Tiny Mantis-like shrimps

[Anonymous]

My tank is a 100 gal tank with 6-8 inches of live sand from various source include sand from the Gulf of Mexico. I found a bunch of small custaceans that is very much like mantis shrimps in the sand, burrowed in the top two inches of the sand. These custaceans are about .75 cm in lenth and .1 cm wide. They come with mantis claws just like the real thing. There are about 18-20 of these burrow along the 4 feet front of my tank. What are these animals. Please don't tell me that I have baby mantis in my tank. I do have an 4 inches mantis shrimp in my sump(about 6 inches of whole oyster shell that I use to give shelter to various animals in the sump, and to attach new coral divisions on). TIA

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Minh Nguyen
Visit my reef at:
http://sites.netscape.net/austinnguyen/homepage

 

[Anonymous]

Minh,

I have these same critters. I believe they are a 'pod of some sort (isopod, amphipod) which serve valuable nutrient processing and sandbed aerating functions. Good critters, IMO.

Kevin

 

[Anonymous]

Mihn,

Take a close look at the claws. If they have pincher or tweezer like claws, they are not mantis shrimps. If the claws close back on themselves like a jack-knife blade then they are indeed mantises.

From your description of their habits, though, I would be willing to bet they are not mantises, but animals called "Tanaids." These are closely related to amphipods and isopods, and really may be thought of as amphipods with claws.

I would consider them harmless, and probably beneficial. Only about 5% of the population will have have the big claws by the way, and they will all be male. Smaller animals, without claws are all females. The males can't feed (they don't have a gut) and live only a week or two as roving Romeos trying find as many mates as they can. Then they die, and the next largest females molt and change into males. Neat life cycles and pretty neat little critters.

Cheers, Ron

 

[Anonymous]

I have found a critter that you have indicated in my tank also. I have not seen him in the sand but he does pick at the LR I have in my tank. He makes a very loud clicking noise that can be heard clearly. I once saw him working at a piece of sponge that was on a rock that he typically resides. Does anyone have an idea of them being reef safe. I am undecided.

 

[Anonymous]

Minh,

After reading Ron's reply, I went searchi8ng and found a web page with a link to a pretty accurate drawing of the little buggies (technical term) in my tank.
http://info.ex.ac.uk/biology/adrianc.html

Tanaids - thanks Ron (of course, it sounds like something we fair-skinned folks might use before going to the beach

Kevin

 

[Anonymous]

Hi Kevin,

Ha! Never thought of that - Latinized or Latin words have no silent letters, so this word is pronounced Tan-A'-id or Ta-nay-id. I learned it that way and never thought anyone would pronounce it Tan-aid.

Cheers, Ron

 

[Anonymous]

Jass,

You got yourself either a mantis or a pistol shrimp!!

What color is the little monster?

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In Heaven there is no beer, so we have to drink it all here!!!!

 

[Anonymous]

jass411,
What you found in your tank is either a manits or a pistol shrimp. The tanaids we are talking about are tiny, only .75 cm in lenght full growth.
Ron,
I will see if I can take one to work to look at under the microscope will let you know about the claws. Thanks. I know I can alway count on you.


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Minh Nguyen
Visit my reef at:
http://sites.netscape.net/austinnguyen/homepage

 

[Anonymous]

The color of this critter is maroon and it is about 1 inch long.

 

[Anonymous]

Jass,
That sounds like what I have-a mantis shrimp. I have two in a small tank on my kitchen counter ('cause they are too cool to flush) that I took out of my reef tank. My larger one is 1 1/2" and is a maroom color. Good luck trying to get them out. I was lucky to take out the coral skeleton they were hiding in and got them out that way.

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So long and thanks for all the fish...

 

[Anonymous]

Got the little bugger out. Did not have a bad time at it either. Thanks for all of your help in identifying this menice.