If you arent worried about them slowly taking out your cleanup crew and arent gonna keep any slow moving fish I would say that they are reef safe. They will move anything they can and break up your live rock but generally the species you are talking about if kept pretty well fed would do fine in a reeftank. I have kept one of the same kind with hawkfish and damsels and they leave them alone. They will not eat your corals but may knock them over. I would seriously consider that if u really want to keep one that you dedicate a small acrylic tank for it ie: one of the eclipse tanks would do well. I kept one for two months in my 20 gal reef and it killed and ate about 20 snails and hermits. So basically they will eat snails and hermits, rearange the whole tank, possibly (although pretty rare) break glass, bulldoze, and catch any slow moving fishes. Other than that they are one of the most interesting of all creatures, always active, and pretty intelligent so I would say get a small eclipse 6 or better yet 12 and get that mantis before it is gone because they arent very easy to find! It will accept any meaty food and actually become quite used to you coming out when you are near to basically beg for food.
I responded to your mantis post on the reef board before checking to see if you had found this one. Anyway, if you decide to NOT get the little guy, I'd appreciate if you'd tell which store has him. I'd love to get another one - the one I have now is in a tank I keep at the office & I want one at home as well.
BTW, Noidster is COMPLETELY WRONG about mantis - they're stupid, boring & you never see them...and they will break out of the tank & kill your favorite child or pet. Basically, you don't WANT it...so ummm...just tell me the name of the store & spare yourself alot of grief.
Anyyyyway - here is what I posted on your other post:
I've had a 3" mantis (named Grendel after moviegeeks' Grendel(RIP). in a small reef (containing only shrooms & small leathers) for approx. 4 mths now & he's been fine. The only downside is that they will eat your cleanup crew
There was a similar question
posted several months ago on AL & as someone was insistent that they will eat corals, I emailed Dr. Roy Caldwell (he's at UC Berkeley & considered a stomatopod authority). In a nutshell, he said they will not eat or harm corals other than those that might get in the way when a smasher type is breaking up LR to do home improvements.
They're totally fascinating & intelligent critters - make sure you visit the links posted by Pegasis, especially the first one (THE stomatopod site - awesome info, pictures & stories).
PS: Mantis are evil - EVIL I TELL YOU (just tell me the store name & you will sleep better - trust me.)
i kept my mantis with a anenome and 4 hermits for 2 months at least.
he only killed 1 hermit which was the smallest and he only did that because i forgot to feed him for a day or two. ( maybe a week ? )
follow noidsters ideas and get an eclipse tank and get into it.
you will want to buy more and more of the little critters when you finally realise how wicked they really are.
i kept my first one in an eclipse 6 until i wanted more space for him to build and muck around.
ive fallen head over heals and ive just bought 2 custom made tanks so i can get more.
go get one,
p.s - eclipse tanks are awesome for keeping venus fly traps in and thriving.
I plan on setting up a 90g reef tank myself. My O. scyllarus will be in this tank after I get it up and running. I do plan on taking some steps to prevent the O. scyllarus killing my corals though. What I plan on doing is keeping all corals off the bottom layer and substrate, only allowing coralline algae growth. I also plan on creating my own live rock pieces that will build a caving system for My O. scyllarus, by doing this I hope to prevent My O. scyllarus from breaking up live rock that any corals would be on. I am not too worried about My O. scyllarus killing any snails, hermits and other fish. My O. scyllarus just eye balls them and don't do anything more. Right now I have two black mollies, which were cycling fish only, two scarlet hermit crabs. To this day they are still in there. In fact My O. scyllarus will actually grab my hermits and use them to reinforce its den walls without hurting them. The hermits at night just walk away and do there normal routines after being placed by My O. scyllarus. Which seems to be abnormal for a smasher.