Crab to ID

[kevincsweden]

Need Help Identifying Crab

I've know that a few crabs hitched into my tank with some live rock, but I ignored them at the time because they were so small and I had no fish for them to bother. Now I have had a few fish living in the tank for about two months and recently realized how large and intimidating the crabs have grown. I managed to catch one of them today, and as far as I know they all look pretty similar to this one with the exception of slightly varying color.
Can anyone help me determine if this guy is a threat to my tank? If so what should I do with it?

[ToddTT]

Sally Lightfoot?

sally lightfoot - Bing

[ToddTT]

Live Rock Hitch Hikers

Crab Hitch Hikers

[leebca]

I have moved this post/thread from the fish forum to the Reef Forum where they are more familiar with invertebrates.

[Steve McKay]

It is a Sally Lightfoot and I would recommend removing it.

[ToddTT]

From LiveAquaria's description:

The Sally Lightfoot Crab is also known as the Nimble Spray, Short, or Urchin Crab. It has a brown body, with orange to yellow rings on the legs. It actually belongs to a family of shore crabs, however, it is less likely than the other genera to go on land. Its carapace is very flat. which allows it to hide in small crevices within rock work.

It prefers a strong current and will require a large aquarium with large amounts of rock work where it can hide and scavenge for detritus. It will also eat algae. When large, it can become aggressive and catch and eat small invertebrates and fish.

[Steve McKay]

From LiveAquaria's description:

This is why I recommend removing it. I had one eat my Skunk Clown about 20 years ago.