I do not think they could be kept as pets for a number of reasons. I think it would be better appreciated in the wild. To be fair, I dont think a lot of animals kept as pets are appropriate for keeping.
I was not aware they are endangered.>>2363383
I could not say, There are likely meaningful differences that escape the layman's untrained eye, like me, but no one here has ever expounded on them beyond taxonomy. I appreciate them both generally, so I haven't been moved to learn the distinctions.
For me, it has to be more than anatomical to be relevant. I know, for example, that symmetry has something to do with it. But why are there differences and how does it impact the creature. The distinction between a panther and a jaguar, for example, aren't meaningful unless its explained how those differences emerged and how they shape the life of the creature. How does it affect how they eat, their migration, their life cycle.
If you say that one simply has bigger claws than the other, then the distinction is no more relevant than between one cousin being taller than the other. Taxonomy is more than pedantic cataloging. We are supposed to understand what those differences mean. A seal and sea lion appear quite similar. But the differences, mild as they may appear, have bearing not only on the creature in evolution, but on how they live.
Thats what I'd like to distill; how are the two separate by their differences in applied evolution? Where they shaped differently by environment, by food sources? Or was there more? Like bees and wasps. They have distinctions that seem minor until you realize there is so much evolutionary differences spanning so much time between them.
Anyways, I like crabs. Even things that arent perfectly 'true' crabby, probably owing to my fascination with crustaceans and inverts generally.