Ecdysis in cockroach
Ecdysis
is the moulting or periodic loss of the outer cuticle of arthropods.It
is shed during growth and a new, larger covering is formed The remnants
of the old, empty exoskeleton are called exuviae.
After moulting, an arthropod is described as teneral, a callow; it is "fresh", pale and soft-bodied. Within one or two hours, the cuticle hardens and darkens following a tanning process similar to that of the tanning of leather. It is during this short phase that the animal expands, since growth is otherwise constrained by the rigidity of the exoskeleton. Growth of the limbs and other parts normally covered by hard exoskeleton is achieved by transfer of body fluids from soft parts before the new skin hardens. Some arthropods however, especially large insects with tracheal respiration, expand their new exoskeleton by swallowing or otherwise taking in air. The maturation of the structure and colouration of the new exoskeleton might take days or weeks in a long-lived insect; this can raise problems in trying to identify the species when a specimen has just recently undergone ecdysis.
Ecdysis may also enable damaged tissue and missing limbs to be regenerated or substantially re-formed, although this may only be complete over a series of moults, the stump being a little larger with each moult until it is of normal, or near normal size again.
I just could not get any pictures of the earlier stages though. When I saw it at night, the process was almost finished and it did not move during the 20 to 30 minutes of my taking pictures with flash.
After moulting, an arthropod is described as teneral, a callow; it is "fresh", pale and soft-bodied. Within one or two hours, the cuticle hardens and darkens following a tanning process similar to that of the tanning of leather. It is during this short phase that the animal expands, since growth is otherwise constrained by the rigidity of the exoskeleton. Growth of the limbs and other parts normally covered by hard exoskeleton is achieved by transfer of body fluids from soft parts before the new skin hardens. Some arthropods however, especially large insects with tracheal respiration, expand their new exoskeleton by swallowing or otherwise taking in air. The maturation of the structure and colouration of the new exoskeleton might take days or weeks in a long-lived insect; this can raise problems in trying to identify the species when a specimen has just recently undergone ecdysis.
Ecdysis may also enable damaged tissue and missing limbs to be regenerated or substantially re-formed, although this may only be complete over a series of moults, the stump being a little larger with each moult until it is of normal, or near normal size again.
I just could not get any pictures of the earlier stages though. When I saw it at night, the process was almost finished and it did not move during the 20 to 30 minutes of my taking pictures with flash.
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