just so you know, in all states in the USA it is illegal to release wildcaught or captive born animals of any kind into the wild. Some become invasive, others are a no-no for reasons stated below.
This includes your crayfish if it has been in captivity over 90 days. It could easily introduce foreign pathogens, diseases, or parasites from your house/tank into the wild populations that have in some cases almost wiped out entire species. The wild animals dont have built up immunity to these things.
If you dont want it and its been longer than 90 days, you should find it a new home. DO NOT release animals back into the wild that no longer belong there.
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This is taken from Melissa Caplans site:
Releasing Captive Reptiles and Amphibians
She is referring to reptiles and amphibs in this document, but it is the same for any other species of animals.
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Releasing Long-term Captives: Why you can't do it.
It is illegal to release non-native wildlife into any area. Nonnative is any species that is not native to the area you are thinking of releasing it in. Many people do realize that there are many species of box turtles, for example. Just because there are box turtles where you live in Texas does not mean that they are the same species as the box turtle you brought back from your trip to Virginia.
It is illegal to release native wildlife without a permit. Even wildlife rehabilitators require special permits and licenses to operate.
It is morally unethical. Assuming you want it to live, giving it to a pet store for resale is probably not an option. The reason the California desert tortoises are under
threat of extinction is because those populations not disturbed by habitat destruction are being decimated by a viral infection spread into the wild populations by sick former captives who were released into the wild to either live or die - the former owners didn't particularly care which, and had some foolish notion that if they were meant to get better, they would.
In addition, long term captives may be carrying organisms against which they have developed immunity but against which wild populations have not - thus a release such as you plan could be devastating to the native turtle populations. And, conversely, the wild populations may have immunity against organisms against which your foundling does not - again, a release could be lethal.
Other animals may be affected as well, as many of the infecting organisms will happily inhabit many different types of hosts.
Releasing long term captives outside their normal range, even if it is in similar habitat, may also prove fatal as many of them fail to learn to feed, hide and generally survive. (One study of wild rattlesnakes resulted in most of the study group dying, despite the fact that the biologists released them into what they considered to be prime habitat for that species, an area which was devoid of any other rattlers.) Also, they have little natural defenses against predators which may be different than the ones in the locale in which they evolved.