The southwest monsoon has taken Mumbai by storm. The added moisture has allowed dormant seeds to germinate and hiding fish and crabs to emerge. In the urban milieu, earthworms have emerged in our bathrooms, from unimaginable pores between our tiles. Our team here started farming activities last week, by preparing the soil in our planters. The plan is to sow some corn now and get a few hours of gardening every week. These sessions give me a chance to observe the varied creatures that emerge out of our soil — ants, beetles, snails, caterpillars, millipedes and centipedes.
Like most other children, I wasn’t too clear about the difference between a centipede and a millipede. On reading up, I realised the Latin origin of the name, wherein centi meant hundred and pes or pedis meant legs. It was much later that I realised that the name centipede itself was a misnomer, as they actually bore anywhere between 30 to 354 legs. Although centipedes and millipedes may seem alike to the casual observer, they can be easily differentiated by the arrangement of legs. Centipedes have a single pair of legs on each body segment, whereas millipedes have two pairs per segment. Further, centipedes always have an odd number of pairs.
The head of centipedes have a pair of long and sensitive antennae which they use to detect prey. But, the sure way to identify a centipede is to observe its first pair of legs which are modified into a pair of fangs or forcipules, connected to venom glands. The sharp venomous fangs not only hold the prey but also deliver venom to immobilise the victims, viz. cockroaches, flies, worms, spiders, fledglings, rats, bats and other small mammals. Centipedes are ecologically very important as the largest terrestrial invertebrate predators, growing up to 30 cm in case of some Scoleopendras or Tiger Centipedes.
Centipedes are highly adaptable creatures found in a wide array of terrestrial habitats ranging from tropical rainforests to deserts and even beyond in the Arctic region. They lack the waxy cuticle of most arthropods and hence require a moist microhabitat to keep their body hydrated. Thus, it's not uncommon to find them in stacks of wood, under leaf litter, in crevices of rocks or tree bark and other organic matter (compost) which is dark and moist. I've been shocked to see centipedes swim out of a western commode or disappear inside a sink or swimming pool. Once, around midnight, I even saw a 13 cm centipede hunt geckos on Dadar Railway Station. This nocturnal hunter obviously caused some panic as some species are known to deliver painful, but non-fatal bites when provoked by humans or domesticated animals.
Worldwide, an estimated 8,000 species of centipedes are believed to exist, of which only 3,000 have been described, giving ample scope for Myriapod taxonomists to describe new species. Most centipedes are fossorial (underground) breeders, with females laying between 35 and 40 eggs during spring-summer months. The eight-legged larvae go through six instars (shedding of outer skeleton) to adulthood and may live up to three years.
Excessive concretization and extermination by humans are the biggest threats to their survival. Locally, the myth that centipedes enter human ears to lay eggs in the brain and their consumption by the Chinese has pushed this multi-legged hunter to the brink of disappearance.
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