Slightly worried.

[g0regasmic]

I put in a new piece of live rock today. After spending a few minutes cleaning it off.

As I submerged it in my tank... It began to rain what I believe are Stone crab and tiny shrimps.

I read everywhere how horrible stone crabs are. I managed to fish out 2, one of which was MASSIVE atleast 1.5" big.

Truth is I am kinda worried.

Should I invest in a puffer fish to help eliminate my new scattered stone crab infestation? And if so, do I have to worry for the safety of my other fish?

Currently I have a Emerald Crab, 6 Green Chromis and 3 Yellow tailed Damsels, and some turbo snails nothing too flashy or fancy, but I still wouldn't want them hurt. (Although the snails I'm sure will be picked off.)

Any Advise will be welcome.

 

[mr_X]

Stone crabs? Do you have a picture of these crabs? No, you don't need a puffer and no, you don't have to worry about your fish getting killed. I'm betting these crabs are no more dangerous than your emerald crab is (which is not reef safe).

 

[g0regasmic]

Hey Doug,

I've was just trying to get a good picture but they are rather concealed right now. I know the big guy I took out was for certain a Stone Crab. He has black tip claws, but! Upon closer inspection at the majority of these crabs I realized none have black tips but the one I fished out, the rest looked alot like Lined Shore Crabs, but living in Florida and the live rock being Florida rock, I doubt they are Lined Shore Crabs. A friend told me its a high possibility they are simply mud crabs and after googling the images of baby mud crabs I am beginning to think he is right. I also noticed the minute my 10000k bulb turned on for the day these crabs are lawn mowering the live rock and eating TONS of algae so that is kinda ruling the stone crab idea out and giving the mud crab idea more points. I will try and take a good picture when they are a bit more out in the open.

Thanks for the quick response, I did not want to get a puffer after I heard of their destructive nature.

I wish to one day start a reef tank, but I will wait til I get a good handle on FOWLR and situations like this don't frighten me as much.

I'll keep you posted.

 

[mr_X]

this is what you have in your tank?

Where did you get this rock from? Did you harvest it yourself or from the LFS?

 

[g0regasmic]

The one I took out looked just about identical to this:

But the ones that are in there eating Algae right now kinda look like this:

It was given to me from someone whom uses the actual ocean to cure his live rock has some kinda bucket which holds his rock that works with the tides, so I knew I would get hitchhikers, just didn't expect THIS many.
(Don't know the exact process never cured or harvested LR before.)



(Most of my aquarium is purely ocean since I use to catch fish myself, just recently I introduced the LFS bought fish to see how they adapted with actual marine waters. All has been fine til this scare, mainly just cause I'm not a crab fan and I hear horror stories of crabs with reefs and other aquarium mates.)

 

[mr_X]

There are many crabs that look somewhat similar. here are a few species-
Crab Hitch Hikers

 

[g0regasmic]

Still no luck on a picture. But it like looks like the very first image on the page you sent me.

Either way what ever these are, this chunk of live rock is infested with them. I just noticed a few minutes ago, all the snails were on this said piece of live rock, all seemed alive, then I noticed one was turned over. I tried fishing it up and it was glued down, but not like normal, I felt a pull back. Sure enough, a crab had killed and was eating it. All 5 snails have now been brutally eaten, I took out all the shells and think I may be tossing this live rock out.

:/

 

[Sniperhank]

Toss the LR into a bucket of distilled water for awhile and all those nasty things will come running out.

 

[g0regasmic]

UPDATE:

@Sniperhank A friend of mine suggested the idea you mentioned about an hour or so before you did. I did that... and well... Lets just say I got about 3 crabs out. I knew from watching the rock carefully that WAY more then three were in, by this point I got tired of it, hooked up a hose and with my thumb, pressurized and BLASTED the rock. More started scattering, I mean to a point I had crabs COVERING my patio. But still the BIG ones I had seen, while rock was in aquarium, had not shaken free.

This rock was a disaster, so I smashed it up. It was then the crabs RAINED out. I lost actual count after 32 crabs. A roommate of mine was excited and all giddy about the crabs and literally ran behind me with a cup collecting some of them, these were some she managed to catch:

One had a very long fu manchu, and was different then all the others:

(The one on the right.) After googling I figured it was a Porcelain crab, and a few minutes after this picture, the big guy next to him ripped off both his claws.

All the other crabs were like the one pictured to the left.
Like this:

At the end of the day, the rock wasn't worth all the hassle. I tossed it out. I took that one since the guy told me it was his oldest of rocks and biggest. It costed me 5 bucks... (in the snails killed) But other then that, no major harm done.

Thanks for helping me out through my...scare, wish it would have worked out, cause the rock was nice looking.

To bad it was clearly a crab breeding ground!

 

[mr_X]

wow. 32 crabs! Amazing. Sad that you don't have a sump or something you could put them in instead of killing them.

 

[g0regasmic]

No worries only a few passed away. I actually took the rock to the inter coastal on my way to the beach, left it on the muddy shore. So the only ones which passed we the ones that ran into my grass, the rest are back at the ocean... Just different water front property.