Dormancy is a suspension of the vital functions in an organism to overcome harsh environmental conditions, and sometimes can last for centuries. It is a widespread adaptation in many phyla, ranging from bacteria to vertebrates, and may exert a great influence on aquatic communities.

Contributors to this new book are leaders in the field of diapause studies, and many authors were participants at a recent workshop on diapause in aquatic invertebrates (Pallanza, Italy 2003). The book consists of two major parts, as indicated in its title: Phenomenology of diapause and significance of this adaptation in scientific and practical uses. Application to newly developing areas such as cultivation of live food, like rotifers or Artemia, in modern aquaculture is covered, as are aspects of diapause that promote the colonization of new environments by facilitating the passive transport of resting stages of invasive species. Creation of artificial ecosystems outside of the Earth s biosphere using dormant propagules becomes an actual possibility as humankind develops plans to colonize our nearest planets. Also, studies on the vertical distribution of resting stages in undisturbed sediment cores yield important ecological and evolutionary information useful in investigations of past environments.

Throughout the book properties of diapause and individual peculiarities of this ancient and well-developed adaptive phenomenon are regarded in evolutionarily distant groups such as Rotifers, Crustaceans and Insects."

Many authors of this new book were participants at the workshop on diapause in aquatic invertebrates (Pallanza, Italy 2003). The book consists of two major parts indicated in its title: Phenomenology of diapause and significance of this adaptation in scientific and practical uses. Cultivation of live food, like rotifers or Artemia is an expanding application of practical use of diapause in modern aquaculture. Diapause provides the advantage of promoting the colonization of new environments by facilitating the passive transport of the resting stages of invasive species. Creation of artificial ecosystems outside the Earth's biosphere with using dormancy becomes an actual possibility with the plans of humans to colonize our nearest planets. Studies on the vertical distribution of resting eggs in sediment cores yield important ecological information.

Diapause is an event of great ecological significance in the lives of a wide range of invertebrates. The underlying physiological and genetic mechanisms pose many intriguing questions and have important evolutionary implications. Some of the most dramatic examples of diapause are provided by crustaceans. Most branchiopods produce resting eggs that can withstand intense desiccation and extremes of temperature and pressure far beyond those to which they are ever subjected in nature. Furthermore they can remain in a dry condition, displaying no measurable metabolism, for many years. Such abilities enable them to inhabit infrequently-filled pools in arid regions. When the pools fill with water these dormant eggs hatch and give rise to animals that grow quickly to maturity and produce a new generation of resting eggs. There is every reason to believe that primitive branchiopods have employed diapause in this way since Palaeozoic times and that their abilities in this direction have played a key role in their continued success as freshwater animals.