2 months ago I collected a dozen of the little crabs from a tide pool by my house. the water temp was well above what my tank at home runs at so these little buggers are definitely capable of of handling 79 degrees. Looong term not totally sure. But after 2 months I have 9 out of 12 crabs remaining, one was killed in a fight with another the first day, another had only one claw so he was kinda doomed (but survived 3 weeks) and another one died last week, he was the only be I tried putting into a nano tank which I barely feed, sorry buddy

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Some of them are more scrappy than the others. There are many different species with different coloring.
I doubt they're as good at clearing algae than a hungry emerald crab (some of them do graze) but my last emerald slept all day hanging upside down and didn't appear to do anything anyway.
Happy to report all have been reef safe, haven't bothered any corals, fought or killed any of the tropical species of snails or hermits or fish, they just go after each other during feeding time especially the a
Red one.
They get fed 1/4 of a silverside every couple weeks and extra NLS pellets that fall to the floor daily.
Do so at your own risk obviously, but I have no problems to report. Collecting them during summer from a warm tide pool made sense so there was less stress acclimating them but not sure how much of a difference there will be. Theyre probably gonna start wondering when summer will end?!