Strange creatures! HELP

Hi, got two problems! well I'm in the 2 phase of my nitrogen cycle, and i decided to put macroalgae in my refugium! i went to my LFS and bought some.. now i was looking at my tank and all my glass is filled with tiny white creatures also they walk on my substrate! and i was trying to see if they were on my LR when suddenly,,, i never seen such thing!! something came crawling out of the LR it looked like something close to a shrimp that mated with a centipede,, and crawled back inside another hole i kept looking at the same rock but it didnt come out again! also there are some long white tubes in the substrate, at first i thaught it was the 2 damsels waste but its bigger and longer and white! any ideas these things are! are they helping the cycle? are they part of the cycle?

 

dont worry, they are just a type of pod. chances are they are good and you wont have any problems with them. but to help out pic...post some

 

I was thinking mantis shrimp too. long white tube might just be fether duster worms. Pics will be helpfull if you can get them

 

ok well! tiny white spots are copepods,, now thanks for the tip of the mantis shrimp but i have searched pics and it looks more like this large amphipod, let me try to post some pics if i can catch him out of the LR again, but i will paste the pics of the tubes!

 

El

I have gotten at least 4 mantis shrimp and two pistol shrimp in my new live rock. I have been successful at removing the shrimp by taking out the suspected piece of rock (inspect the rock for snails and such first) and pouring soda water over it. If you listen for the clicking noise you may be able to figure out where they are at, or you may see molting left behind.

I have read that the mantis are also called "thumb splitters" you don't want any hand to hand combat with these, you will lose! From reading the boards it is controversial whether or not mantis pose a threat, I just didn't want to take a chance.

Good luck

 

that shrimp thing is prob an amphipod - agin good for the tank and serves as supplemental food

 

If the "shrimp that mated with a centipede" thing is anything longer than like 1/2" then it's probably a mantis. If it's small, then it's an amphipod. Amphipods are good for the tank, though they usually don't last long since the fish eat them pretty fast.