The word "egg capsule" refers to the protective covering that encases an egg either before or after it is laid. There are several synonyms for this term, including egg sac, ovicapsule, and spawn capsule. The term "egg case" is also commonly used, particularly when referring to the capsules of certain species such as the praying mantis or the portly spider. The egg pouch is another term used to describe the casing that protects developing eggs in some aquatic creatures such as seahorses and pipefish. Regardless of the name used, these capsules serve a vital role in protecting and nurturing developing offspring until they are ready to hatch or be born.