Life of a Crustacean Larva 

All crustaceans share some characteristic developmental stages and processes...

• embryos undergo modified SPIRAL CLEAVAGE while passing through a blastula stage.  Most crustaceans divide holoblastically, meaning the cleavage goes all the way through the yolk.  

• they have TELOBLASTS, stem cells that produce ectoderm and mesoderm for posterior thorax and everything behind it, including telson. The anterior structures are made from the germinal disc.

• they all pass through larval stage called NAUPLIUS

  • nauplius, or ZOEA, larva can be free-living (when eggs have little yolk).  

  • this stage can also be passed within the egg during embryonic development (in yolky species)

• eggs are mostly CENTROLECITHAL, meaning the yolk is dense in the center of the egg and the cytoplasm exists on the outside.  

• knowledge of crustacean fertilization is limited due to

  • eggs’ opacity

  • fertilization existing within the female

    • immediately after egg is laid, the sperm reach the egg and form the first polar body.