Volcano of classifying magmatic volcanoes is by their frequency of eruption, with those that erupt regularly called active, those that have erupted in historical times but are now quiet called dormant or inactive, and those that have not erupted in historical times called extinct. However, these popular classifications—extinct in particular—are practically meaningless to scientists. They use classifications which refer to a particular volcano's formative and eruptive processes and resulting shapes. There is no consensus among volcanologists on how to define an "active" volcano. The lifespan of a volcano can vary from months to several million years, making such a distinction sometimes
Extinct in the wild among aquarists for some time, but hobbyist stocks have declined quite a lot more recently, placing its survival in jeopardy. However, the ultimate purpose of preserving biodiversity is to maintain ecological function. When a species exists only in captivity, it is ecologically extinct. Reintroduction is the deliberate release of species into the wild, from captivity or relocated from other areas where the species survives. This may be an option for certain species that are endangered or extinct in the wild. However, it may be difficult to reintroduce EW species into the wild, even if their natural habitats were restored, because