Invertebrates have no spinal column in contrast to the more widely known, informal group of vertebrates. Invertebrates also include the large phylum of arthropods, which can be subdivided further into groups such as insects, spiders, crustaceans and millipedes.
Shellfish, snails and nematodes are also invertebrates. Valid Red Lists are available for some of these groups. However, for the majority of the 48,000 invertebrate species and sub-species that occur in Germany, no threat assessment is yet available.