Ecuadorian hermit crab few months, but species such as "Coenobita clypeatus" have a 23-year lifespan if properly treated and some have lived longer than 32 years. Similarly Ecuadorian hermit crabs have been known to live to over 30 years. In general, and despite their moniker, hermit crabs are social animals that do best in groups. They also require a temperature and humidity-controlled environment (ideally approximately 80% humidity or above and 75-85F), and adequate substrate to allow them to bury themselves while molting. Ecuadorian hermit crab The Ecuadorian hermit crab (Coenobita compressus) also known as the Pacific hermit crab is a species of land
History of manifolds and varieties History of manifolds and varieties The study of manifolds combines many important areas of mathematics: it generalizes concepts such as curves and surfaces as well as ideas from linear algebra and topology. Certain special classes of manifolds also have additional algebraic structure; they may behave like groups, for instance. In that case, they are called Lie Groups. Alternatively, they may be described by polynomial equations, in which case they are called algebraic varieties, and if they additionally carry a group structure, they are called algebraic groups. The term "manifold" comes from German "Mannigfaltigkeit," by Riemann. In English, "manifold" refers to