Crabs in a 20 gallon tank

[elkman]

I plan to have 2 blue legged hermit crabs, two pom-pom hermit crabs, one porcelain hermit crab. Would I be able to add a emerald or spider decorator?

 

[Fish Fan]

I have and would, but emeralds can be a bit of a problem sometimes.

These threads may help:
https://www.reef2reef.com/threads/crabs-in-a-20-gallon-tank.1098571/#post-13332835https://www.reef2reef.com/threads/plan-for-20-gallon-tank.1098575/

 

[elkman]

I have and would, but emeralds can be a bit of a problem sometimes.

These threads may help:
https://www.reef2reef.com/threads/crabs-in-a-20-gallon-tank.1098571/#post-13332835https://www.reef2reef.com/threads/plan-for-20-gallon-tank.1098575/

So you think I could fit pom-poms a emerald and a porcelain in a 20 gallon tank?

 

[Fish Fan]

So you think I could fit pom-poms a emerald and a porcelain in a 20 gallon tank?

I do. The pom poms and porcelain crabs are reasonably peaceful. I had about 6 porcelain crabs in a 15 gallon with a decorator and an emerald, plus a cleaner shrimp and many snails. Emeralds can be hit or miss, but I would try one and remove it if it becomes a problem.

I'm happy to help you here, but your question seems to have been asked and answered more than once recently. Is there some specific question or concern you have?

You can only play the averages with livestock aggression and interaction. Anything can happen, nothing is 100%, but I've typically had good luck with the emeralds I've had.

 

[elkman]

Yeah, sorry I’m just trying to be 100%

I do. The pom poms and porcelain crabs are reasonably peaceful. I had about 6 porcelain crabs in a 15 gallon with a decorator and an emerald, plus a cleaner shrimp and many snails. Emeralds can be hit or miss, but I would try one and remove it if it becomes a problem.

I'm happy to help you here, but your question seems to have been asked and answered more than once recently. Is there some specific question or concern you have?

You can only play the averages with livestock aggression and interaction. Anything can happen, nothing is 100%, but I've typically had good luck with the emeralds I've had.

Yeah, sorry I’m just trying to be 100% with everything I do since there are some people on Reddit who are even saying that emeralds will always kill the pom-poms.

 

[Fish Fan]

Yeah, sorry I’m just trying to be 100%

Yeah, sorry I’m just trying to be 100% with everything I do since there are some people on Reddit who are even saying that emeralds will always kill the pom-poms.

No worries. That's possible, I don't think it's a 100% certainty. But out of all the critters you've been talking about the emeralds have the greatest potential for turning on tank mates and nipping corals.

 

[Fish Fan]

Also, get off Reddit! Embrace R2R :)

 

[Crabs+Shrimps-69]

A sponge decorator would probably be better than a spider decorator because of their size.

 

[StartingATank]

I have and would, but emeralds can be a bit of a problem sometimes.

Hi, sorry to bug you, but I have an emerald crab in my aquarium and I want to know why they might be problematic, so I can look out for these things. My crab has found a little cave in the back of my rock structure and only comes out at night, and I think that maybe he might have attacked on of my fish when they were first introduced, but it was only a little scratch. Is this the problems you were talking about or is it something else?

 

[Crabs+Shrimps-69]

Hi, sorry to bug you, but I have an emerald crab in my aquarium and I want to know why they might be problematic, so I can look out for these things. My crab has found a little cave in the back of my rock structure and only comes out at night, and I think that maybe he might have attacked on of my fish when they were first introduced, but it was only a little scratch. Is this the problems you were talking about or is it something else?

I've heard the reason is because when they get larger, some (particularly the males) develop a taste for coral.

 

[Fish Fan]

Hi, sorry to bug you, but I have an emerald crab in my aquarium and I want to know why they might be problematic, so I can look out for these things. My crab has found a little cave in the back of my rock structure and only comes out at night, and I think that maybe he might have attacked on of my fish when they were first introduced, but it was only a little scratch. Is this the problems you were talking about or is it something else?

I've had them before and they've been fine for me, but they can nip at some corals, and can be aggressive towards other inverts and even fish are not off the table. It's not that they are terrible, just keep your eye on them and see if they are bothering anything else in your tank.

 

[StartingATank]

I've had them before and they've been fine for me, but they can nip at some corals, and can be aggressive towards other inverts and even fish are not off the table. It's not that they are terrible, just keep your eye on them and see if they are bothering anything else in your tank.

I've heard the reason is because when they get larger, some (particularly the males) develop a taste for coral.

Ok, thanks for the info.
My other inverts seem to be doing fine with him, but I will watch my hermit crab and the emerald because they haven't met yet.
Also, how do I tell if it is a male? I have had him for about 3 months and he is very small, less than an inch wide including legs

 

[Crabs+Shrimps-69]

Ok, thanks for the info.
My other inverts seem to be doing fine with him, but I will watch my hermit crab and the emerald because they haven't met yet.
Also, how do I tell if it is a male? I have had him for about 3 months and he is very small, less than an inch wide including legs

Looking underneath the crab
I don't know what to look for though

 

[Fish Fan]

Ok, thanks for the info.
My other inverts seem to be doing fine with him, but I will watch my hermit crab and the emerald because they haven't met yet.
Also, how do I tell if it is a male? I have had him for about 3 months and he is very small, less than an inch wide including legs

This post may help:
https://www.reef2reef.com/threads/male-vs-female-emerald-crabs.503367/post-5354650

 

[StartingATank]

This post may help:
https://www.reef2reef.com/threads/male-vs-female-emerald-crabs.503367/post-5354650

So I looked at this article, and I will look at it once I can, I am just timid with him because he seems easily scared and quick to defense. Also, I saw that in the diagram, the female crabs had more round claws, while the males had longer claws and slimmer. I don't know if this will help determine without me having to pick him up, but if the picture of the claws also can determine a difference, then mine would be a male and I would keep an eye on him.

 

[Fish Fan]

I wouldn't worry too much if he's that small. And even when larger, I wouldn't go to extremes to sex the crab, there's no guarantee that a female won't nip either. Just watch him and see if he's causing any trouble. I think most like you'll be fine, or it will be obvious that the crab needs to go.

One thing to consider: If you look at your tank one day and your crab is eating the dead remains of your prized fish, that is not at all a guarantee that the crab killed the fish. Many times something will kill livestock, and the scavengers will do their job and find the fish after it died.

And if the crab is going to nip corals, that should be pretty obvious. It's a much larger concern with those keeping expensive, and slow growing corals.

 

[StartingATank]

Yeah, thanks for the insight. I don't plan on keeping any extremely expensive corals, they most expensive one I might get would cap at $100. But thanks a lot for your interest and input.