mantis or crab?

[bcjm]

I bought a feather duster cluster side of a golf ball. Today I moved the cluster to a new spots. Few minutes later I noticed the ball moved towards the inside of a rock. I thought it was because the water current. I used a tool to grab the ball trying to take it out of the cave. While taking the ball out, I saw a blue/green claw right behind the cluster. I was sure it is a mantis shrimp or crab.

 

Questions:

1. Do mantis shrimps really make snapping sounds? I hear the sound often but I don't know where it comes from.

2. How often do mantis shrimps eat small fish or hermit crabs? My fish and hermit crabs seems fine.

3. How often do mantis go out in day light? I have never seen it in my tank.

[sportzfish]

I have no answers but am wondering where did he come from?

[WaterDog]

I bought a feather duster cluster side of a golf ball. Today I moved the cluster to a new spots. Few minutes later I noticed the ball moved towards the inside of a rock. I thought it was because the water current. I used a tool to grab the ball trying to take it out of the cave. While taking the ball out, I saw a blue/green claw right behind the cluster. I was sure it is a mantis shrimp or crab.

 

Questions:

1. Do mantis shrimps really make snapping sounds? I hear the sound often but I don't know where it comes from.

2. How often do mantis shrimps eat small fish or hermit crabs? My fish and hermit crabs seems fine.

3. How often do mantis go out in day light? I have never seen it in my tank.

1. Some do I think

2. Sporadically. We caught one once and at first it was fine in a tank with other snail, then it ate them so it got put in the tank with the stone crab

3. Not sure, but assume not often as I think they're bottom dwellers

[bcjm]

I have had my LR for many years. I did get few rocks from other people about 2 years ago but they were in a tub with no heater or circulate for a month or two. I don't expect any crab or mantis shrimp can survive in that environment.

[Coral Hind]

Could it have been the claw of an emerald crab? Did you add any of those to the tank?

 

Mantis shrimp don't really have claws, just paddles that I am aware of.

[bcjm]

It was blue/green in color. Definitively not emerald green color.

[WaterDog]

It was blue/green in color. Definitively not emerald green color.

This kind of blue-green?

http://www.trekearth.com/gallery/Asia/Malaysia/East/Sabah/Sandakan/photo305173.htm Or this kind of grayish-blue-green?

[davelin315]

Stomatopods (mantis shrimp) do not have claws per say. They have modified raptorial appendages in one of two forms - either club or a spear. Neither of these is used to grasp prey, they use some modified "legs" if you will around their mouth to do this. These are more for grasping than for anything else and when it is holding onto something, it's body is easily visible because it holds these beneath its head.

 

The only mantis shrimp that make a clicking noise are the smashers, which are the ones with the club appendage. The spearers do not make any noises like this. What my guess is is that if you are hearing something, it's most likely a pistol shrimp. The pistol shrimp do have claws to grasp with and will also make a snapping sound. The likelihood of it being a mantis if you saw it holding onto the feather duster is very unlikely as you would have seen the rest of it. Also, emerald crabs vary greatly in color and can change from molt to molt, as can many other crabs out there.

[bcjm]

OMG it is a pistol shrimp!!! I was grabbing a frag near a rock using a tweezers. The shrimp came out attacked the tweezers and making a snapping sound. I bought this shrimp with a yellow watchman goby together about 6 months ago. I only saw the shrimp on the first day. I thought the shrimp never made it. Now it is huge lives under a rock. It has blue/green/red on the body. Not sure if it is going to get bigger and pose a danger to other animals in the tank.