Calling all mantis shrimp experts

[Aqueous]

Greetings all,

 

I hope you don't mind if I ask a question about G. smithii behavior.

 

I received my smithii from bluezoo aquatics a month ago, it is an adult about 3.5" long---my first mantis. The first and last time I ever saw it was one month ago, when I first introduced it to the tank. After a drip acclimation, it went into the tank, perched on a rock, then promptly went into the live rock den that I arranged for it and hoped it would find. The issue is that it hasn't come out since, not once, not even a hair. It also hasn't eaten. It lives with plenty of hermits and snails, none of which I've found dead or smashed apart. I've offered krill, silversides, mysis, brine, etc. It will grab a hunk of krill and hold onto it for a bit, but then let it go. It spends its time fairly motionless in its burrow, often laying on its side. 

 

My tank is a 12" cube with live rock and several lps, mushrooms, etc. Regular hob filter from seachem, kalk dosing, ato, wavemaker,  Water quality is outstanding, kalk dosing with topoff water keeps the alkalinity and Ca levels in the ideal zones (I'd hafta look at my last readings, can't remember what the value was off the top of my head.) salinity is rock steady but 1.023, as that's what my fish store mixes it at. The tank was cycled and happily maintaining corals for some weeks before the shrimp was introduced. 

 

Now I've heard and read that these are pretty entertaining little guys, so I was a bit surprised by this. In my experience, a month is usually enough time for an invert to get comfortable and  confident in its enclosure. My first thought was that is was molting, but as I said, it's been a full month by now, and I've still seen no signs of a molt, no change in the reclusive behavior, and no still interest in food or hunting. It simply stays in its den, I've never once seen it come out, though it will barely poke it's eyeball out once in a while. I'm somewhat surprised, as I've read that in the grand scheme of mantis shrimps, these are fairly gregarious. And, since they are a tidal species, they are diurnal and thus less stressed by light. Figured it was a perfect combo! 

 

So yeah...what are your thoughts? Is it molting? Is it just a shy mantis? Is it because my salinity is on the low end of acceptable?

 

Any insight would be most valuable. 

 

-Ethan

[MrSquiggle]

1 hour ago, Aqueous said:

Greetings all,

 

I hope you don't mind if I ask a question about G. smithii behavior.

 

I received my smithii from bluezoo aquatics a month ago, it is an adult about 3.5" long---my first mantis. The first and last time I ever saw it was one month ago, when I first introduced it to the tank. After a drip acclimation, it went into the tank, perched on a rock, then promptly went into the live rock den that I arranged for it and hoped it would find. The issue is that it hasn't come out since, not once, not even a hair. It also hasn't eaten. It lives with plenty of hermits and snails, none of which I've found dead or smashed apart. I've offered krill, silversides, mysis, brine, etc. It will grab a hunk of krill and hold onto it for a bit, but then let it go. It spends its time fairly motionless in its burrow, often laying on its side. 

 

My tank is a 12" cube with live rock and several lps, mushrooms, etc. Regular hob filter from seachem, kalk dosing, ato, wavemaker,  Water quality is outstanding, kalk dosing with topoff water keeps the alkalinity and Ca levels in the ideal zones (I'd hafta look at my last readings, can't remember what the value was off the top of my head.) salinity is rock steady but 1.023, as that's what my fish store mixes it at. The tank was cycled and happily maintaining corals for some weeks before the shrimp was introduced. 

 

Now I've heard and read that these are pretty entertaining little guys, so I was a bit surprised by this. In my experience, a month is usually enough time for an invert to get comfortable and  confident in its enclosure. My first thought was that is was molting, but as I said, it's been a full month by now, and I've still seen no signs of a molt, no change in the reclusive behavior, and no still interest in food or hunting. It simply stays in its den, I've never once seen it come out, though it will barely poke it's eyeball out once in a while. I'm somewhat surprised, as I've read that in the grand scheme of mantis shrimps, these are fairly gregarious. And, since they are a tidal species, they are diurnal and thus less stressed by light. Figured it was a perfect combo! 

 

So yeah...what are your thoughts? Is it molting? Is it just a shy mantis? Is it because my salinity is on the low end of acceptable?

 

Any insight would be most valuable. 

 

-Ethan

Thanks you Ethan for a well written piece and a great question.

 

Here is our experience.  

