Welsh Journals

Spiders of the Gower Sand Dunes by LYNWEN OWEN The SAND DUNES AROUND Gower are rich in wild life and not least, but overlooked by many, is the world of the spider. The habits of these little creatures are of absorbing interest once the observer has overcome his first instinctive repugnance. Spiders are invertebrates (animals without a backbone). They differ from insects by having eight legs instead of six. The body of the spider is divided by a waist into an anterior hard cephalo- thorax (head and chest) and a posterior soft abdomen. At the front of the cephalothorax are two to eight eyes, a pair of palps (feelers) and a pair of large poison fangs, with which the spider bites and kills its prey. Most British spiders cannot bite human beings and even the bite of the so-called poisonous spiders of abroad is not fatal. A spider cannot swallow solid food but sucks away the juices of its prey-hence the dried-up skeletons of insects found on a spider's web. At the hind end of the spider are usually three pairs of spinnerets. The silk thread emerges through as many as a hundred tiny apertures in these structures. The eight jointed legs are quite hairy and terminate in two to three claws. Most people think that spiders are black ominous creatures but closer examination will usually reveal a very definite and often decorative pattern. Male spiders are often smaller and thinner than the females, and the palps terminate in bulb-like structures which store the sperm. The male inserts these into the female's genitals to fertilise the eggs. Most spiders have an elaborate courtship. The male has to court and coax the more fierce female to mate. In hunting-spiders this is often in the form of an elaborate dance to display his coloured body. In web-building spiders it is usually in the form of a morse code of vibrations and tappings on the web. It used to be thought that most male spiders were eaten by the females after mating, but this is not generally true. Most people when walking along the bare sand of the Gower dunes do not realise that there are spiders running around beneath them. This is because of their remarkable camouflage, i.e. their colour and markings blend so well with that of the sand that they are almost invisible when still. It is only their movement that catches one's eye. Most common on the bare sand is the WOLF SPIDER Arctosa perita (8 mm. long). This is a straw-coloured spider with diffuse black, brown and orange markings, and two pairs of white oval patches on the abdomen. Wolf Spiders are nomadic, active, ground-living spiders that hunt and pursue their prey with great