The term invertebrates covers all animals without backbones - in other words a huge range of different organisms from sponges and jellyfish to the arthropods ('joined limbs') which include what are probably the most familiar invertebrates such as insects and crustaceans. Insects are the best studied of the invertebrates in Shetland, but there are still big gaps in our knowledge.
The best-known group of insects are the Lepidoptera (moths and butterflies), but some of the Diptera ('true flies') are reasonably well-known, especially hoverflies (the family Syrphidae). The bumblebees, which belong to the Hymenoptera (bees, wasps and ants) have also received quite a lot of attention, while the Odonata (dragonflies and damselflies) are a group with just a few species in Shetland.
More will hopefully be added in the future.