How to distinguish Lobster and Crayfish?

[Feline]

From what I read in the posts, I now learnt that lobsters are in salt water and crayfish are in fresh water. But how can I tell which is which? like are there any difference in their body? their shell?

 

[Jamnog]

i think the pincers are thiner on cray and cray ar esmaller but im not well read when it comes to lobsters (considered pun on the word red... thaught better of it)