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.
Key Reproductive Features: gonochoric/gonochoristic/dioecious (sexes separate); simultaneous hermaphrodite; sexual ; fertilization (External , Internal ); ovoviviparous ; oviparous
Members of the Neomeniomorpha sometimes brood the eggs. However, most species release the gametes without further parental care.
Parental Investment: pre-fertilization (Provisioning); pre-hatching/birth (Provisioning, Protecting)
- Brusca, R., G. Brusca. 2003. Invertebrates. Sunderland, Massachusetts: Sinauer Associates, Inc..
- Ponder, W., M. Shea, D. Beechey, R. McBain. 2000. "Aplacophora (the spicule worms)" (On-line). Shelled Marine Mollusks of Temperate Australia. Accessed February 07, 2005 at http://www.danceweb.com.au/marine/data/majgrps.htm#apla.