Crawling with 1000 legs
THE name millipede means ‘one thousand legs’. In my zoology lectures I have taken great pleasure in telling my students that there are no millipedes with a thousand legs: until last year that is.
In 2021 a new species, Eumillipes persephone, was described. The beast was first discovered during exploratory mineral drilling in Western Australia.
It was collected from 60m below ground. When a few juveniles were found in some of the drill holes, the researchers set a trap and collected five adults.
Quite apart from the revelation that there is life at such depths, the adults had an unprecedented 1306 legs (the previous record was 750, also a burrowing millipede).
Why so many legs? It is believed that possessing so many helps the animal push through compacted soil.
The generic name Eumillipes means true thousand legs, while persephone is a tribute to the daughter of Zeus who, in Greek mythology, was taken to the underworld.
Fifty-seven millipede species have been recorded from Fiji (the ones you are likely to see indoors or on your verandah are introduced). But if you live anywhere near the bush the chances are that you are familiar with one of our rainforest giants (yaliva) in itaukei.
This familiarity may not stem from visits to the bush, instead the bush may. Our giant millipedes have the rather disconcerting habit of ending up in houses. When they do, the usual reaction is one of incredulity.
I well remember my first introduction to one of these antediluvian creatures. It was on the concrete surround of the Governor’s pool at Nadarivatu when I was about eight years old.
The smaller you are, the bigger these things look. This animal loomed large in my imagination for many years. No one I told about the encounter ever believed me.
It was with some relief that I reacquainted myself with these lovely creatures when I returned to Fiji.
I have to admit that most normal people do not find these creatures beautiful.
Average adult size is around 20cm but I have seen bigger ones, up to 25cm. The world record for a millipede is around 30cm so if you find one this big you stand a chance of gaining Fiji a place in the Guinness Book of Records.
In the Silurian period (over 400 million years ago) they grew to massive sizes. One species, Arthropleura armata, reached 2.5 m in length and is the largest terrestrial invertebrate ever recorded.
Nearly all millipedes are detritivores, that is they feed on decaying organic matter. While this is usually plant material, our monsters are not averse to chewing on a bit of dead flesh if they can get it.
I once made the very bad mistake of leaving a couple of tree frogs in the same damp pillowcase as a giant millipede (damp pillowcases are great for keeping various creepy crawlies in and are well recommended).
The following morning the frogs were dead, and the millipede had eaten a substantial amount of skin off one of the corpses.
Although this appears quite macabre, the breakdown of organic matter is essential to the well-being of the rainforest.
One could argue that the giant millipedes, and their smaller brethren, provide a kind of rubbish processing service.
Although the giant millipedes are apparently benign, my story about the dead frogs indicates caution.
Further support for treating these gentle giants with respect came after a visit to the Monasavu dam as it was filling.
When the water level rose, the rainforest trees slowly became inundated. Many creatures were forced up the still emergent branches.
We drove around these by boat and were able to collect large numbers of giant millipedes. I once described them as looking like salamis in a delicatessen, collecting them was a simple matter as they put up no resistance.
They went into a plastic cookie jar and there they stayed overnight. The following morning the jar was completely opaque.
Some chemical given out by the millipedes caused a reaction with the plastic.
The cookie jar was honourably retired from cookie service and became number one animal jar for several years after that.
My then wife, who did not know I had appropriated it, was not amused.
On one visit I collected two giant millipedes for a Television New Zealand (TVNZ) documentary team to film.
As I expected from prior experience, when stressed they exuded a brown liquid. I sniffed this a little incautiously to violent effect.
In a totally reflexive reaction, I violently snapped my head away from the penetrating pungent odour. I did this so powerfully that I gave myself whiplash and had a sore neck for days afterwards.
Millipede 1- Paddy 0. Normally the odour is almost pleasant, herbal with overtones of glue. Up close the effect is devastating.
On the skin, the brown fluid causes little effect, to me anyway. One TVNZ member suffered a skin reaction. In all cases the initially brown-stained patch of skin soon turns bright red and remains so for several days.
Some millipede species produce hydrogen cyanide gas. This is a direct equivalent of the binary nerve gases stocked in a few too many world arsenals.
The harmless precursors are stored in separate storage areas and explosively mixed in an expansion chamber when required.
The hydrogen cyanide gas so produced is forced out of an aperture to the outside. At close quarters this ultimate in chemical warfare kills over-zealous predators.
During the night these marvellous beasts trundle around the forest floor looking for food. During the day they hole up in a dark place and mind their own business. Nobody really seems to know a great deal about them.
We know that they belong to the genus Salpidobolus but after that your guess is as good as mine. A recent check list includes 30 species from Fiji but how many there really are is an open question.
The last time a new species of giant millipede from Fiji was described was in 1920 and Chamberlin, the scientist who did the describing, did not include drawings which makes subsequent identification very difficult. It may be that different people have described the same species under different names and that we actually have considerably fewer species.
However, millipedes don’t move very far or fast, a river or a mountain range may be all that is required to isolate a population long enough for speciation to occur. Thus, there is the fascinating possibility that 30 species is an underestimate.
My friend, Richard Markham, photographed an extraordinary 15cm long cream coloured millipede near Savsavu, presumably a Salpidobolus species and possibly new to science.
Millipedes carry out internal fertilization. The male transfers sperm into modified legs called gonopods during faceto-face copulation and he uses these to deposit sperm into female receptacles called cyphopods.
The female uses the stored sperm to fertilize the eggs. Most species deposit the eggs and leave them, but some protect the eggs inside silk cocoons. When the young hatch, they typically have 3 pairs of legs but add extra legs and segments as they grow.
Motyxia millipedes in California, USA, are bioluminescent. To the best of my knowledge no Fijian millipedes are bioluminescent, but Elisabeta Waqa and I found a rain forest millipede that fluoresced under UV (black) light while we were looking for scorpions.
But that is a tale for another day.
In the meantime, we must preserve as much rainforest as possible to save these and the many other fascinating animals and plants that are yet to be found within our bush.
Short term financial gain for the already rich does little for long term development. Perhaps I am biased, but I feel that these ancient looking creatures are just as much a symbol of Fiji as our worldrenowned iguanas.
In a world gone mad with territorial claims, dubious politics and rampant pollution, Fiji’s giant millipedes are a vivid reminder of an unspoiled past. Have a happy week, keep smiling.
■ Dr PADDY RYAN is the author of Fiji’s Natural Heritage and a contributor to The Sunday Times. He taught at USP for many years and now works as a personal trainer and university professor in Denver, Colorado. The views expressed are his and not necessarily
shared by this newspaper.