Aplacophorans may be monoecious or dioecious with single or paired gonads. All discharge gametes through gonopericardial ducts into the pericardial (heart) chamber. Gametes then pass through gametoducts to the mantle cavity where they are then released outside the body. Animals in the Chaetodermomorpha have external fertilization while those in Neomeniomorpha are internally fertilized, and sometimes even brooded. (Brusca and Brusca, 2003; Ponder et al., 2000)

   

Members of the Neomeniomorpha sometimes brood the eggs. However, most species release the gametes without further parental care. (Ponder et al., 2000)