Think identifying this creature looks rather complicated, more than just a quick glance! Prob ok, but better safe than sorry. Also I see on your profile that you keep it with fish. A word of warning - crayfish will definitely try to eat your fish. If it catches one it will tear it apart.
What are the species of fish its in with? Very few will be safe if they are within size range of or smaller than the cray. Generally they are considered non-community, you might find your riding your luck on this one. Most people who have then usually are, and they don't realise it or believe it until one day they wake up to find the cray has made a kill in the night, and is chewing a beloved fish in front of you.
I have 2 Golden Gouramis (think thats spelt right) one is about 3" long and the other 1 1/2" long and 2 scavengers one is about 3" long and the other is 5" long. I'd love to attach a photo but it won't upload, I don't know where the problem is I usually have no problem. Thanks
Nobody ever does until they get one , and then its too late. Moral being, pre-empt problems don't ride luck. I can only explain it so many ways. Its a big cray, a total omnivore, in a tank with lots of soft bodied creatures it could kill if it takes a mind to, and by experience, many crayfish do just that.
You can't say you did'nt go forward without that knowledge passed on to you.If you get a fish eaten because you did'nt listen then thats your responsibility, I can do no more. A crayfish has primitive , primordial instincts to take advantage of feeding opportunities. Size may have prohibited it from taking fish so far, but that won't last forever. Just because you don't have a problem now doesnt mean you wont't have one in the near future, thats what i'm trying hard to tell you. I'm not saying it for laughs, i'm trying to stop you from getting an undesired fish death.
Theres nothing in your tank too big for a cherax cray or marron to take out. When the mood takes him, he'll dispatch them with ease, and usually at night. You don't keep species together where that can happen, its fundamentally neglectful care, like it or not. You can choose to ignore it, or do something about it. A good fishkeeper would do something about it before it happens. If the fish matter to you, you'll give it some thought. Denial of the problem won't make it go away. A severe risk is being run here, theres no avoiding it.