What are these things? They creep me out!

[kllyjansen]

I have had my little 5 gallon set up for about four months now and I'm surprised at the amount and size of the creatures coming out of the live rock at feeding time today.
First: A little brown lobster thing about one inch long shot out of the live rock today, grabbed some of the brine, and shot back in again. I have no pic because he was too fast and I haven't seen him since. He had two claws and a lobster-like tail. My boyfriend said it could be a mantis shrimp? Ich.
Second: I found this guy moving around today too. He won't come all the way out of the rock for a good pic.

Finally, for now, I have a bug looking thing in a hole. The best pic I have is terrible, but maybe someone will have an idea anyway:

 

[bang guy]

#1 = Stomatella varians. This is a very beneficial snail that eats Diatoms.
#2 = Vermetid Snail. This is a quasi-beneficial snail that eats detritus. I say quasi-beneficial because the tentacles and slime it produces can irritate corals if there's a lot of floating material in the water column.

 

[kllyjansen]

Better pic!

I'm amazed it's been in there for four months without detection. It's a small tank and I have studied it daily.

 

[renogaw]

lobster thing may be a mantis shrimp

 

[oceanlover]

Do you have acopora or other SPS? My girlfriend has little brown lobster like things that live in her hard coral and they are not mantis shrimp.

 

[fenrir]

It could also be a pistol shrimp which are perfectly safe.

 

[joezimm]

Originally Posted by kllyjansen
http:///forum/post/2823100
I'm amazed it's been in there for four months without detection. It's a small tank and I have studied it daily.
I have one of those also. Like you, it just seemed to appear after months of not adding anything in the tank.
I noticed mine when it was just a tiny little spec zipping across my LR one night. I say 'zipping' cause i've never seen a snail move as fast as this thing

. I didn't see it for about a month. Then the next time it showed up it was about the size of yours. Hasn't grown in a couple months since then. It's still pretty fast when it wants to be.

 

[socal57che]

Originally Posted by renogaw
http:///forum/post/2823675
lobster thing may be a mantis shrimp
Or a lobster. There are a few that are seen in the aquarium trade.
Red Hawaiian Lobster.
Purple Reef Lobster.
Blue Spiny Lobster.
Daums Reef lobster.

 

[joezimm]

Originally Posted by socal57che
http:///forum/post/2830515
Or a lobster. There are a few that are seen in the aquarium trade.
Red Hawaiian Lobster.
Purple Reef Lobster.
Blue Spiny Lobster.
Daums Reef lobster.
I would agree. If you could see that it had claws, I wouldn't think it is a mantis. Mantis don't really have 'claws' to speak of, just their hammers.