Can I Keep Fish With A Blue Lobster?

I just got my son a Blue Lobster/Crayfish and I already had some CPD's for his tank with his Dwarf Crayfish.
The Dwarf was in his own tank though since I didn't trust him with the fish.
I was planning on taking back the CPD's so it's just the Blue Crayfish in the 10 gal, but I wanted to double check and see if it really would most likely end up with the Crayfish eating the CPD's?

I keep reading conflicting info. Some people say fast moving fish are fine, but others say all fish will be eaten eventually.

Also what's the best temp for them. I had read "room temperature" so the tank doesn't have the heater on right now, but in the winter it gets cold where we live and it could easily drop to the 60's even with the furnace going. Is that ok, or will they need a heater?

 

The CPDs will probably end up as food as they are small and in a small tank. I would get a 20 Gallon for the Crayfish as they get around 5-6" long and are very active, and it will make the CPDs happier to not be preyed on. The Crayfish should be fine in 65-75'F but prefers 70'F, I would get a heater just for the winter.

 

Lobsters eat fish - simple!

 

Thanks for the reassurance. I'll take them back. I know my son wants his fish but it would make him very sad if they got eaten and he loves his Crayfish so he'll pick him/her over the fish.

 

One thing to note is I have found a lot more info about Mexican Dwarf Crayfish than the Electric Blue one's. Kinda surprising.