Lowlife

A couple of months ago I stacked some old broken fence panels on the soil at the bottom of the garden and when I moved them today I found they were sheltering all sorts of interesting soil invertebrates.Two species are illustrated below.

This wonderfully articulated centipede was living in the soil under the wood. Judging by the number of pairs of legs, I think it must be Haplophilus subterraneus, which has between 77 and 83 pairs. The books say that it sometimes glows in the dark if it's disturbed at night, so I might go back and have another look later tonight.

These are springtails - possibly Folsomia candida. There were thousands of them, probably eating fungi that were growing on the decaying wood panels. 

Springtails are noted for their ability to hurl themselves into the air using a spring-loaded appendage called a furcula under their tail. If you've never seen a springtail jump, take a look at this clip from David Attenborough's Life in the Undergrowth


For some more, higher magnification images of springtails, click here

For some detailed information on the Collembola - the subclass of six-legged invertebrates to which springtails belong, click here

Take a look at Steve Hopkin's wonderful web site for ID photos of springtail species and for some truly stunning pictures of these tiny animals take a look at this Flickr gallery belonging to Eddie the Bug Man (Eddie Nurcombe)

A single-animal stampede ....

I started digging the vegetable garden this afternoon but didn't get very far because I found this fine specimen of the centipede Haplophilus subterraneus curled up under a plant root. This is probably the longest garden species in Britain, although you wouldn't think so when it's coiled up in a ball like this.

When it unwound itself and began to run I'd estimate that it must have been close to three inches long. Ground-living centipedes have an aversion to light even though they have no eyes and this one instantly headed for a dark crevice (that's the head at the bottom). The last pair of legs are modified into touch-sensitive antennae-like structures that provide the animal with some information about what's going on way back in that final segment.

It's difficult to photograph these because they only come to rest when they are in contact with something above and below their body - when they are in a tunnel or under a stone for example. Despite their name, no centipede has exactly 100 legs. The books say this one has 83 pairs (seems reasonable, it was moving too fast to count them), so when it runs that's 166 feet stampeding - a wonderful feat of coordinating feet movements.

Santapede

This centipede Lithobius forficatus broke cover and raced across the floor when I was shifting some flower pots around in our conservatory in Christmas Day. Centipedes lose water very easily through their exoskeleton, so tend to spend much of their time in crevices and prefer to rest in places where there is something solid above and below them - under a stone (or flowerpot) for example, where their flattened shape allows them to crawl into small spaces. Providing this one with a piece of wet paper to rest on gave it an opportunity to top up its water supply and allowed me just enough time to photograph it before it raced for cover.

It always comes as a bit of a disappointment to learn that there are no centipedes with 100 legs and L.forficatus has a mere 15 pairs. The hind two pairs are much longer than the others and have more of a sensory than a locomotory role, because when the animals wedge themselves in crevices they often have to reverse out - I guess you can think of those long hind legs as the invertebrate equivalent of parking sensors fitted to the rear of expensive cars. For these beautifully articulated animals, reversing out of a narrow gap must be rather like reversing a car with fifteen trailers attached.

Centipedes have very poor eyesight so rely heavily on their antennae for locating food and monitoring their surroundings by touch and smell. Understandably, they take great care of their antennae and this one is drawing the left antenna through its jaws to clean it. The jaws are located out of sight under the head and are separate from those lethal venomous fangs on each side of the head.


Centipedes have one pair of legs per segment, while millipedes have two, but L.forficatus hatches from the egg with only seven segments and seven pairs of legs - additions are made with each moult, until a full complement of 15 segments and pairs of legs is reached.