Skip to main content

Needlefish around Thailand’s Andaman Coast

crocodile needlefish patrol the shallows

I often see needlefish when snorkelling around the Andaman Sea shores of Western Phuket and Peninsular Thailand. Needlefish, or long toms as they are commonly known in Australia, are predators of (mostly) small fish; They inhabit surface waters where their long, slender form and silvery scales render them almost invisible until quite close.  I generally encounter them hanging around the periphery of reefs, or cruising around piers, just beneath the surface, and sometimes in very shallow water, surfing in on small waves to where the water is only a few inches deep. They patrol these areas in small groups of up to a dozen or so, moving like hunting dogs, looking to sneak close enough to an unwary sardine or silverside to pounce. Usually they will suddenly launch themselves forward at speed into the school of small fish, hoping to grab one as they scatter. Off heron Island, on Australia’s Great Barrier Reef, they have been observed to launch aerial attacks; leaping clear of the water, to land amongst the unsuspecting school of bait fish. I’ve never personally observed this and as far as I know it’s never been recorded around Thailand.

A crocodile needlfish patrols the edge of a pier, looking for unwary sardines to form its next meal.

Needlefish have a reputation for being dangerous to swimmers and fishermen. While far from aggressive (they’re actually quite timid and tricky to approach close) there have been a number of injuries and indeed some fatalities caused by needlefish. The problem is that when needlefish feel threatened, they will often leap out of the water; long, low leaps, travelling at speed and covering some distance. I’ve seen speeds of 40 mph through the air mentioned, though I suspect this is little more than a guesstimate.  With their long, thin needle-like jaws it’s easy to see how being unlucky enough to be stuck by one could cause serious injury. In November 2020, a Hawaiian man out sea canoeing found himself in the middle of 30-40 needlefish leaping out of the ocean. Several stuck his canoe, one puncturing straight through the fibreglass canoe hull. In Nha Trang, Vietnam, in 2014, a Russian tourist was swimming when she felt a sharp pain in her neck. She was rushed to hospital suffering partial paralysis.  Emergency surgery removed fragments of needlefish jaw, and teeth, from around her spinal cord.  Fortunately she made a full recovery.  Though incidents can be very nasty they are also, thankfully, very rare. Fatalities are extremely rare, but do happen. In 2018 a young Thai cadet training with Thai navy special forces died after hit him in the neck during a military training exercise.  

There are probably more incidents that go unrecorded; local artisanal fishermen are generally at much greater risk due to the amount of time they spend in the water or in small boats, especially at night. Lights, often used to attract fish, are known to attract or create panic in needlefish, causing them to leap out of the water. In Papua New Guinea, for example, where fishing at night from small wooden outrigger canoes is a very common occurrence, numerous injuries are recorded every year.  The use of lanterns to attract fish appears to increase the risk. (You can read more about the outrigger canoes of Papua New Guinea in my blog here)

Should you be unfortunate enough to be struck by a needlefish while swimming or wading it is absolutely imperative that you get proper medical attention. Injuries to the arms or legs may seem minor, but the fish beaks can penetrate deep.  Teeth and jaw fragments will also frequently break off, remaining un-noticed within the wound.  In 2015, a passenger on a Caribbean cruise was struck on the nose by a needlefish while wading in waist-deep water. This left what appeared to be only a small wound that healed quickly. Three months later, after persistent nasal problems, a 39mm long fragment of needlefish beak was removed from the man’s sinus, the tip only 5mm away from the left frontal lobe of his brain.  In 2013 a Japanese swimmer received treatment after being struck in the lower eyelid by a needlefish, the wound was cleaned and all fragments thought to be removed. Swelling persisted and a subsequent CT scan found two 25mm long fragments above his eye, which were then surgically removed.  There is also a high risk of infection from such wounds, so treatment with broad spectrum antibiotics is normally recommended after any injury.

This may all make the seas sound a very dangerous place, but it’s worth keeping things in perspective. These events are rare.  Lightning strikes kill thousands worldwide every year. Tens of millions go swimming or fishing in tropical waters every year and suffer nothing worse than mild sunburn. Maybe don’t go fishing at night in a small canoe, carrying a spotlight.

