Inverts dying unexplainably

[jdmneon]

hey I just had one scarlet skunk cleaner shrimp and a sally-lightfoot crab die in my tank, they looked healthy as can be and died within a week of one another, when the sally-lightfoot died I saw the pom-pom crab on top of him, it wasn't clear what he was doing and I couldn't identify the cause of death. I can't overstress the fact that they looked the healthiest I had ever seen them the day before they died, each time a nassarius snail was eating the body but I sincerely doubt that they had anything to do with the death

things I know are in my tank
3 Nassarius snails
1 pom pom anemone crab
1 clownfish
1 black-striped cardinal fish
10 Tubastrea snails
i've got a Crocea clam, and seven LPS and soft corals.
1 barely visible serpent starfish
bristleworms, tube-worms, mini-sponges, microfauna...etc

now before you ask all the water parameters were fine, I have high-end power compacts but that shouldn't matter for a crab and a shrimp.

I think its either the pom-pom crab or something else that I don't know is in my tank such as a mantis-shrimp, however the body's weren't eaten so that kinda rules that out, does anyone have any explanations?

 

[Len]

Mantis shrimp or pistol shrimp are possibilities. Do you hear any clicking noises, especially at night? Were you able to recover both bodies? Other then that, any other changes to the tank recently?

Seems like this week is a bad week for unexplained deaths

 

[jdmneon]

the body's were indeed recovered, although both times it was clear that they had died several hours ago, the sally-lightfoots upper half seemed disconnected from its lower half and the shrimp was in pieces (although possibly from snails and the starfish and other scavengers). These were VERY healthy specimens, I had seen both eat like they were ravenously hungry the night before they died....

two weeks ago I got two new LPS corals but both came on relatively small rocks and in clearly visible bags, it is highly and I stress highly unlikely anything was on either of the rocks, and the pom pom crab is also a relatively recent addition although its about half of the size of either the crab or the shrimp.....

there are not and have never been any clicking noises, believe me I'm more puzzled than you are

 

[blackcloudmedia]

You say the upper half was disconnected from the lower half....were they moltings? Molted shells often confuse owners into thinking the animal is dead.

 

[jdmneon]

no both were definitely body's they all had guts coming out of them...

 

[Len]

Did they die in the relatively same location? If so, you may have a predator in there such as a mantis (which could shred small crustaceans into pieces).

I also thought there was a good chance these are just molts.

 

[WRASSER]

hows you salinity?

 

[jdmneon]

yes they died in the exact same location... under a bridge of rocks and on the sand-bed, I found this suspicious as well, but wouldn't a mantis or pistol shrimp have eaten my coral by now? there are many corals in that exact location that haven't been touched?

I'm not sure but I haven't seen my pom pom crab for a while and I fear the worst... I'm not going to buy any more inverts until I figure this out.

my salinity is 1.022....

is there any way I can check for a mantis shrimp and/or pistol shrimp, or do you have any other idea's concerning this matter?

 

[extremepb319]

I dont have much experience with this but you could always try setting a trap and see if you get anything? i would say its a mantis shrimp or something fast because i know sally lightfoots are not slow crabs.

Good luck and sorry about your inverts...that would be really annoying