Synchronised moulting?

[kiwiraka]

Both of my koura moulted today, they usually moult about a week apart. Are there any environmental factors that effect moulting? Anyone else experienced this before?

[livingart]

basically gets down to how much weight they put on and the need for a bigger exoskeleton

[willyp123]

I've heard about this before: http://www.reddit.com/r/Crayfish/commen ... ized_molt/

"Evidence of synchronous life history events exists. For example, Butler IV et al (1985) found evidence of synchrony between Orconectes rusticus and Orconectes sanborni for mating, molting, and egg hatching. This synchrony may only reach as far as individual populations. So all of the crayfish in one lake may molt at the same time, but the crayfish from another like, while they will also molt at the same time as one another, may molt earlier or later than the population in the first lake.

So that kind of answers your question, but I think you'll agree that Cambarus diogenes is different from the two Orconectis crayfish as it is a burrower.

This begs the question as to why some crayfish synchronize their molts. It may be that the molts are triggered by an environmental cue that all crayfish sense (such as temperature) or it may be a process that has evolved to help limit the amount of cannibalism that would occur if crayfish molted sporadically and soft crayfish were always available as snacks. If all, or most, crayfish molt, the whole population will be incapacitated and will not have any interest in eating one another.

I'll do more reading to answer that question, but I wouldn't be surprised if it's a combination of the two. Burrowing crayfish are sometimes gregarious at different points in their life history so perhaps this is a manifestation of that.

My question, however, is whether you have changed anything in the aquarium recently? You'll find that an increase in temperature or a large water change will often trigger a molt simply because it tells the crayfish that the seasons are changing and that it's time to go in or out of reproductive form.

TL;DR Evidence suggests that this was not a coincidence."

- From the above link

[kiwiraka]

:gpo2:

I do weekly water changes of about 80-90 litres, the only thing I've done differently recently is feeding my natives live food as the bulk of their diet but I still feed heart and shrimp which I suspect is the only food that reaches the bottom.

Thanks