Show me your Emperor's Shrimp!!

[Ben's Pico Reefing]

I can go digging through the papers I've found on these guys again tomorrow and double check, but, yeah, they likely do have similar diets to other shrimp while also feeding on their host's feces (similar to pistol shrimp with gobies, which show increased weight gain when offered the feces of one of their partner goby species; are the feces necessary? Probably not, but it might be needed for some reason or another).

Anyway, my point with the hermit crab and shell example was that the hermit's need for the shell is as much or more psychological than it is physical - that is to say, even if the crab is kept alone in a little crab paradise tank, it will still be stressed (likely to death) unless it has a shell. So, these sorts of relationships aren't always (just) about the actual, physical protection and nutrition provided by them - it seems they're also frequently about the mental protection they provide, if that makes sense.

From what I've read, that seems to be the case with these - the article below discusses it a bit:

The Emperor’s Shrimp (Periclimenes Imperator)

Periclimenes imperator (Emperor shrimp) on Bohadschia argus (Sea cucumber) via http://en.wikipedia.org One of the coolest thing about this hobby is its diversity in tank inhabitants. This is sadly its biggest problem as well. Due the the immense...

www.reef2reef.com

So, while some symbionts (such as clownfish and anemones) may not literally need each other to survive/thrive long-term, others might (regardless of if they literally physically need each other or not, they may still mentally need each other).

I did a bit more reading as well and found several instances about the feces. While lots of critters do this without hosts just because it's available. For this shrimp I am wondering if A it does this to speed up any resistances to any chemicals/defences the host has, or there is a diet benefit that it needs from this. If it's for a diet need then definitely don't want to keep without. If it's a similar relationship to a hermit crab rather than a clown fish, this would also be a no go for me as well. To much unknown and risk at the moment from what your saying and I have read to try at the moment. Thanks for the info.

 

[ISpeakForTheSeas]

Yeah I noticed the majority of people who keep them don’t even give them a proper host, Which wouldn’t be the case for my tank, I’m looking to keep it with a sea apple, which are quite large in terms of cucumbers (in reef aquaria at least) and it will probably be the only shrimp in the tank, there will be no predators to eat it. I also have the ability to spot feed it so I think it would benefit from that too.

So, proper known hosts for the Emperor Shrimp, Zenopontonia rex (A.K.A. Periclimenes imperator or Periclimenes rex) include Sea Cucumbers (Holothurians) and large Sea Slugs (Nudibranchs and Pleurobranchs specifically) - they have reportedly been found on a Cowry species before (which I forgot about, honestly) and occasionally on starfish; I question the starfish findings specifically - the cowry honestly makes more sense to me given their other hosts:

They've also be reported with a couple crinoids and sea stars, but I'm not sure I trust those reports, as Emperor Shrimp (Zenopontonia rex) often look remarkably like the Starfish Shrimp (Zenopontonia soror), and may well have been confused with them in the studies.

"The imperial cleaner shrimp is a commensal species*, living on the bodies of large sea cucumbers ( Stichophus , Bohadschia , Thelenota, Opheodesoma, Synapta ) as well as large slugs ( Pleurobranchus , Hexabranchus , Chromodoris, Dendrodoris , Asteronotus , Ceratosoma, Hypselodoris ) and gastropods ( Cyprea ). It has also been observed, but very rarely, on starfish ( Echinaster, Gomophia ). This list of hosts is not exhaustive."*

*Source (it's in French - sorry):

Zenopontonia rex | DORIS

Voir la fiche de cette espèce

doris.ffessm.fr

For what it's worth, a couple of confirmed host species are:
-Thelenota anax
-Synapta maculata

 

[ISpeakForTheSeas]

I did a bit more reading as well and found several instances about the feces. While lots of critters do this without hosts just because it's available. For this shrimp I am wondering if A it does this to speed up any resistances to any chemicals/defences the host has, or there is a diet benefit that it needs from this. If it's for a diet need then definitely don't want to keep without. If it's a similar relationship to a hermit crab rather than a clown fish, this would also be a no go for me as well. To much unknown and risk at the moment from what your saying and I have read to try at the moment. Thanks for the info.

Yeah, I don't know if it would be a dietary need (people can keep pistol shrimp without their goby partner), but I'm currently inclined to believe the host may be a psychological need.

I could be wrong, but that's my current understanding of the species.

 

[ReeferHD]

This is the only source I've found where a sea apple is hosting an emperor shrimp, and it seems to be working out for them. later on in the thread the shrimp takes to a different sea apple.

Sorry for the lack of update guys! I've been busy with the tax season / work so I've been neglecting the tank.

I did finally get the chance to clean up the tank a little bit and did some pictures though!

Some new Xmas worm rocks

My Sea Apple with his buddy. I'm getting a very special Sea Apple in soon, can't wait to show you guys!

Another Shot

Sea Cucumber invading my algae

Carnation Coral still going strong!

Nemastoma has finally started to grow more

Fauchea Sp.

I had thought this sea fan was a goner but it has stopped RTNing!

Hope you guys enjoy! I will try to get more shots throughout this week!