 

Shrimpy is very reclusive.  We too thought he was dead at about week 2.  At first shirmpy would only emerge from his lair once every two weeks, we assumed when hungry. Then after about 3 months he started appearing weekly.  Again only as long as it took to have a quick explore and grab a meal and then back in for another week.  shrimpy has a lair only as large as a closed fist.  It is a reef rock that was solid and he smashed a lair out and proceeds to build a lair door every time he goes in that is hard to the touch, he essentially entombs himself.  

 

Now there was a period for about a month, say five months in (after we first got him) when shrimpy was out almost every day, always closing up for the night though.

 

When we moved house, shrimpy changed back to once a fortnight.  Now, two months in it is still once a fortnight.

 

We have a rule that if shrimpy does not emerge in a two week period we gently poke his lair in and he smacks the tongs (loud snap) ok he is alive!  We give him a lance fish tail (his favorite) and away he goes for another stint in solitary.

 

We, like you, did not expect this behavior.  We were led to believe that smithiis were of the more adventurous variety.  Not our experience.

 

I would say that it smithiis take a lot of time to become confident in exploring.  We expect in the coming months he will begin to come out daily again.

 

Right now we are battling water quality issues with green algae slowing coming under control.

 

We were over lighting the tank and also over feeding.  i now have decent water testing equip and water is improving quickly.

 

shirmpy tolerates the following fish so far, blue green chromis and clown fish.  He insta kills gobies.  We got two and they were gone in 24 hours (RIP).

 

The Chromis are too quick and upper column dwellers, and clown fish seem to "know" there is a killer around and steers clear.  They also sleep in the middle column so they are not at risk of a nighttime smacking.

 

Strangely the Chromis all sleep right near his lair at night and are all still alive!  They must sleep with one eye open lol

 

My only advice would be to put a feed near his lair entrance every few weeks and try to coax him out of the lair.  Just so he or she realizes that it is safe out.

 

It sounds like your water is fine and the tank is not the issue.  Time is what will be needed for your smithii to come out and about.  But don't fret if you have a recluse.  It only make it all the more magical when you see him or her!

 

Here is the last time shrimpy was out!  That was two weeks ago lol.

 

Please keep me updated and good luck.

 

P.S we have never seen shrimpy molt yet and suspect he does it in his tiny lair.  Amazing

 

 

 

 

 

[MrSquiggle]

This is one of the gobies that was taken that night...

 

Such a beautiful fish.  We were wrong to introduce them though and will not do it again.

 

If you look behind the gobi right at the start of the video, you can see shrimpy casing out the new intruder.  He obviously decided all the sand moving was not on and took care of the new intruders.

 

I would point out that anything you put in the tank is at risk of being killed so be careful  :)

 

[Aqueous]

Thanks so much for the input, it's funny how as much as we read and research about animal behavior, that is never a guarantee. In fact it seems that frequently that the practical knowledge we get from observation contradicts what we read and the personal accounts we hear. Then again, there are too many variables to make many conclusions there.

 

Regardless, I thank you for sharing your experience, it makes me feel a bit less crazy and a bit more optimistic, as what you've described is almost exactly what I am experiencing. I'm slowly getting the tank up to 34ppt salinity, and the good news is that the lil' fella has taken hunks of krill the past two days. In fact, I even coaxed it out of its hole and saw a full HALF of its body before it smacked the crap out of my metal tongs---I tell you what, the shock conveyed through those tongs was enough to give me pause when messing with rock work around its den. Hearing it and reading about it is one thing, feeling it another. I couldn't believe how much force that rascal can create. 

 

Anyway, I'll keep on keepin' on and try to get some pictures if  it ever decides it's ready to venture out. Sure hope so, the thing is just beautiful.

[Aqueous]

On 4/29/2019 at 9:57 PM, MrSquiggle said:

This is one of the gobies that was taken that night...

 

Such a beautiful fish.  We were wrong to introduce them though and will not do it again.

 

If you look behind the gobi right at the start of the video, you can see shrimpy casing out the new intruder.  He obviously decided all the sand moving was not on and took care of the new intruders.

 

I would point out that anything you put in the tank is at risk of being killed so be careful  🙂

 

 

Sorry to hear it, love that particular species. That said, both occupy a similar living space, and a mantis ain't havin' that...