In Crustacea, the neuroendocrine X-organ and
sinus gland complex in the eyestalk has long been
known to play an important role in the regulation of
molting and female reproduction (see reviews1–4).
The roles of the X-organ-sinus gland complex
were originally demonstrated by eyestalk ablation
experiments in the early works of Zeleny,5
Smith6 and Panouse.7 As eyestalk ablation caused
the stimulation of molting and female reproduction,
the existence of inhibiting factors in the
eyestalk was postulated. In recent studies, these
inhibiting factors were purified as neuropeptide