Wednesday, June 12, 2013

Centipedes (Phylum Arthropoda: Class Chilopoda) of Singapore

Centipedes (phylum Arthropoda, subphylum Myriapoda, class Chilopoda) are arthropods with an elongate and flattened body made up of at least 16 segments. Each segment has one pair of legs. Interestingly, they always have an odd number of pairs of legs, with the last pair longer than the rest, and the first pair modified into venomous fangs (or forcipules).

They are from the subphylum Myriapoda, which typically comprises elongate arthropods which possess numerous pairs of legs ("myriapoda" means "10,000 legs" in ancient Greek), a trunk with many segments, and a head with one pair each of mandibles and antennae at the front end.

Like other arthropods, they have jointed legs ("arthropoda" means "jointed legs" in ancient Greek), a bilaterally symmetrical body, and a tough exoskeleton (or external skeleton) composed largely of a tough material called chitin. As they grow, they need to moult, i.e. discard the old skeleton and grow a new one. Their cuticle (i.e. outer covering) is not waterproof, and hence they are largely terrestrial. Most species are also nocturnal to avoid water loss, and are most readily found in damp habitats such as the leaf litter or underground. They can breathe by taking in air through openings in the cuticle.

They use their venomous fangs to hunt smaller animals, which can include both vertebrates and invertebrates. While the venom is generally not fatal to human, been bitten by the bigger species can be very painful. The victim may also experience headaches and nausea for a few days, and the bitten area may swell up. Death cases are extremely rare, unless the victim is allergic to the venom. To breed, the males usually drop the sperm on the ground that the females pick up. The eggs may be laid singly or brooded in batches underground.

A) Order Scolopendromorpha

Scolopendromorph centipedes are usually large and robust with large fangs that can give very painful bites. They often come in bright colours, sometimes with stripes, and possess either 21 or 23 pairs of legs. They can move relatively fast, and the females tend to be more aggressive, often killing and eating their mates. Many are eyeless, though some may have simple eyes that can detect light and darkness.

Scolopendra sp.
The above is a Scolopendra sp. which can grow to over 15cm long. These large centipedes are known to feed on smaller animals such as insects, lizards and even mice.

Black Centipede (Otostigmus sp.)
This black centipede is probably an Otostigmus sp. It was found under a rock, and the female was noted to provide parental care for the eggs, coiling around its eggs.

B) Order Scutigeromorpha

Members of this order are often called house centipedes or cave centipedes, as they are often seen indoor or in caves. They have a pair of long antennae, 15 pairs of very long legs, and are the only group of centipedes with large compound eyes, and hence making them very fast hunters. Many species can give painful bites.

Cave Centipede (Thereuopoda longicornis)
This cave centipede, Thereuopoda longicornis, is usually seen in the forest in Singapore. This is the only species of scutigeromorph centipede that has been recorded from here so far.

Cave Centipede (Thereuopoda longicornis) feeding on spider
The above photo features a cave centipede feeding on a spider.

C) Order Geophilomorpha

Members of the order are usually very long and slender, with at least 35 body segments. The legs are short, as these eyeless centipedes are adapted for burrowing. They have weak mandibles, and typically feed on small, soft-bodied invertebrates.

The above features an unidentified geophilomorph centipede that was found on a fallen log at night.

  • Bartlett, T. & J. VanDyk. 2003. BugGuide. Retrieved May 24, 2013,
  • Burnie, D. 2001. Animal. London: Dorling Kindersley. 624 pp.
  • McGavin, G. 2000. Dorling Kindersley Handbooks: Insects, spiders and other terrestrial arthropods. London: Dorling Kindersley. 255 pp
  • Ng, P. K .L., R.T. Corlett & H.T.W. Tan (eds.). 2011. Singapore Biodiversity: An Encyclopedia of the Natural Environment and Sustainable Development. Singapore: Editions Didier Millet. 552 pp.

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