Comparative development of cyphonautes and coronates

In-depth comparison of cyphonautes and coronates body patterning.

Early development

  • How different are the fate maps between the two types of larvae?
  • What are the key differences in the regulation of development that might be related to the differing morphology?


  • Which tissues originate which adult structures and is there any variation when comparing cyphonautes and coronates?
  • Which organs will form the cystid in different larvae?
  • Which tissues form the polypide rudiment in different larvae?

Questions notes

Develop a method to discover which larval type is ancestral. How? Only six genera have cyphonautes and they are considered to be “more primitive”, Cheilostomes and Ctenostomes. Can the comparison of the early development patterning and gene expression between cyphonautes and coronates reveal any key regulatory mechanisms? Can I use cooption events to solve this? Absence of spiral cleavage in all bryozoans might indicate an early feature of the group. Brooding could have disrupted early development, or in a Buss (or Metchnikoff?) sense, allowed variation to appear. If first bryozoans were brooders, then are cyphonautes derived/specialized larvae? Does having similar cleavage mean something? Would cyphonautes have evolved by paedomorphosis of coronate-like larvae? Or vice-versa?

Extra: Cyphonautes morphogenesis

  • How cyphonautes got flattened?