How a tiny and strange marine animal produces unlimited eggs and sperm over its lifetime

A little-known ocean-dwelling creature most commonly found growing on dead hermit crab shells may sound like an unlikely study subject for researchers, but this animal has a rare ability—it can make eggs and sperm for the duration of its lifetime. This animal, called Hydractinia, does so because it produces germ cells, which are precursors to eggs and sperm, nonstop throughout its life. Studying this unique ability could provide insight into the development of human reproductive system and the formation of reproductive-based conditions and diseases in humans.