Invertebrates are animals that don’t have a spine. Land (or terrestrial) invertebrates include animals like insects and worms.
The most common animals in Antarctica are nematode worms, water bears (tardigrades), wheel-animals (rotifers), springtails and mites.
Beetles and flies are the most species-rich insect groups on the Southern Ocean islands.
Mites and springtails reach densities of several thousand individuals per square meter on maritime Antarctic and sub-Antarctic islands.
Earthworms and insects are responsible for most of the nutrient release from dead plant material in the sub-Antarctic.
Many invertebrates in the Antarctic can survive subzero temperatures without freezing. Many on the sub-Antarctic islands can freeze without dying.
On the Antarctic continent, water is one of the most important environmental factors in the distribution and abundance of invertebrates.
The most significant effects of climate change for invertebrates are temperature changes. This is because changes in temperature will effect water availability.
On the Southern Ocean islands, the most significant threats to terrestrial invertebrates are alien, invasive species. These include mice, rats, and predatory beetles.