Mesofauna – Collembola
Collembola are small (0.12 – 17 mm) wingless hexapods commonly known as ‘springtails’. The scientific name, Collembola, derives from the Greek words kolla (meaning ‘glue’) and embolon (meaning ‘piston’) and was initially proposed in reference to the ventral tube (collophore), which plays an important role in their fluid and electrolyte balance and may also serve as a ‘glue piston’ for adhering to smooth surfaces or for grooming. Another characteristic, albeit not always present, gives them their common name: the forked springing organ or ‘furca’. This is held by a special catch mechanism on the ventral side of their abdomen which, when released, acts as a spring that can propel them, within seconds, several times the length of their body.
Collembola belong to the phylum Arthropoda. They are part of the class Entognatha that, together with the class Insecta, form the subphylum Hexapoda. They are classified into four orders: the Entomobryomorpha and Poduromorpha, with a more or less elongated body shape, and Symphypleona and Neelipleona, which are spherical in shape.
Collembola vary in their habitat preferences. Entomobryomorpha and Symphypleona are mainly epiedaphic, living in surface litter and emergent vegetation, and are fast movers and good jumpers, whereas the slow-moving Poduromorpha and Neelipleona are mainly within -soil dwellers (euedaphic). Most Collembola feed on fungal hyphae and spores, bacteria and decaying plant material. However, some species are predators, feeding on nematodes or on other Collembola and their eggs. Ecologically, they are not as important as earthworms in decomposition processes, but are still responsible for up to 30 % of total soil invertebrate respiration, depending on the habitat.
Diversity, abundance and biomass
There are around 8 500 described species, which are found in a great variety of habitats, from Antarctica and the Subantarctic Islands to rainforests, warm beaches and deserts. As well as being widespread, they are the most abundant hexapods in the world, and an average square metre of soil in a temperate grassland or a woodland can yield as many as 40 000 individuals.
Generally, habitats may support anything from two to 30 different collembolan species. However, in the tropics, up to 150 species can be found if species present in epiphytes (plants living in trees) are taken into account
Ref: A Global Atlas of Soil Biodiversity p 52