I took these photographs of crocodile needlefish (Tylosurus crocodylus) snorkelling off a beach just north of Phuket Island. I had been hoping to photograph the large schools of sardines that were hiding underneath the long concrete pier there. Unfortunately a plankton bloom coupled with windy conditions and a strong swell made that pretty much a non-starter.  Visibility of less than three metres was not going to produce great images of large schools of fish. In addition, the low visibility and significant swell did not fill me with enthusiasm for diving down under the pier, the legs of which were covered in a thick blanket of razor-sharp oyster shells. I’d learned to my cost than a bump against those was not a pleasant experience. However, gazing down from the top of the pier I could see number of needlefish patrolling the edges and surfing in on breaking waves. So despite the unpromising sea conditions, and the fact that my camera was set up with a very wide-angle lens – not ideal for getting close to timid fish – I decided I was there now and so might as well get in the water.

The first picture was taken along the edge of the pier. I wanted to catch a needlefish in the light, but have the dark shadows under the pier behind it. This sounded straightforward, but, in reality, involved a lot of slow dancing around the edge of the pier, trying to get close, with the sun at the right angle whilst avoiding getting washed against the pier legs. I would carefully line up a shot only to have the fish disappear into the green haze. Eventually I got one that was acceptable.

A couple of crocodile needlefish cruise past me in shallow water.

The second shot was taken close in to the shore, in less than a metre of water.  Here in the shallows the light levels were high, but plankton combined churned up sand to reduce visibility further still.  Half a dozen needlefish continually moved in to the shore, then turned and circled back out, moving in and out of my vision as I bobbed in the waves. I switched everything to manual, including focus given the turbidity of the water, and concentrated on firing off shots as we, fish and I, warily waltzed around each other. After around 30 minutes I decided it was time to get out. The wind was increasing, and so were the waves. If I hadn’t got useable shots by then it wasn’t going to happen.

Fine Art Landscape and Wildlife Prints

If you enjoyed this article why not check out my other blogs. I write about travel, the environment, marine biology, diving and wildlife. You may also want to check out my photographic prints. These can be viewed on my main site www.colinmunrophotography.com and include landscapes from around the World, people of the World, marine life and other wildlife. The prints are only available through my website, each one individual processed and made to order. This includes fine art giclee prints, limited edition prints and canvas wraps. I use only the best, carefully selected print houses employing the finest papers and printing processes to ensure image fidelity and longevity.

Some of the framed canvas wrap prints on my website. You can also check out my fine art prints and posters.

Pig-tailed Macaques of Thailand

Pig-tailed Macaques of Thailand
A northern pig-tailed macaque, Macaca leonina, thoughtfully inspects the back of its hand while grooming its fur.
A northern pig-tailed macaque thoughtfully inspects the back of its hand while grooming its fur.

Caught in shafts of light on the edge of the forest, a pig-tailed macaque is wholly absorbed as it inspects the fur on the back of its hand. The behaviour and pose are strikingly human, and reminded me of how much we have in common with our primate cousins.

This is an adult male northern pig-tailed macaque. Until quite recently pig-tailed macaques were considered one species, Macaca nemestrina, with the northern pig-tailed classed as a sub-species. However studies conducted in the early 2000s (e.g. Gippoliti, 2001) looking more closely at anatomical and behavioural differences, determined that the differences were so significant that they should be considered two distinct species. The southern pig-tailed macaque retained the original scientific name (M. nemestrina) while the northern pig-tailed macaque (previously the sub-species M. nemestrina leonina) was elevated to full species level and given the new scientific name Macaca leonina. However this change remained scientifically controversial until quite recently, and only in the past few years has it become fully accepted. The most recent (at time of writing) research on speciation of pig-tailed macaques in South East Asia, using analysis of differences in mitochondrial DNA proteins to determine molecular clock timelines, suggests that northern pig-tailed macaques separated from their southern brethren around 1.7 million years ago, and from the Siberut macaque of Western Indonesia only just over one million years ago (Abdul-Latiff and Md-Zain, 2021). Both northern and southern pig-tailed macaques occur in Thailand, with the boundary between ranges of the two species believed to lie in the Krabi region of Southern Thailand. I photographed this guy on the island of Phuket, which is very close to this boundary. The lighter colour fur, white flashes above the eyes and a thin red line running from the corner of the eye towards the ear, mark him out as distinctly a northern pig-tailed.

A northern pig-tailed macaque (Macaca leonina) looks straight ahead as it emerges from the shadows of the forest.
A northern pig-tailed macaque caught in sunlight with background in deep shadow. It can clearly be identified as a northern pig-tailed by the conspicuous white flashes above its eyes and the deep red lines running from the corner of each eye towards the ears. Phuket, Thailand.

