From Page 1 One behavior we watch for very carefully on our line is the appearance of mating behavior.
Copulation means the animal has entered the reproductive phase that soon leads to senescence.
Thus, once mating behavior is observed in a cohort in the facility we know that cohort has ended its useful life on the line. Lynne is studying the development of the capability to release egg laying hormone. Sexual behavior and egg laying functionally define sexual maturation in Aplysia. Yet Aplysia are considered adults much earlier in development when the reproductive system is newly formed, at stage 13, about 120 days after hatching. An important developmental feature of this stage is the appearance of the bag cell clusters on the abdominal ganglion.