Crab Hitchhiker ID Help

ACNaturalHistory

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Hey Everyone!

I got TBS live rock @LiverockRocks for my tank in June and love all of the life that is now in my tank because of it!

Today, when I was feeding my tank, I noticed a small crab that I imagine hitchhiked in on the TBS live rock (although, of course, I cannot be 100% certain of that, but I do not have another theory as to how it got in there). I was able to catch it and would love help IDing it (see pictures below).

Description:
  • Body: Smooth, flat and wide with three rounded edges—one at the front, two at the sides.
  • Color: Top ~¾ of carapace is blackish-blue, lower margin lighter.
  • Legs & Claws: Mostly white.
  • Claw Tips: Just the very tips are black.
  • Size: Smaller than my pom-pom crab.
  • Behavior: Found hiding under a rock (came out to grab some frozen shrimp pieces)
9DE2505B-CF39-417C-BCFF-01D643B4C46F_1_105_c.jpeg


7E6A36C4-ED10-4BE8-94E5-D75329144E0F_4_5005_c.jpeg

F1DDDB1B-CD9A-4F37-B637-797328322A28.jpg



I have not been able to ID it and would love to hear what you think it is!
 
Last edited:
Hey Everyone!

I got TBS live rock @LiverockRocks for my tank in June and love all of the life that is now in my tank because of it!

Today, when I was feeding my tank, I noticed a small crab that I imagine hitchhiked in on the TBS live rock (although, of course, I cannot be 100% certain of that, but I do not have another theory as to how it got in there). I was able to catch it and would love help IDing it (see pictures below).

Description:
  • Body: Smooth, flat and wide with three rounded edges—one at the front, two at the sides.
  • Color: Top ~¾ of carapace is blackish-blue, lower margin lighter.
  • Legs & Claws: Mostly white.
  • Claw Tips: Just the very tips are black.
  • Size: Smaller than my pom-pom crab.
  • Behavior: Found hiding under a rock (came out to grab some frozen shrimp pieces)
9DE2505B-CF39-417C-BCFF-01D643B4C46F_1_105_c.jpeg


7E6A36C4-ED10-4BE8-94E5-D75329144E0F_4_5005_c.jpeg

F1DDDB1B-CD9A-4F37-B637-797328322A28.jpg



I have not been able to ID it and would love to hear what you think it is!
Howdy,
My how time flies, sorry to have missed this thread! Did you end up sumping the little crab?
J calls these guy's mud crabs, much like a gorilla, they do best in the sump.
Rock on.
Wen
 

WHAT PART OF LIVING WITH A REEF TOOK YOU BY SURPRISE?

  • How much space the supplies and equipment take up

    Votes: 8 53.3%
  • Salt creep, spills, and cleanup outside the tank

    Votes: 2 13.3%
  • Planning trips or finding someone to care for the reef

    Votes: 5 33.3%
  • How attached I’d get to individual animals

    Votes: 2 13.3%
  • Making decisions when there’s no clear right answer

    Votes: 3 20.0%
  • How much the reef affects everyday household life

    Votes: 5 33.3%
  • Nothing in particular, I felt well prepared

    Votes: 0 0.0%
  • Other (Post in the comments)

    Votes: 1 6.7%
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