The female carries 20–200 eggs under the side flaps of her abdomen, where they take 3–4 months to hatch. Over this time, male sperm production corresponds with females' reproductivity. Once hatched, juvenile koura cling to their mother's abdomen using their pincers to attach until they have reached a length of .
The female koura harbors eggs beneath her abdominal appendages for 3–4 months prior to hatching. Simultaneously, the male's sperm production is coordinated with the female's reproductive potential. Young koura remain attached to their mother's body using their pincers until they have grown to a certain length.