Pig-tailed macaques are denizens of lowland and hill rainforest through much of South-East Asia. However in many locations their natural habitat is disappearing rapidly as rainforest are cleared to make way for palm oil and rubber plantations, rice paddy fields and urban development. Because of this northern pig-tailed macaques are classed as a vulnerable species by the IUCN. They are primarily fruit eating, but will also take leaves, birds eggs, insects and caterpillars, and are not averse to raiding palm oil and fruit tree plantations. Along with their relatives the crab-eating macaques (Macaca fascicularis) pig-tailed macaques have learned to live alongside humans. In Phuket the inhabit the forests and mangroves (in the case of crab-eating macaques) fringing towns and villages, especially along the eastern shores, and will often congregate in tourist areas drawn to handouts of bananas. The habituation to humans brings numerous problems. The monkeys develop a taste for the easy pickings of tourist handouts and the risks of infection and injury due to bites or scratches from fearless monkeys is significant. But for me it is the similarities between us that are the most fascinating; the strong social bonding, the way a youngster will play with a leaf or a discarded plastic drink bottle just like a small child, or the way an adult will stare at the back of his hand as if in deep introspection, and for all we know maybe he is.

References

Gippoliti S. 2001. on the taxonomy of Macaca nemestrina
leonina Blyth, 1863 (Primates: Cercopithecidae). Hystrix It J Mamm 12: 51–54. doi:10.4404/hystrix-12.1-4171.

Muhammad Abu Bakar Abdul-Latiff, Badrul Munir Md-Zain. 2021. Taxonomy, Evolutionary and Dispersal Events of Pig-Tailed Macaque, Macaca nemestrina (Linnaeus, 1766) in Southeast Asia with Description of a New Subspecies, Macaca nemestrina perakensis in Malaysia. Zool Stud. 2021; 60: e50. Published online 2021 Oct 8. doi: 10.6620/ZS.2021.60-50PMCID: PMC8685347

About these images

I took these shots late afternoon, on the edge of some forest on the eastern side of Phuket Island, Southern Thailand. The macaque had just climbed down from a tree and was perfectly lit by the low-angled sun, while the forest behind was in deep shade. The images were taken with a Nikon full-frame DSLR; the full size image is around 80 megapixels.

Fine Art Landscape and Wildlife Prints

If you enjoyed this story why not check out my other blogs. I write about travel, the environment, marine biology, diving and wildlife. You may also want to check out my photographic prints. These can be viewed on my main site www.colinmunrophotography.com and include landscapes from around the World, people of the World, marine life and other wildlife. The prints are only available through my website, each one individually processed and made to order. This includes fine art giclee prints, limited edition prints and canvas wraps. I use only the best, carefully selected print houses employing the finest papers and printing processes to ensure image fidelity and longevity.

My gecko house-mates: noisy tokays, third eyes and superpowers

My gecko house-mates: noisy tokays, third eyes and superpowers

I have a lodger.  To be more precise I have at least two lodgers. They are tokay geckos. Living where I currently do, in semi-rural southern Thailand, tokay (sometimes spelled tockay) geckos are pretty much everywhere, and they let you know it.  Each evening I hear their calls echoing across the tracks that lead to my house. ‘Tok-kaaay ……tokaaay’ booms in the darkness, sounding more like a demented parrot than a shy lizard.  Among lizards, geckos are well known for being the noisy buggers.

A pair of Tockay geckos watch and wait for the sun to set before leaving the safety of their shelter under a house roof. Phuket, Thailand. © Colin Munro Images

A pair of Tokay geckos, the larger male above, watch and wait for the sun to set before leaving the safety of their shelter under my house roof.

