Photographs by Dr. Mayilvahanan.
Text by Joginder Singh.
He lifts just one leg at a time… taps gently on the silken threads and sends his vibrations to her. She’s wary and alert… he’s persistent. The tapping changes to a more gentle one as he stealthily moves closer. He is now tapping in striking range and offers her a silk wrapped gift. The ploy works! She accedes. He spins a few yarns of silk and temporarily immobilises her before mounting her. The rest is history. New spiders are in the making. Task accomplished, the worried male scampers away to safety, knowing that the moment his vibrations hit the wrong chord she will confuse him for any other insect… and make him her next meal.
1. Orb spider (Family Araenidae):
Exquisite beauty, born of function, radiates outward in concentric lines. Spiders locate their prey by picking up vibrations when victims struggle to break free from their sticky prison. Prey may be consumed immediately... or immobilised for future consumption.
Nothing like ’em
Spiders belong to a class of animals called ‘Arachnids’, which includes scorpions, mites, sun or ‘wind’ spiders and harvestmen or daddy longlegs. Of them all, the spiders, which belong to the order ‘Araneida’ are the largest group, numbering around 35,000 known species.
Spiders are not insects. They are Arachnids, which are identified by the fact that their bodies are divided into two parts. The cephalothorax or prosma is the front portion of the abdomen. The opisthoma is the hind portion. By contrast insect bodies have three segments.
Spiders are unique in several other ways. They have six to eight eyes, no wings and eight legs (insects have six). Instead of antennae, spiders have pedipalps. And at birth young spiders are virtual replicas of their parents, just smaller.
2. Fishing Spiders/Water Spiders/Nursery Web Spiders (Family Pisauridae):
Master opportunists, some spiders have actually learned to walk on water, taking advantage of surface tension to reach and neutralise prey with one poisonous bite.
She gets on to a carefully selected branch and lifts her abdomen… the spinnerets shoot out a gossamer strand of silk… the wind carries it and anchors it on to the opposite branch… she pulls it to check if it’s taut… the drama begins! From the centre she drops a horizontal trailing line of silk and anchors it onto a suitable branch below. The framework complete, a few quick radials, like spokes of a wheel, are criss-crossed… she gets back to the centre and starts connecting the radials with foothold threads, going anti-clockwise till she can’t go any further. The web is still not quite complete because it is still non-sticky! Purposefully, she retraces her path… going back clockwise over the framework, trailing her sticky, insect-trapping line behind her, even as she eats the non-sticky one! Gradually, the spiral shortens. Carefully she leaves a small non-sticky portion at the hub on which she will sit patiently till prey enters the parlour. The famous orb web, that has fascinated humans for aeons, is complete. The process takes almost half an hour. The hunter is in position. The wait is on.
3. Funnel web spider (Family Agelenidae):
This is a sheet web, built under a rock. It ends in a tubular section. The spider stays hidden in the funnel and emerges the moment it detects prey struggling on its web. The victim will be pulled into the tunnel from where escape is impossible.
Hunters on the loose
Though all spiders have the ability to release silk it isn’t mandatory that all will spin webs. And the designs of those that do vary considerably in shape and size depending on the species. All spiders, however, are predators, whose hunting methods vary according to the species. There are those, like the spitting spider, that ensnare their prey by spewing out zig-zag threads of gum from their fangs; others that dangle a front leg in water and pounce upon tiny fish that venture close enough; and still more that make tunnels in the ground complete with trapdoors behind which they hide. Some even hunt underwater, while others can walk on the surface . Charles Darwin called it ‘Survival of the Fittest’. As a confirmed spider-watcher I know precisely what he meant.
4. Green lynx spider Peucetia viridana. (Family Oxyopidae):
These beautiful, diurnal spiders do not build webs, preferring to ambush their prey. The female hides her egg sacs on the underside of leaves, and will stand guard till they incubate. As can be seen, they often lie in wait for insects that visit flowers in search of nectar.
The multiplication game
The fertilised female spider, generally much larger in size than her male counterpart, will, a week or more after the coupling, lay a clutch of eggs in a silken sac woven specifically for the purpose. The number of eggs in the batch may vary from one or two to over 10,000, depending on the species. The egg sacs are either concealed and protected, or carried around attached to the mother’s abdomen. When the eggs hatch the spiderlings will emerge, staying practically motionless. As soon as they are oriented they will start the deadly business of feeding. As they grow older, the young ones will moult and discard their exoskeleton, a process that will continue throughout their lives.
5. Giant wood spider Nephila maculata:
This spider probably constructs the largest orb webs in the world, often stretching between trees right across forest paths. Males (two potential mates visible here) are much smaller than females and must approach them with great caution, using postures and drumming signals on the web. If rejected, males will retreat quickly, or may otherwise be eaten. Successful males will die within days of mating.
Some spiders feel the urge to get away… get on to a high branch… lift their abdomens ... trail out gossamer strands till the wind catches them and lifts them high. Organic wind-powered predators, the spiders are actually airborne! They will go wherever the wind blows. When they are let down, they will clamber up the nearest suitable perch and hunt for what food they can get. Once sated they will again lift their abdomens, shoot out a gossamer strand of silk… and fly!
Welcome to the wonderful world of spiders, nature’s original web masters.
6. Harvestmen or Daddy longlegs (Family Pholcidae):
While most spiders are solitary, these are social creatures and can be seen in fields in clumps of hundreds. Sedentary by nature, they are most often spotted under rocks and in dark places. The webs are either sheet-like or irregular. Females carry the egg sacs around to protect them.
Misunderstood and feared, spiders evoke little sympathy from most humans. They are, however, among nature’s most fascinating subjects. That beauty is inherent in the world of spiders can be seen from these images. And, as anyone who has studied them will confirm, they are as good an example of evolutionary perfection as anyone might ask for.
7. Wolf spider (Family Lycosidae):
Hidden in a silken funnel in the root system of a jackfruit tree, this medium-sized, drab looking spider awaits prey. Females carry their egg sacs in their spinnerets and carry their young on their backs for some time after they are born. Wolf spiders that belong to the genera Hippasa and Sosippus build funnel webs, others stalk their prey, earning them their name.
8. Spiny orb-weaver Gasteracantha sp.:
An orb weaver, this ‘armour-plated’ spider may sport spikes twice the length of its abdomen. It hunts in low shrubs and bushes.
Photographs by Dr. Mayilvahanan. Text by Joginder Singh. Sanctuary Asia Vol XX No. 3, June 2000.