The moulting process of the spiny lobster Panulirus homarus in the laboratory
was observed and described. In this speceis, a lobster approaching ecdysis can
be identified, almost 48 hours before, by the presence of a longitudinal
decalcified resorptive line along the branchiostegites. Under normal
conditions, the lobster completes ecdysis within 8-10 hours after the initiation
of the moulting process. The active phase of ecdysis is completed within 3-
4 minutes. Initially, the lobster withdraws the thorax gradually from the old
exoskeleton and finally sheds the abdominal part of it by strong flapping of
the tail. The lobster moulting on a rough substratum completes ecdysis in
the upright position, whereas those moulting on a soft substratum rolls on to
one side while withdrawing the walking legs. The newly moulted lobster
regains mobility within a few seconds and avoids contact with other lobsters
until the new exoskeleton is sufficiently hardened