Most reptiles are fairly quiet, maybe the angry hiss if you disturb them, but otherwise you don’t hear them much. Geckos are the loud guys at the party, and they achieve this by having true vocal chords. We’ve known geckos have vocal chords for a long time, since 1839 in fact, when the German physician and anatomist Friedrich Gustav Jakob Henle published the monograph:  Vergleichend-Anatomische Beschreibung des Kehlkopfs: Mit Besonderer Berücksichtigung des Kehlkopfs der Reptilien (Comparative anatomical description of the larynx: With special consideration of the larynx of the reptiles).  For the biologists among you, this is the self-same Henle that the ‘loop of Henle’ within our kidneys is named after.  Although primitive compared to mammals or birds, the larynx, vocal chords and associated structures found in geckos are quite sophisticated compared to other reptiles.  This adds not only volume to their calls, but also allows a wide range of sounds to be made, with specialised warning calls and mating calls.  The loud, two syllable ‘Tok-kay’ bellow from tokays is produced by the male, aimed at attractive females with his authoritative, manly voice and simultaneously deterring male competitors with his .auth … you get the idea.  Where I live I clearly hear ‘Tok-kaay’ when my resident male tokay advertises his presence. But other people here something different. Many people here ‘Gek-koh’; indeed, this vocalisation is the reason behind its scientific name, Gekko gecko.  Now this may be partly that we interpret sounds differently, but there is more to it than that.  Recent studies have shown not only considerable range in sounds emitted by tokays, but that there appears to be significant regional variation (Yu et al., 2011). Simply put, tokay geckos have local accents. So maybe my southerner tokays really do say ‘tok-kay’ while those rough northerners say ‘gek-ko’.  I’m sure there’s a research paper in there for someone.

As geckos go, tokays are big. A full grown male can be 30cm (12 inches) long.  The largest known gecko, Leach’s giant gecko, can grow to about 36cm (14 inches) long, so tokays are not that far behind.  But more than that, they are quite beautiful (which you’d find hard to say about Leach’s giant gecko).  The ones here are light blue-grey and covered in vivid orange-red spots, complete with huge dark green eyes.  Two colour morphs are known; to the north and east of their range tokays have black rather than red spots. Currently only two subspecies have been identified; the common or garden tokay: Gekko gecko gecko, which occurs all the way from India to Southern China (and incidentally includes red and black spotted morphs) and the rather elusive Gekko gecko azhari, described by Mertens in 1955 and known only from Bangladesh.  Once more genetic studies are completed it may be that we find that tokays are really a ‘species complex’ rather than a single species.

Tokays have yet another unusual feature, a rudimentary third eye (known as a pariental eye) on the top of their heads.  Pariental eyes are found in a great many creatures: many reptiles and amphibians and some fish species (but not in birds or mammals). It does not form an image, like the paired visible eyes, but is sensitive to changes in light levels. The pariental eye is essential an outgrowth of the pineal gland, a small endocrine gland deep within the brain.  The pineal gland is especially known for producing melatonin, the hormone, many of you will know, responsible for regulating sleep patterns (and sometimes sold as a supplement to counteract jet-lag or insomnia). The pariental eye, via the pineal gland, is thought to regulate circadian rhythm (day-night sleep cycle) and seasonal rhythms in activity, by reacting to changing light levels.  Although we do not have a pariental eye, we do have a pineal gland, indeed almost all vertebrates do, and it preforms the same functions in us, letting our bodies know when to sleep and when to wake up, as it does in tokays and other reptiles.  The difference appears to be that we get our visual cues to light levels through our paired eyes.  Which then begs the obvious question; so… er geckos, and monitors, and frogs have paired eyes as well; so why do they need to growth a third eye in order to monitor light levels?  It’s a tricky question.  It turns out that maybe the pariental eye isn’t just about providing information on light levels to regulate sleep patterns.  Numerous studies from the mid-1970s on have shown that, in many different lizards, the pariental eye is directly involved in regulating behaviour related to thermoregulation. Lizards are cold-blooded (ectotherms, to use the scientific term). That means they cannot internally regulate their body temperature; they take on the temperature of their environment.  Consequently, in order to keep their body temperature within the range where their muscles will work well and the body’s chemical reactions occur at the correct rate, they must adopt specific behaviour patterns.  Basking in sunlight to warm up, moving to shade to cool down.  Well it turns out that without the information from the pariental eye, lizards don’t do that; their behaviour becomes a little more random.  For tokays it’s a little different. They are nocturnal, so they can’t really move to bask in sunshine to warm up … or move to shade to cool down. In fact, they are known as thigmothermic, which is a fancy way of saying they warm up or cool down by touching warmer or cooler surfaces. An interesting observation is that the two major groups in which pariental ‘third’ eyes are never found are birds and mammals.  Of course the other key feature these two share is that they are warm blooded (endotherms: they regulate their internal temperatures irrespective of external temperate). Recent studies of fossil evidence tend to suggest that, in the predecessors of modern mammals, the pariental eye disappeared around about the same time as warm-bloodedness evolved. (Benoit et al. 2016)   As luck would have it, the disappearance of a third eye is fairly easy to identify in the fossil record as the connecting nerves fibres pass through a small hole at the top of the skull. So it would seem, for reasons still not fully understood, the real need for a third eye is to allow cold-blooded animals to thermoregulate.

