arrow crabs - reef safe or not?

[Liz]

Hi all,

Before I ask advice about arrow crabs I just want to mention that I have recently discovered the immense benefits of purchasing an RO/DI unit for my marine tank. Wow ... the entire tank and I mean entire tank is brimming with life and not with irritating algae .... It has restored the bounce in my enthusiasm for creating my dream tank.

Ok now I have that off my chest I'll get back to the point.

My bicolour blenny decided to explore pastures new and took a dive over my wier. It took me 3 days to discover his whereabouts and half a day to retreive him and to prevent a recurrance. In the process my fingers encountered bristleworms. So I am wagging a war - I am prepared to tolerate a few but they are getting out of hand. I fished out an enormous one last week (the size of a pen!).

My research suggests coral banded shrimps or arrow crabs but reports on their suitability vary from "great additions" (provided purchased singularay or in mated pairs and not both species in the same tank) to destructive and should not be kept in reef tanks.

Does anyone have any experiences (good or bad) please on these two critters. Or indeed any thing else that controls bristleworms. (My boyfriend who is a great fan of zombie and horror films would like to add something with as many claws as possible)

Thanks in advance
Liz

100 + gallon tank with sum, protein skimmer, wave machine, live rock
inverts: 2 serpents, 2 fire shrimp, 2 cleaner shrimp, 10 blue legged hermits, 5 red legged hermits, 4 bumble bee snails, (several other species of less exciting snail)
fish: bicolour blenny, purple tang, yellow tank, 2 yellow tailed damsels, 2 clowns
corals: button polyps, 2 large leather corals (soon to add euphillia & xenia)

 

[tmcpeek]

I have one and it is fine. Just keep 1 as multiples will fight til death

 

[Liz]

Thanks. Do you have shrimps and corals in your tank? Only I read something somewhere that they are destructive to corals and may attack shrimps (this could be just the Coral banded Shrimp but if it's prepared to take on this beast will it not attack my cleaners??????)

Sorry - it's not that i don't beleive you just that I'd never forgive myself if i got up one morning to find my cleaners snaffled and a very pleased and fat looking arrow crab!

 

[theatrus]

I've seen a lot of anti-crab opinions around. Some make sense (stone crabs, etc), but some make crabs out to be the devil in general, and therefore you should have a tank with water and some snails (forget fish, they eat corals too! you can't tell apart a clown and an angel!)

But I've heard arrows are reef safe.

 

[tmcpeek]

I have peppermint shrimp, pedersons cleaner shrimp and a coral banded shrimp. I have watched a peppermint walk right over the legs of the arrow and the arrow ignored it. It seems very docile and is always out in the open.

I have many mushrooms, a couple of toadstools and cabbages and the arrow does nothing to them either. HTH

 

[Liz]

Thanks everyone.
I have of course made the rather huge assumption that both arrow crabs and coral banded shrimp eat bristle worms. (My research suggests so but then it was also very anti-crab too)!

Does anyone have any advice on whether I should get an arrow crab or a coral banded shrimp. I'm undecided between the two provided both eat bristle worms and co-habit with my other tank mates.

Thanks again everyone
Liz

 

[quarryshark]

I think with any animal that has mixed reviews you are rolling the dice a bit. Every animal is different and some times you just have to try and see what happens.
With a 100 gallon tank you have a lot of real estate in there. Plenty of room for these animals to roam. I would be inclined to give it a try. JMO
Personally I think the CBS is more attractive, so that would be my choice.

 

[SeriousDude5]

I have an arrow crab in my 65gal. and it seems to be doing fine except my blue demsil annoying it sometimes.

 

[austinsdad]

I had an arrow months ago, but got rid of it. 'Bout 4 inches across, total leg span. One day I came home, he was munching on an electric blue hermit. I thought the crab may have died and he was eating the remains since the tank was only 3 months old.

The very next day, he was munching on a cleaner shrimp. I'll never know if stuff was dying and it was one heck of coinidence, but I didn't take any chances and returned him. I did see him reaching for shrimp every once in a while and it made me suspicious.

I've had a Coral Banded shrimp for a moth or so now. He's fun to watch. Haven't seen him munching on anything, but he does kinda feign at it. I'm thinking he just likes his space and does that to defend rather than attack. I kinda wish I had a mated pair now.

Then there's the school of thought that says each critter has it's own unique personality. You may or may not have a problem, it's hard to say IMO.

 

[Liz]

Sorry to hear about your evil arrow crab.
The more I hear from people the more I am swaying towards the CBS (it would be my choice for looks - arrows kinda look like they're from the depths and are some what scary looking IMO).
I'm certain about each critter having their own personality though. My bicolour blenny "barnacle bill" has just let his show! I put a very nice xenia frag in my tank yesterday and placed it in an ideal spot above his barnacle castle. Bill has been grumpy ever since and point blankly refused to come out of the lowest part of his castle even for food. That is until I see him this lunch time making his point by taking chunks out of the xenia and spiting it out right in front of me.
So I've moved the frag elsewhere and he's happy now, has cleaned his castle and has left the frag alone. Little s*d. Bags of character though

I hate taking gambles but I really have to do something about my bristle worms!
Fingers crossed I can find a friendly CBS!

 

[tmcpeek]

Have you tried a trap?

Also I spoke too soon. I have had my crab in my tank for 3 + months and last night I added two cleaner shrimp to the tank. Well guess what the arrow had in it's mouth this morning? Cleaner Shrimp tail..Now the task of trying to catch a arrow crab in a 225 gallon full of live rock and caves and crevices

 

[Liz]

Yep! Bristle worms seem too smart for traps even with the bait being fresh clams that they normally come out for in the tank. Kept my fire shrimps entertained trying to undo the trap though.

I've been using tweezers to grab the odd one or two out of the tank when ever I get the chance as this has seemed to be the most reliable method so far.

Good luck catching the arrow crab.

 

[Liz]

I'm abandoning the idea of an Arrow crab (for the moment at least)

Has any one had any luck with the Coral Banded Shrimp. Firstly do they eat bristle worms and secondly but equally importantly do they harm cleaner shrimps? I've seen CBS sold in the same tank as fire shrimps in my local store but never in the same tank as the yellow/red cleaner shrimp. (But then my LFS don't house the fires and cleaners together either and they co-exist in my 100 gallon happily.)

Any help would be greatfully received
Apologies for the long topic. I'd rather get my facts straight than make a purchase I later regret.

 

[lando]

I have a CBS in my tank along with a blood shrimp, 2 cleaners and 2 peppermints. All is well. My CBS does not bother anything. In fact, he cleans my copperband butterfly. Ihave never seem mine eat bristle worms.