Wennerae Mantis Shrimp fish safe?

[valley]

Hello, I have a wennerae mantis shrimp in my 60 gallon breeder that came from live ocean rocks. I’m looking to stock this tank with fish now but the mantis shrimp is sort of in the way. I’m worried that it might kill any new fish I add because of the mixed opinions I’m seeing online.

In my case, the mantis shrimp is about 2-3 inches. I haven’t really scaped out the rocks and they’re all just scattered along the sand bed so the shrimp is constantly moving between rocks and around the tank.

The live rock also carried red emerald crabs, a sponge crab, and pistol shrimp. The pistol shrimp is the only thing that died and I’m not even sure the mantis killed it. The crabs are out often during the day and night, the mantis shrimp doesn’t go after them and hasn’t hurt any of them.

I’m currently feeding it a piece of freeze dried krill once a week and I’m starting to like it. Considering all of this, is it best to get rid of it or could I just keep it? I plan on stocking the tank with peaceful and semi-aggressive fish. Some of these are small.

 

[Tamberav]

I kept fish with mantis shrimp but it’s definitely possible the mantis may eat some at some point.

They are super interesting and worth setting up a 10g for.

 

[Fish Fan]

My mantis passed away recently when an ATO malfunctioned while we were on vacation.

R.I.P., little buddy, aka 'Larry'. Sorry I screwed up :-(

That hurts to type.... But no one will learn if we all don't admit to our mistakes.

I can say from first hand experience, the N. wennerae Mantis is aggressive and will kill crabs like emeralds and hermits, and more.

But mine also would kill snails (though he liked crabs more). I never tried a shrimp in his tank, but I can pretty much guarantee that the poor shrimp would have no chance. It would be just a matter of time; poor shrimper. Fish would be much the same, I believe, just a matter of time before the Mantis decided it's had enough of this fish in my tank.....

In general, these animals are considered aggressive and not safe for fish or motile (moving) inverts. You can keep them with inverts like corals, I had some Zoas and Florida shrooms in my mantis tank. Anemones are hit-or-miss, I've been told, and can, in fact, kill the mantis. But other than that, pretty much anything you put in your tank with a mantis will sooner or later be *fun* for the mantis to kill. And if not "fun", certainly they are just very, very territorial.... But to me it seems like fun for the mantis lol!

I say that because they can and do kill animals much larger than themselves, and they may or may not eat some or all of their kill. A lot of times they burry something they've killed in the sand. I'm not sure if they are trying to get rid of it, or stash it for later, but either way, a rotting crab carcass can cause nutrient spikes in your system, just from my experience.

I think these guys are fascinating critters. I would encourage you to embrace your little spud, and maybe set him up in his own small tank. Some people keep them in their sump area, separate from their display animals. They don't need much to be happy, a 10 gallon tank, some rock and sand and rubble for them to move around and build their home, a simple HOB filter and heater. They don't even need a fancy light. They are, in my opinion, very cool critters to keep!

Occasionally, I would place an order from Reef Cleaners, who offers Clean Up Crew (CUC) critters at a very good price, with *most*, but not all, available for shipping by relatively inexpensive USPS Priority Mail, as opposed to the overnight shipping that many places want for animals, even just for hardy inverts (like a Mantis -WTFluff!). I would add a bunch of snails and hermits to my Mantis tank, and let my guy have at them as he saw fit, in addition to my hand offerings of shrimp, etc.

https://www.reefcleaners.org/

Again, please consider a super easy, super small tank that you can keep your Mantis in, or house it in your sump, if you have one. My mantis would take food like a piece of frozen table (seafood market) shrimp off tongs or forceps. If I put frozen mysis shrimp in the tank, my little spud would come to life and fly all around grabbing up the free floating bits of mysis. They are seemingly intelligent (read: way smarter than me) and fairly interactive with its keeper.

That said, if you decide a mantis is not in your plans, I am here right now to say I will take him. I want another N.wenerrae, and if you can trap him and box him and safely ship him to Upstate New York, I will pay you for your trouble and the shipping. If that's an option, please let me know, you can DM me if you would like.

But if you can see fit to keep your guy, I'm sure you'll be rewarded with a very cool animal

Best of luck with your Mantis!