Abstract. 1. Using a recently created database representing the joint effort of around 100 invertebrate taxonomists, this study uses the information on 52 arthropoda and 27 mollusca species that are endangered and critically endangered to examine to what extent invertebrate species are represented in existing Spanish protected areas.
2. As distribution information is available at a 100 km2 resolution, we consider different area thresholds to judge cells as being protected.
3. Approximately 19% of the area represented by the grid cells with observed occurrences rates as extant protected reserves, and 36% is included within the Natura 2000 network.
4. If having 50% of the cell area as a Natura 2000 reserve is considered as sufficient to have effective protection, almost 68% of species and 32% of probable populations (contiguous cell groups) would be represented.
5. However, 77% of species and 94% of probable populations are not represented in the current protected reserves if we establish that at least 95% of each cell area should belong to a reserve to provide effective protection.
6. Thus, existing conservation strategies, which are based primarily on the protection of certain areas and vertebrate species, may be insufficient to ensure the conservation of invertebrate species.