Halloween Crab: Reef Safe?

[KeMiKiLL]

Before picking up this Halloween crab, I was seeing it deemed "reef safe" everywhere. I'm not so sure that is accurate.

This guy has been harassing one of my wall hammers for about a week now. I thought the hammer was pulling back due to the unwanted attention, now I'm not sure exactly what is happening. Is the crab eating the hammer?

Today I got home and, sure enough, the crab is sitting on top of the hammer picking at it again.

Here is what the hammer looks like now:

This is a really beautiful neon green purple tip hammer and up until yesterday the bright green and dark purple were as least partially visible in the centre. Now I see nothing and I'm not sure if that is what it looks like normally when really tucked in, or if this crab has been eating the hammers.

Are those Halloween crabs really reef safe?

 

[ubasu]

You are referring to a Halloween hermit crab right? I would throw him in the sump and see if things change. I never had any issue with my halloween hermit crab but some people are jerks just like some crabs can be.

 

[PR_nano]

I now truly believe the saying that crabs are opportunistic. Bought a Pipe Organ frag and caught my scarlet hermit crab munching on it. Must have tasted great since I moved it to a frag rack and he kept trying to get to it, lol. I like crabs but might start going snails only in the future.

 

[Uncle99]

It is not possible for mostly any crab to be reef safe, never safe, just varying degrees of risk.
Once I removed every single crab from my DT, I have had NO, mysterious deaths in years.
In the end, they seemed to have no value and quickly learned that food “falls from the sky” everyday, so why work for supper.
Snails I have quite a few.

 

[KeMiKiLL]

I now truly believe the saying that crabs are opportunistic. Bought a Pipe Organ frag and caught my scarlet hermit crab munching on it. Must have tasted great since I moved it to a frag rack and he kept trying to get to it, lol. I like crabs but might start going snails only in the future.

Yup. No matter how many times I would move this guy, he would be back on that hammer the next time I'd check - just picking away. I never saw him actually tear a chunk off but he was putting something in his mouth...

 

[KeMiKiLL]

It is not possible for mostly any crab to be reef safe, never safe, just varying degrees of risk.
Once I removed every single crab from my DT, I have had NO, mysterious deaths in years.
In the end, they seemed to have no value and quickly learned that food “falls from the sky” everyday, so why work for supper.
Snails I have quite a few.

I'm thinking I might go all snails too. This is in my 32 gallon Biocube and the small blue leg and scarlet hermits don't seem to cause trouble. I hardly see them actually but just when I think they disappeared, I'll see them again.
In my 5 gallon pico, there are two larger crabs - one blue leg and one scarlet - and they've never touched anything although I do see polyps close up option when they clumsily bump into them.

 

[nanonøkk]

i never trust any crab in a reef tank as any crab can turn and eat corals and other things as they are opportunistic that’s why i went with snails only in my new tank and i haven’t had any problems i highly recommend snails over crabs

 

[KeMiKiLL]

You are referring to a Halloween hermit crab right? I would throw him in the sump and see if things change. I never had any issue with my halloween hermit crab but some people are jerks just like some crabs can be.

Unfortunately, no sump on this 32 gallon Biocube. Would he survive in the refugium chamber? It has a shelf that will keep him separate from the Chaeto. There is one chamber that only has the heater heater another that has the return pump. Right now he is in a small jug I filled with water from the tank and hung on the side. I put up a "Free to a good home" ad but I don't want him to have problems in the meantime. It's not his fault he is a gluttonous hammer eating jerk - allegedly.
That's another thing. Could a 1.5" hermit crab eat a whole 4 inch wall hammer in 5 days? Seems like alot.

 

[ubasu]

Unfortunately, no sump on this 32 gallon Biocube. Would he survive in the refugium chamber? It has a shelf that will keep him separate from the Chaeto. There is one chamber that only has the heater heater another that has the return pump. Right now he is in a small jug I filled with water from the tank and hung on the side. I put up a "Free to a good home" ad but I don't want him to have problems in the meantime. It's not his fault he is a gluttonous hammer eating jerk - allegedly.
That's another thing. Could a 1.5" hermit crab eat a whole 4 inch wall hammer in 5 days? Seems like alot.

