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
 

WHICH PART OF YOUR SETUP IS HARDEST TO REACH OR REMOVE FOR ROUTINE MAINTENANCE?

  • Glass behind or beside the tank

    Votes: 8 33.3%
  • Powerheads or wavemakers

    Votes: 2 8.3%
  • Sump or rear filtration chambers

    Votes: 3 12.5%
  • Skimmer or other filtration equipment

    Votes: 1 4.2%
  • Overflow or plumbing

    Votes: 6 25.0%
  • Lights or lids

    Votes: 0 0.0%
  • Mine is pretty easy to access!

    Votes: 3 12.5%
  • Other—tell us what I missed

    Votes: 1 4.2%
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