Invertebrates

Invertebrates are all animals with no backbone:

• insects – e.g. butterflies, moths, beetles
• spiders
• worms
• crustaceans – e.g. crabs, lobsters
• molluscs – e.g. slugs, snails, mussels

Invertebrates make up around 98% of animal life – though no one knows exactly how many species there are. Invertebrates inhabit our land, rivers, lochs and seas. Between land and freshwater alone, Scotland may be home to some 50,000 species.

Some key habitats include:

• rivers – where freshwater pearl mussels occur in internationally important numbers
• Caledonian pinewoods – home to threatened species such as the pine hoverfly
• machair – where the great yellow bumble bee and northern colletes bee are found
• damp species-rich grassland, damp moorland and rush pastures in western Scotland – one of the last areas in Europe for the marsh fritillary butterfly

Ecosystem roles

Invertebrates are vitally important as they:

• turn natural waste into fertile soil
• pollinate crops and wild flowers
• are an essential food source for some fish and birds

Similarly, many smaller marine invertebrates, which occur in vast numbers, nourish fish and whale species from tiny sandeels to giant basking sharks.

Uses by people

Lobsters, crabs, langoustine and scallops are invertebrates of great importance to the Scottish economy. They provide a living for many people and a favourite food for many more of us.

Threats to invertebrates

Invertebrates are at risk from:

• habitat fragmentation and loss
• declines in habitat quality
• climate change
• pollution

Guidance

The following guidance on Assessing habitats for deadwood invertebrates is now available to download.
Guidance - Bumble bees - natural mortality
Read our guidance for planners and developers.