sentence: Nautiluses are sexually dimorphic and reproduce by laying eggs.
sentences_after: Females spawn once per year and regenerate their gonads, making nautiluses the only cephalopods to repeat reproduction. The lifespan of nautiluses is about 20 years, which is exceptionally long for a cephalopod.
concept_name: nautilus
headings: Nautilus Natural history Reproduction and lifespan
categories: Cephalopods Living fossils