Invertebrates are animals without backbones and make up the great majority of animal life, with 40,000 species in Britain alone and many millions on Earth.
From Shetland to Lands End, from the Arctic to the Tropics, nearly all animals are invertebrates, and it is the same in the seas of Britain and the rest of the world.
A green lacewing (Chrysopa perla)
© Roger Key
To most people, an animal is a mammal, bird, reptile, amphibian or fish. These are all vertebrates, since they have a spine composed of vertebrae. Invertebrates are also animals, generally with a heart, nervous system, senses and mobility that have parallels with ourselves. What's different is that they lack a spine and vertebrae.
The diversity and specialisation of invertebrates is truly staggering. In many cases they are able to transform themselves from one thing into something entirely different. For instance, once a mouse, always a mouse. Yet a caterpillar is able to completely reconstruct itself in a pupa to become a beautiful flying butterfly - two completely different animals for the price of one. And for all the skills of a bird in making a nest, an orb web spider surely rivals the finest engineer in its delicate structural design. All you have to do is look, and you will see that the world of tiny creatures is full of beauty, fascination and extraordinary happenings.
The majority of Britain's invertebrates are insects. We have about 27,000 species. Some are as large as a mouse and some are conspicuously colourful. Many thousands are tiny and hide away from sight, though even these can be extraordinarily beautiful when examined close-up and often have incredible life stories.
Stone centipede - moulting
(Lithobius forficatus) © Roger Key
Our insects include beetles, flies, bees, wasps and ants, true bugs, butterflies and moths, mayflies, dragonflies and grasshoppers, in fact 25 totally different sorts (Orders). Related to insects are other types of animals with jointed limbs (known as arthropods), such as spiders, crayfish, water fleas, woodlice and millipedes. We have well over 3,000 species of arthropod in Britain.
Additionally there are other invertebrates with totally different types of bodies, such as snails, worms and sponges. This includes at least 13 major types of animals on land and in freshwater, with over 3,000 species, but in the sea there are even more types (Phyla).
If there are so many species, does it matter if some are lost?
Yes, it does. They all have a special place in the web of life and they cannot be replaced once lost. A lot of them may yet be recognised as of benefit to man, in pest control, pollination of crops or special chemicals for medicine. And most have incredible life stories yet to be told. We literally don't know what we are on the brink of missing.
It is essential that when we speak of biodiversity we include all animal life. This wealth of life forms is an essential part of the very substance of the web of life, yet humans are blindly squandering this heritage. On a world scale huge numbers of species have been lost to habitat destruction, and the trend continues. At this rate millions of species will be lost unknown.
Banded demoiselle (Calopteryx splendens) © Roger Key
Even in Britain, which is in the top league of conservation active countries, many species are in decline and extinctions are mounting.
Why are we so fixated with reaching distant stars, when there's such an extraordinary micro-universe beneath our feet?
There continues to be public excitement in proving the existence of life beyond our planet, and billions of pounds are spent each year on sending probes into space. Yet we have not even learnt to appreciate the life forms on planet Earth. Without a concern for smaller animal life, how can we claim to be preserving our precious world to future generations?
Buglife is rising to the challenge, so please join us in focusing conservation effort onto the world's smallest, most important but most neglected inhabitants.