Invertebrates are animals without backbones, which includes insects, spiders, snails, and worms to name but a few.
Over 90% of the animal species known to science are invertebrates. They are found in all habitats including the driest deserts, the frozen Antarctic and the deepest oceans.
Invertebrates are ectotherms (i.e. cold blooded) and need to warm their bodies by absorbing heat from their surroundings.
Many invertebrates undergo a degree of change or metamorphosis during their life cycles, resulting in the young having a very different appearance to the adult forms. Most invertebrates either live permanently in water, or spend at least some part of their life cycle in water.
Many invertebrates play a critical role in the functioning of ecosystems (e.g. pollination, recycling) and are important indicators of ecosystem health and change.
The colossal squid is the largest invertebrate on Earth, and can grow to 13 metres in length and weigh over 500 kilograms.