crawfish ???

if you do you are going to need to give the crawfish a few caves or so and feed them well because they would attack your fish if the are hungry.

How large is the tank? Unless it is massive, I wouldn't add any crawdads.

at lower temps, crayfish will be substantially less agressive due to a lowered metabolism, so you may (ie: no guarantee!) be fine provided you give adequate hiding spots. when i had mine in a heated tank (around 79), he was a voracious eater...and an efficient hunter, picking off zebra danios much to my chagrin at the time. so i moved the cray to a feeder guppy breeding tank, thinking he might pick off some of them and curb the population a little. well, i don't run a heater on live-bearer only tanks that i want to breed based on personal experience (temp thus around 70). the crayfish's appetite was effectively curbed instead of the guppy population, and i never once saw him catch and/or eat a single one. he just scavenged around occasionally...so i still keep him in a unheated tank with guppies, he's perfectly healthy and has molted twice under these conditions, but he doesn't attack fish anymore.

could be a fluke, but i have read about the temp/metabolism being a huge factor in crayfish aggression. it's still a risk for sure, even if it's lower than in a heated tank.

If you're keeping crayfish remember to make sure your top is covered. It's a surprise to walk across the room your tank is in and find one crawling across your carpet. They are good at escaping.

Shubunkins are sleek enough to have a chance, but in my opinion it's only a matter of time until the crawfish gets a meal.