Need some help with ID on hitch hikers

[tim7028]

My reef tank has been set up for 5 months now and all is going well. Atleast I think so? Lastnight I spotted two new occupants??? 1st a bunch (alot) of tiny bug like looking things scurring about on the live rock. They are about 1/8 inch long and are almost clear to cream colored and they move about quickly. They have legs and antenni. They don't swim, juct scurry about. What are they? Do I have a problem? 2nd I found a new crab, about 1 inch in size, 4 legs on each side, 2 larger claws out in front, dark gray in color and hides in the rock. How did he get here? I thought I've been really picky about what goes into the tank. It seems peaceful, shy. I don't want to catch and destroy but will if I have to. HELP Thanks

 

[bigarn]

The tiny bug looking things sound like Pods .... harmless and beneficial to have.
We would need a picture to help ID the crab ..... does it have pointy claws or rounded ones?

 

[tim7028]

pointy

 

[schneidts]

Well, the first critters you described sound like Amphipods. They are an essential part of your reef environment. Usually you can find them on the rocks with a flashlight at night. Do a search on this forum for Amphipod or "pods", you should find lots of helpful info. As far as the crab, there are so many crab hitchhikers out there...who knows what it might be. I want to say larger claws are an indicator of bad crabs, but I'm not to sure on that. They hide in rocks and come in on new coral additions.

 

[tim7028]

I have an emerald crab and sally lightfoot also. The claws are about the size of the sally lightfoot, not near as big as the emerald matrix crab. Doe's this help. The only way I can see him is within the cracks of rock. He's shy!