Some observations on the biology of Anurida maritima (Guérin), (collembola)

Abstract

A study about the function of the "nests" of Anurida maritima (Guér.) in the vertical clay-walls of some creeks has been carried out. In these nests the animals seek refuge from the incoming tide. They clump together in cavities, which are filled with air during high water. At low tide part of the population wanders over the salt marshes in search of food. Among these animals the females prevail. Another part of the population however, remains in the nests, in which they moult. In some of these nests mainly sexually mature animals can be found, which meet there to deposite the eggs. The eggs hibernate. This is considered to be a diapause. They hatch in April. Weather conditions appeared to have a marked effect upon the animals. Three reactions may be distinguished: 1. During sunshine little exchange of animals takes place between nests and marshes. 2. Disappearance of the sun, resulting in a darkening of the sky and a lowering of the temperature induces an increased activity. 3. Rainfall induces as a result of the rising moisture content of the marshes an increase of the activity in the direction of the nests, causing a decrease of the density on the marsh. 4. The animals hide in the nests during unfavourable weather conditions. © 1966 Springer-Verlag.