TGW1, the skeletal remains you see might be from them moulting and growing larger. Their exoskeleton doesn't stretch, so to get bigger they shed it. A young crawfish could moult almost once a month for their first year of life, then 3-5 times their 2nd and usually last year of life.
esshup, There you go again. helping us (me) who never thought of them molting, and leaving their skeletal remains along the shore line. Yep, I have seen that, along with sometimes seeing just a big claw where I thought the birds or coons had a good meal. esshup thanks for expanding my small thinking.

Tracy