I think the confusion here has to do with "how long the molt takes". The actual molting process from the splitting of the thoracic tergites to the final pulling free of the raptorial appendages usually takes at most a few minutes. I've watched many stomatopods molt in under a minute. However, the behavior of the animals before and after the molt changes dramatically depending on the species and the size of the animal.
Usually the first sign of an approaching molt is increased digging or cavity maintenance. The animal may also become more aggressive. Next it will probably stop taking food and finally become more secretive. Many species will actually seal themselves in their cavity or burrow. After the molt, various things can happen. Odontodactyloids usually remove their entire moltskin from the burrow and bury it some distance away. They do this only a few hours after the molt. Eventually they may dig it up and eat it, but I don't know if this is an artifact of being kept in a small aquarium or whether this happens in the wild. I have video of the burying, but not the consuming. The removal of the moltskin from the burrow may prevent predators from keying on the odour, or they may bury it to retain the skin and its nutritional value for later when they can process it.
There is also considerable variation in how soon animals will accept food and catch and process it themselves. A species like G. chiragra will remain sealed up for 10 days or more before opening the door and hunting for snails. O. sycllarus will often take food a day or two after molting, although they won't hunt for several days. O. scyllarus often do not keep their burrows closed after molting. This is particularly true if they are living in caves or pvc in and aquarium.
The other variable relating to how long the process takes is the size of the individual. The smaller the individual of a given species, the more rapidly it completes the entire molt process. A 4 cm juvenile O. scyllarus will go through the entire molting sequence in a couple of days. A large 15 cm adult may take two to three weeks.
So, when asked how long the molt takes, we can say that the actual shedding of the cuticle usually takes only minutes. If it takes longer, there is a problem and the animal may not survive. However, that only addresses the actual ecdysis or shedding of the skin. The entire molt process takes days and even weeks. There are major physiological and behavioral changes that must occur and that takes time.
I suspect that your animal molted and buried the molt skin. You probably didn't realize that this had happened because the next time you fed it, it accepted food.
Roy
