Common Egg Cowrie

About

The common egg cowrie (Ovula ovum) is one of those invertebrates that stops people in their tracks at the fish store. The shell itself is a smooth, porcelain-white oval, but what makes this animal so visually arresting is its mantle. The fleshy tissue that can extend out to cover much of the shell in deep black or dark brown, often dotted with small white or pale spots. It is a genuinely striking contrast that looks almost unreal. Native to the Indo-Pacific, this species lives in shallow coastal waters down to around 20 meters, typically found crawling across reef structure and rocky substrate. Despite the theatrical appearance, it is a peaceful animal that poses no threat to fish tankmates. That said, it is worth knowing that egg cowries feed on soft corals and related cnidarians in the wild, so placing one in a reef tank with prized soft coral colonies is a gamble most reefers would rather not take. A fish-only or FOWLR setup suits it much better. Care is relatively straightforward, making it accessible to hobbyists who are comfortable with basic marine water quality but want something a little different from the usual snail or hermit crab.