What about just dropping him off at a LFS?

 

[Rickybobby]

I have a Halloween hermit. He’s a model citizen actually all of mine have been I like to collect. I have dwarf blue. Halloween. Polka dot scarlet and African and pacific red leg

 

[ScottR]

Like said here, crabs are opportunistic. However, they will do their job as a clean up crew and sense something that is dying as well. Not saying here that the hammer was dying, but if it was, the hermit would have sensed it and did his job.

 

[DirkCourage]

Oof. My HH has gone after a few things. He was really beating on a pocillopora that I think got a little light burned, so I think you may have witnessed some scavenger behavior. Though he also took a small chomp on a monti that recovered. Could be he’s agitated/aggressive because he’s molting and looking for a new shell. If you’re lucky your LFS might have an extra cone shell and he may calm down. That’s a tough loss though.

 

[KeMiKiLL]

What about just dropping him off at a LFS?

I was thinking about this today, actually. I have to buy an ATO for my other tank anyway, so good reason to make the drive out.

 

[diverrad]

I gave up crabs a long time ago. You simply can’t trust them. They tend to do the really dirty deeds at night. On several occasions I have seen both blue leg and zebra crabs pulling snails out because they fancied their shell. Banish him to the sump or fuge..

 

[KeMiKiLL]

I gave up crabs a long time ago. You simply can’t trust them. They tend to do the really dirty deeds at night. On several occasions I have seen both blue leg and zebra crabs pulling snails out because they fancied their shell. Banish him to the sump or fuge..

Do you think he would do okay in my small refugium until I can make it out to the LFS in a couple of days? This is a 32 gallon Biocube with the Intank Fuge basket, so it's about 5" x 3.5". All you can eat chaeto in there though.

 

[diverrad]

I think he would be fine in there for longer than a few days if need be.

 

[Uncle99]

I'm thinking I might go all snails too. This is in my 32 gallon Biocube and the small blue leg and scarlet hermits don't seem to cause trouble. I hardly see them actually but just when I think they disappeared, I'll see them again.
In my 5 gallon pico, there are two larger crabs - one blue leg and one scarlet - and they've never touched anything although I do see polyps close up option when they clumsily bump into them.

If you like them cause you like them, sure, just make sure their are empty shells for them to grow into.
Blues are fine, ifI needed some cleaning I would use them.
I have diverse snail populations, they polish, and don’t hunt any of my friends.

 

[Zoa_Fanatic]

Do you think he would do okay in my small refugium until I can make it out to the LFS in a couple of days? This is a 32 gallon Biocube with the Intank Fuge basket, so it's about 5" x 3.5". All you can eat chaeto in there though.

I know this is an old thread but I recently bought a used biocube 16 with NO cheato or anything in the sump. The guy I got it from had dumped a zebra hermit in there on accident about a year ago and never bothered to fish him out. The little dude was still alive despite the tank sitting nearly empty with no heat or light for a month after a year of being in chamber 2 of the biocube. I plucked him out and threw him in my 32. Crabs are resilient. and you'd be surprised how much food gets into those chambers. I also throw a blue leg back there every now and then to eat the bristle worms that seem to grow like mad in my sump

 

[Nanolifeuk]

Yeah old post but I’m in the same boat. Looking back he was probably the culprit for a lot of losses. Even if it’s not picking at the coral just surrounding algae i guess the shell can stress the coral out & recede if constantly harassed.

I run a fluval spec 60L , Which is a pain in the butt because it was stock for freshwater. It has a extra hole in the sump @ the bottom and I swear more detritus goes through that than the overflow/filter floss. it might serve a purpose cleaning up in there for me.

futhermore, my intank media basket has a little gap underneath where I can check on him. Think I will do as zoa fanatic says and banish him ! (It will be funny to watch it tugging on the bars, like a prisoner).