Tokay gecko on vertical wall © Colin Munro

With seemingly no effort, a tokay gecko sticks like glue to a vertical vertical wall

I’ve digressed quite a long way for geckos though, so let’s move back to them. Probably the ‘superpower’ that geckos are most famous for is the ability to run up, and cling to, smooth sheer surfaces.  Apart from my tokays, I have many house geckos living, surprise-surprise, in my house.   If you’re going to be picky, these are spiny-tailed house geckos (Hemidactylus frenatus).  They’re mostly pretty unobtrusive fellas. They eat a fair few mosquitoes, so that’s always a good thing, if fact they eat most things smaller than themselves, including juvenile house geckos.

A spiny-tailed house gecko pounces on, and starts to devour, a smaller house gecko that carelessly strayed too close. © Colin Munro

A spiny-tailed house gecko pounces on, and starts to devour, a smaller house gecko that carelessly strayed too close.

But they’re quiet and generally well-behaved lodgers, apart from leaving lots of gecko crap on the floor for me to sweep up every morning.  I mostly see them running across walls, or across my windows chasing prey and squabbling with each other.  They cut an eerie form when caught in the light, on the outside of frosted windows.

A spiny-tailed house gecko waits and watches on the outside of the frosted glass in my kitchen window © Colin Munro

A spiny-tailed house gecko waits and watches on the outside of the frosted glass in my kitchen window

There have been various theories advanced over the years as to how exactly geckos achieve this.  From suction pads to Van der Waals forces (intermolecular forces created by fluctuating polarisations of nearby particles as a consequence of quantum dynamics …. can you tell I’m out of my depth here?).  Each toe is covered in rows of wrinkled skin forming parallel ridges (like they’ve stayed in the bath too long); these in turn are covered in tiny spatula-like bristles (lamellae).  Capillary action (think of two sheets of glass stuck together with a thin film of water between) between these spatula-like surfaces and the walls is believed to part of the answer. Van der Waals forces (description above, I’m not repeating it) is also thought to play a part. However, recent studies suggest that actually the major force is electrostatic, and that is what primarily allows to gecko to cling to impossible surfaces (Izadi, Stewart and Penlidis, 2014).  So currently, our best guess is it’s a combination of things that give the geckos their ‘superpower’. Whether this is the definitive answer, or whether someone will come up with new evidence for a different explanation, time will tell.  One thing we do know is that it is pretty impressive. Researchers William Stewart and Timothy Higham, of University of California, Riverside, found that tokay geckos were in a league of their own here.  In lab experiments where they attached pulley weights to tokays that climbed up an acrylic sheet, they found that it took up to 20 times their bodyweight before they started to slip.  That’s the equivalent of an 80kg ((~180lb) man gripping on to vertical acrylic, with a saloon car strapped to his back.  This is real Marvel superhero territory.  But even more extraordinary still, the researchers found that the grip remained just as strong in dead geckos.  So when I look at geckos on my wall, and they seem to be hanging on with no physical effort whatsoever, well that’s probably true.  So next time you see a tokay gecko looking striking with blue-green skin and bright orange-red spots remember, that’s it’s superhero costume it’s wearing.

All text and photographs © Colin Munro

References.

Benoit, J., Abdala, F., Manger, P.R., and Rubidge, B.S. 2016. The sixth sense in mammalian forerunners: Variability of
the parietal foramen and the evolution of the pineal eye in South African Permo-Triassic eutheriodont therapsids. Acta Palaeontologica Polonica 61 (4): 777–789.

Stewart, W.H. and Higham, T.E. 2014. Passively stuck: death does not affect gecko adhesion strength. Biol. Lett. 10:20140701. http://doi.org/10.1098/rsbl.2014.0701

X. Yu, Y. Peng, A. Aowphol, L. Ding, S.E. Brauth & Y.-Z. Tang (2011).  Geographic variation in the advertisement calls of Gekko gecko in relation to variations in morphological features: implications for regional population differentiation. Ethology Ecology & Evolution, 23:3, 211-228, DOI: 10.1080/03949370.2011.566581