Silken Feet: A Tarantula Feat!

On Friday, I published a small article on the Bombardier Beetle and its amazing defence system. Today's leggy protagonist, the Tarantula, reveals another incredible result of Evolution's constant tinkering to improve the everyday functions of its family of creatures.

As my regular readers will know, I spent many years living in the desert of South Baja California, Mexico. There, I encountered many arachnids, the Mexican Flame-Knee Tarantula the most unforgettable.

Little was I to know that it would be this gorgeous arachnid which would recently reveal another staggering fact to biologists: this tarantula - and many others of the species, including many from the whole spider family - can actually extrude silk from their feet!

Yes, worth reading again: not just from the well-known method, by means of their spinnerets, which is how web-building spiders make their unique insect traps and homes, but directly through their feet. In the case of the heavy-bodied tarantulas, which, unlike the lighter spiders, might be injured or even killed by a fall, the ability is more pronounced.

The study which has revealed this new and gripping secret from the world of spiders also brought to light that Tarantulas - archaic arachnids - have demonstrated that the two types of silk they produce are dissimilar in size, strength and stickiness; that from the feet being the finer and possessing more gripping power.

More modern spiders, in fact, produce several more distinct silks for varying uses.

These tests are said to be reported in the "Journal of Experimental Biology," a publication I hope to become associated with shortly.

In the experiments leading to the remarkable conclusions, tarantulas (Two Chilean Rose and the Flame Knee, ("Fluffy" a pet of Dr Rind, the investigator!) were put into a glass box. The box was then inverted and gently shaken, causing the spiders to slide down the sides. Minute examination of their unsteady route down to the "floor" again showed many fine lines of silk attached to the glass which could have only come from the creature’s feet. All arachnids have hairs on their feet and the silk may have passed through these hairs to become stuck onto the glass.

Examinations were also made of old skins of Fluffy's, shed during her moults as she grew, which may have produced some further evidence of the silk-making process. The investigation is still proceeding.

Many people keep pet taras and I have written other hubs about the arachnids. Basically, they can be divided into "Old World," and "New World" species, those from the old world the more venomous. (Asia, etc.). Yet those from the new world, (such as Mexico, etc.) have a greater capacity to "throw" urticating hairs which can blind in extreme cases and will cause irritation in lesser attacks.

One owner of a Chilean Rose Tarantula was cleaning her cage when she decided she was angry at him for some obscure reason (see notes). She shuffled up to within about 6 inches of his face; rubbed her forelegs together and released a fine mist of these tiny hairs which entered his eye nearest to the spider. After a short time, his eye began to itch severely and become bloodshot. He had some idea of what had happened and went to hospital.

There, eye doctors examining him with microscopes found many of the minute hairs sticking out of his eye, or, because of the barbs on them, working their way down into his eye! They could do nothing because some were unreachable without surgery and those they could still reach were too fine to be grasped with tweezers - even using the microscope. He was given medication and told they would hopefully dissolve after some time, which condemned him to some months of suffering. Not a thing you want to happen, it would be less worrying to be bitten. One can only speculate as to whether these hairs will eventually reach the brain!

Evolution doesn't just fashion its defences to scare-off predators; in many instances, they carry on to blind or even kill them, which serves to cut down on the danger.

Note: Although pet owners vigorously deny the charge, reptiles, arachnids and insects, etc., have no capacity for affection or any kind of sentiment like this. They may get used to their owners and even sit placidly on their hands or laps, but they don’t have love on their minds.

Of course, that may be enough for you: the illusion of love may suffice (look at prostitution!). But if your pet mamba, spider or scorpion has a bad scale day, watch out! You might learn the hard way that illusions can soon be dispelled.

On a more pragmatic note, if you do keep taras, always wear protective glasses when cleaning or playing with them: these hairs are really nasty and have actually blinded people...I recommend a mini-Schnauzer as a pet!