘Right now there’s a growing demand for citizen science, which includes people like us who take natural history shots that scientists can use,’ Mr Koh points out. ‘Citizen science can also generate more public interest in environmental matters. It would be nice if people could start to take a keen interest in nature, rather than just taking from the forest and not giving it anything in return.

‘But the sad thing is that we have too many people. If more start to venture into the forest to photograph animals, that would also be a terrible thing.’ To find one such tragic example, look no further than Bukit Timah Nature Reserve—the daily influx of human visitors into this precious patch of primary rainforest has led to environmental degradation, and the reserve was eventually closed for six months in 2014. The soil had become increasingly compacted, erosion became more severe, and inconsiderate trekkers who strayed from the beaten paths to create more (unauthorised) beaten paths of their own had harmed the forest’s delicate ecosystems.

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Lysania sp., a wolf spider. Female wolf spiders carry their newly hatched young on their backs.

 

‘Because scientists are able to tell that species counts are dropping, it forms a solid basis for implementing policies that protect our forests,’ says Mr Koh. ‘But actually, while this information may be essential for prioritising which forests should be conserved, the bottom line is: if we wish for the survival of our species, we need to ensure that we do not alter our living environment at a rate that is too fast for evolution to keep up. Setting priorities without a complete understanding of nature is risky. We may be sacrificing long-term survival in our attempts to satisfy short-term demands.

‘So my advice to students is to always question: ask for the reason behind why things are the way they are, and to always try to see the bigger picture. I believe that that is one of the most important things a student can do these days.’

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