Some sort of crab on my rock

[dsnider]

Hello, just joined the list. I've only had my tank a couple of weeks, but just found this little guy on my rocks. He wasn't on my invoice, so I didn't purchase him. Any thoughts on what he may be? I'm a little concerned because I found a shredded Hermit Crab today and my Red Bali star looks like someone took a bite out of her as well. I've also lost a yellow watchman. The current (known) inhabitants are 2 clown fish, 1 firefish, 1 pistol shrimp, 2 cleaner shrimp, 1 banded brittle star, and one neon blue gobie.

 

[usmcmarc]

Cant really tell what kind of crab it is...but, if you have missing fish and beaten up creatures...then that crab would be my prime suspect. Banish it to the sump or take it back to the LFS...Before you lose more livestock.

BTW...What are your water parameters?

And Welcome to AA!!!!!

 

[pat8you]

No idea what kind of crab it is but almost all crabs are opportunistic eaters and will eat fish inverts and clean up crew if it can get its claws on it. So I'm with usmcmarc, get rid of it. To the sump he goes (or if your heartless like me, the backyard) for not playing nice with others.

 

[melosu58]

To me it looks like a Sallylightfoot crab. I`ve had a couple in my tank with no problems. They are great scavangers. As the others said though a crab is a crab and caution should be taken just in case.

 

[dsnider]

The pictures of Sally Lightfoots that I have seen have much different claws. I called my local fish store and talked to them, they said that a typical way to tell if a crab is "reef safe" is to look at the claws. If they are sharp and pointy, it's most likely a predator type crab and isn't safe. If the claws are more rounded and less sharp, it should be safe. In my picture, you can see the claws look like friggin' daggers. I pulled him from the tank, so we'll see how my fish do.

 

[Ziggy953]

Neat little guy though...How did you catch him?

 

[dsnider]

At first it was a total pain in the rear, chased him about a bit, but he always went and hid in the rock. I didn't want to rip everything out and freak out the tank, so we let things be for a bit. In the end, it wasn't that bad. After a couple of hours, he climbed up a piece of live rock (I think it used to be antler coral), I had a net that I slipped in extremely slowly and moved below him, then my wife put her hands on the other side of the rock and as she went to grab him, he slipped down, right into the net. I think we got lucky.

 

[Ziggy953]

I think you did too! Crabs can be tough to catch especially in a tank that has lots of rock and hiding places.

 

[melosu58]

I`ve always heard that the ones with the big fat claws are the ones you need to watch out for. A better pic will help alot but for now I still say a Sallylightfoot crab.

 

[dsnider]

Answering a question from usmcmarc, my water parameters are such:

Temp: 77
SG: 1.023
PH: 8.5
ALK: 3.57 meq/L (10 dKH)
Ammonia: 0
Nitrite: 0.1
Nitrate: 20*
Calcium: 440
Phosphate: 0

*I have a question on the Nitrate. Is it possible to get a bad test kit? I have tested the water 3 times with the Nitrate kit. It always comes back between 10 and 20. I took the water to the LFS to have it tested and they tested the nitrate @ 5. The time difference between the two tests (mine and theirs) was one day. All of their other tests were similar to my own. The reason I suspect the kit to be faulty is that when I opened the box, it looked like some of the solution (yellow) had leaked from the bottle.

 

[cmor1701d]

Test kits do expire. Is there a date on the box? You might want to get a different kit just to be sure. Does the lfs use the same brand as you?

 

[usmcmarc]

Answering a question from usmcmarc, my water parameters are such:

Temp: 77
SG: 1.023
PH: 8.5
ALK: 3.57 meq/L (10 dKH)
Ammonia: 0
Nitrite: 0.1
Nitrate: 20*
Calcium: 440
Phosphate: 0

*I have a question on the Nitrate. Is it possible to get a bad test kit? I have tested the water 3 times with the Nitrate kit. It always comes back between 10 and 20. I took the water to the LFS to have it tested and they tested the nitrate @ 5. The time difference between the two tests (mine and theirs) was one day. All of their other tests were similar to my own. The reason I suspect the kit to be faulty is that when I opened the box, it looked like some of the solution (yellow) had leaked from the bottle.

IMO only,
I would get that temp up to 79

I would get that SG up to 1.025 (If you DON'T have an ATO, then leave it at 1.023) NSW is 1.026, but if you dont have an ATO and forget to keep an eye on evaporation, your SG will skyrocket.

pH is a little high..I would keep an eye on it..did you take that reading in the morning or night?

Alk is ok

Nitrite should be 0..something might be amiss if you have any trace of nitrite.

You need to get those nitrates as low as possible. They will effect your anemone, corals and could be the precursor to algae issues later on.

Calcium is fine. If you get any SPS corals you will need to get it above 450.

As for the test kit..sure get another one. Won't hurt.