Egg development in a littoral pycnogonidNymphon gracile

Aspects of the reproductive biology ofNymphon gracile (Leach) are examined. The eggs develop between August and February, when they are passed to the ovigerous legs of the male. The process of vitellogenesis closely resembles that of annelids andLimulus polyphemus, in which the majority of the yolk is synthesised intra-oöcytecally, with only a small extra-oöcytic contribution.