How to catch a Gorilla Crab and MORE.

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This thread is for the general discussion of the Article How to catch a Gorilla Crab and MORE.. Please add to the discussion here.

A tried-and-true method to easily trap a rogue crab.

Trap Undesirable Hitchhikers with a GLASS glass.

• flashlight
• tall glass glass
• frozen clam
• fish net

Using bait that floats? Trying to catch a shrimp? Make these adjustments to the trap:

• shrimp tails, silversides, krill
• secure plastic wrap to top of glass with a zip tie or rubber band (retaining light weight foods and preventing shrimp from propelling out)
• cut a 1" slice in the middle of the wrap

First, spend time observing the tank while the lights are on and while the lights are off. Specifically observing rock surfaces; the nooks and crannies, top, sides and what you can see of the back. Be sure to investigate the crease where sand and rock meet. Once you set eyes on the offender and its location, move to the next phase. Initiate the trap when there is little to no lighting. The benefit of nighttime trapping is you are far more likely to catch the predator. *Wait to set the trap until the tank has been dark for a few hours.

Choose a tall glass with a heavy bottom and drop in a frozen clam.
The glass needs to be tall so the crab cannot stretch out and reach the edge. A frozen clam works very well for this application as it is heavy and as it thaws the clam will open advertising a lovely seafood restaurant is open for visitors. *Purchase food grade clams and keep them in the freezer.

Carefully position tall glass at a steep angle near the offender's real estate.
With tank lights off and using a flashlight or headlamp deploy the trap! Locate the glass close enough to the aquascape as to keep the angle somewhat steep. You want the crab to reach for the food, slipping down and then be unable to clamor up the tall and slick sides. Press the glass into the sand and/or secure it with a rock. (You may need turn off a power head.) Now that the trap is in place, let it soak. Don't be tempted to constantly be peering in with a flashlight. If you are looking, it ain't cooking. Check it every half hour or hit the hay for a morning surprise. *Remember to position the trap where you last saw the predator.

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WoooHOOO, easier than you anticipated, right?
Keeping the lights out, carefully remove the glass ASAP. Either lift the glass gently up using your hand to cover the opening or place a net on top of the glass. Be cautious, deliberate and mindful with your actions when working with glass in the dark. *This crab was captured within 10 minutes.

Is it a predator or a friendly?
Now that your prize is in the bottom of the glass take a few minutes to confirm its identity. Is it a predator or a friendly?
Crabs are beneficial in an ocean environment and marine aquariums, whether it be cleaning detritus or consuming dead or dying creatures.

Overflow chambers are an excellent location for gorillas as this space often accumulates detritus and uneaten fish food, same with a sump. Everyone needs a sump monster!
Have a HOB fuge? Know someone with a FOWLR or a predator tank? Crabs are great snacks for puffers, triggers, mantis and eels. How about your LFS?
Before you flush it down the toilet, pay it forward by crushing it to feed your aquarium, starfish, hermits and fish love crab too! *Photographed gorilla crab was moved to the sump.

Happy Crabbing and Rock on.
TBS​

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*this mud crab was caught overnight and released safely into the sump.

Select a tasty treat, use a tall GLASS glass, deploy after lights out, lean trap securely against the aquascape at a steep incline...
Set it before bed and wake up to a surprise. WowWee, this trap is too easy! ​

 

[revhtree Verified Admin]

Very cool! Thank you for sharing!

 

[Gumbies R Us]

Wow, I could not imagine finding one of those in my tank! Thank you for sharing how to get rid of them!

 

[Fish Fan]

This is great info for sure! I know many R2R members are hesitant to try your rocks out of fear of getting a gorilla crab, so I think this post will be quite helpful. I'm going to bookmark this to share with others in other threads.

 

[Mongo1.0]

Wish I had thought of that. Had to catch 2 crabs a while back. Had to use tweezers. They kept getting into the holes of the rock.

 

[LiverockRocks Verified Sponsor]

Wish I had thought of that. Had to catch 2 crabs a while back. Had to use tweezers. They kept getting into the holes of the rock.

This method works great especially for rouge emerald crabs, ruby crabs and gorillas.

• Night trapping works best.
• Lean glass at sharp angle where offender was last seen.
• Use a bait that sinks like clam in shell, piece of shrimp or silverside.

*If trapping a shrimp; top the trap with clingwrap secured with a zip tie or rubber band, and slice a 1" opening in wrap.