Males paste a sperm-filled spermatophore onto the genital opening (GONOPORE) of a soft-shelled female.  Then, as the eggs are passed through the female’s gonopore, they are fertilized by this mass of sperm, where they stick to the pleopods until further development.  

 

Female ghost shrimp reach sexual maturity after 2 to 3 years and will be gravid, broodings eggs, for 5 to 6 weeks before the larvae hatch.  As they are quite small for crustaceans, for females egg-laying is extremely energy intensive--they will dedicate up to 40% of their body weight to produce these eggs.  They carry eggs in June and July.  One study in Willapa Bay, Washington measured an average fecundity of 3,900 eggs in females (Dumbald).

 

Surprisingly, immediately after a batch of larvae have hatched from the female, she will molt and can ovulate once again within the same day.