Emerald crab how many are enough?


I thinking get about 15 of them in 75 gallons tanks? + some other hermit, snail
is that ok?


New Member
I had 2. They ate corals like flower pot, plate, leather. So I had to take them out (don't think it's easy, just by luck). Don't get crabs unless you want to see your corals at their meals. <img src="graemlins//urrr.gif" border="0" alt="[urrr]" />


Active Member
Well crabs are omnivors, so there is always a chance they will take a liking to your corals. However, the emeralds are great bubble algae eaters. I would add one, see how it goes and then decide if you want another one if the algae is persistant. They will go after corals if they run out of food ( algae ) so add them very very slowly and keep a good eye on them.


New Member
I have 5 in my tank and they do just fine. they have not hurt any of my coral. I hope they do not eat any thing. I have a filefish and it likes shrimp!!! So it is nice to have something small to see moveing on the bottom. ;)
Also, my tank is a 75 gal.


I have had 1 in my tank for about a month. There are two huge bubble algaes (about nickle-sized) in my tank, and he has paid zero attention to them thus far. Maybe saving up for Thanksgiving or something. :mad:


Active Member
I have one tiny one in my 46 gallon...I haven't seen him since i put him in...he hasn't touched anything yet...including the bubble algae.
1 emerald crab for every 25g
if u have a 55g then 2 emeralds
65g maybe 3 emeralds
45g about 2 emeralds
90g 3 - 4 emeralds


Active Member
I have three in my 72. I got them when they where tiny. But now they are large and they need supplemental feedings of Algae..... I use a few Algea tablets a week for them. When I drop one into the tank they race to see who can get to it first......


Active Member
15? I would say two is maybe enough and wouldn't keep any but females myself. If you go in to buy them, look at the girdle on their under-belly. The females have a dark oval with faint stripes and the males have long thin lines on their stomachs. The females are less aggressive.


Active Member
i agree with candycane. don't get a crapload of them. the idea that they eat bubble algae is hit or miss. the males get large and kill other crabs at times. some may nip at corals, but i've never seen an emerald pull at anything other than xenia, which s a blessing in disguise.
there is no set number. buy as many as you like, but buy them in increments, not all at once, so you can decide for yourself if you want more.