Caribbean hermit crab right claw and is purple in color. Female land hermit crabs release fertilized eggs into the ocean. The spawning (called "washing" in the English-speaking Caribbean) occurs on certain nights, usually around August. This species is one of the two land hermit crabs commonly sold in the United States as a pet, the other being the Ecuadorian hermit crab. "C. clypeatus" has been confirmed to live as long as 12 years, and some crab owners have claimed to have crabs live up to 40 years. Caribbean hermit crab The Caribbean hermit crab, Coenobita clypeatus, also known as the soldier crab, the
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