Pistol shrimp killing fish?

[ZanaZoola14]

Hello,

The latest introductions to my tank are a hi fin banded goby and what was meant to be a randalls pistol shrimp.

While the two have paired, myself and other reef keepers have decided its colours and patterns are much more tiger like — especially with how large it is. (I have attempted to attach a video, appologies about how dark, it was the only video I could get of him).

Since adding, within days, I have not seen my pink scooter blenny, Pinky, my ycg, King. As well as this, my snails are much less active (some even seeming to be missing). My firefish, Hook, while previously not the most brave of fish hardly came out and spooked from even the slightest of things. My tuxedo urchin, Talon, has also had a change in behaviour, one of these being dropping the kenya tree he has been carrying for over a month since I first got that tree. The cleaner shrimp, yet to be named, has also changed places in the tank to the otherside away from the den entrance.

It has really worried me this change in behaviour and disappearance of my two fish (they are my favourites, one being my first sw fish), and I really don't want them gone.

They didn't turn up for feeding which was their favourite time — and the cleaner shrimp was skittish as well with the food.

There were a lot of clicks and snaps, and this morning Hook had a dazed look after I heard a rapid fire of snaps, he possibly also looked to have an injury although I have not managed to get a clear shot of him.

Has anyone had similar experiences? Should I be pulling this tank apart to get to the shrimp?

Any comment and help greatly appreciated, thanks.

 

[JayM]

Looks like a Tiger Pistol to me. If it is, there's little to no chance that it's killing anything. They just aren't known to do that.

I know it's purely anecdotal, but I have two firefish that often sleep in the same burrow that my Tiger Pistol and YWG reside in. I've also witnessed the shrimp drag smaller snails into his lair, but they always emerge unscathed within a few minutes.

 

[legionofdoon]

Looks like the tiger pistol I had. They are psychopathic murderers. Mine killed anything that came near his burrow except the watchman. Snails, hermits, sand sifter star, cleaner shrimp, emerald crabs and even a poor Mandarin fish. I hated that thing and giggled when it finally died. The worst part is he'd move his burrow about every two months.

 

[legionofdoon]

Looks like a Tiger Pistol to me. If it is, there's little to no chance that it's killing anything. They just aren't known to do that.

I know it's purely anecdotal, but I have two firefish that often sleep in the same burrow that my Tiger Pistol and YWG reside in. I've also witnessed the shrimp drag smaller snails into his lair, but they always emerge unscathed within a few minutes.

Calling shenanigans mine was horrible!

 

[ZanaZoola14]

Looks like a Tiger Pistol to me. If it is, there's little to no chance that it's killing anything. They just aren't known to do that.

I know it's purely anecdotal, but I have two firefish that often sleep in the same burrow that my Tiger Pistol and YWG reside in. I've also witnessed the shrimp drag smaller snails into his lair, but they always emerge unscathed within a few minutes.

Looks like the tiger pistol I had. They are psychopathic murderers. Mine killed anything that came near his burrow except the watchman. Snails, hermits, sand sifter star, cleaner shrimp, emerald crabs and even a poor Mandarin fish. I hated that thing and giggled when it finally died. The worst part is he'd move his burrow about every two months.

Ok, thanks. So it is the tiger I really didn't want. I really hoped it wasn't but the second I spotted it I thought it was one.

That is two different opinions? Wouldn't harm and will just kill.

I don't know what to do with it. I could balance my aiptasia tank and stick him in there until I can take him somewhere.
I feel like I should give him that benefit of a doubt, especially if one says they don't. But the evidence is stacked against him. I wasn't 100% on the shrimp, but I wanted a buddy for the goby.

 

[JayM]

Ok, thanks. So it is the tiger I really didn't want. I really hoped it wasn't but the second I spotted it I thought it was one.

That is two different opinions? Wouldn't harm and will just kill.

I don't know what to do with it. I could balance my aiptasia tank and stick him in there until I can take him somewhere.
I feel like I should give him that benefit of a doubt, especially if one says they don't. But the evidence is stacked against him. I wasn't 100% on the shrimp, but I wanted a buddy for the goby.

From what I understand, there are certain pistol shrimp that look very much like a tiger that have been known to kill small fish and inverts. I'm not familiar enough to tell the difference even if your video was crystal clear, but it's a possibility that that's what you have going on.

 

[ZanaZoola14]

From what I understand, there are certain pistol shrimp that look very much like a tiger that have been known to kill small fish and inverts. I'm not familiar enough to tell the difference even if your video was crystal clear, but it's a possibility that that's what you have going on.

Ok thanks, so I might have really lucked out with this shrimp then. This shrimp, although the video doesn't show it, does have a slight orange tint to it, or is that normal tiger colours alongside the brown/black?

 

[legionofdoon]

Wait til lights out then use a red lens, you might catch him in the act. I could hear mine popping when he was on a spree.

 

[ZanaZoola14]

Wait til lights out then use a red lens, you might catch him in the act. I could hear mine popping when he was on a spree.

With only Hook left in the tank (who hides away at the back in his own burrow) it might be a little more difficult to do so. Especially as it seems that his burrow has theirs slightly connected/they made his smaller.

 

[JayM]

Ok thanks, so I might have really lucked out with this shrimp then. This shrimp, although the video doesn't show it, does have a slight orange tint to it, or is that normal tiger colours alongside the brown/black?

I have no idea, but if you can post a good pic under white lighting, @ISpeakForTheSeas might be able to pop in and get you an ID.

​

 

[ZanaZoola14]

I have no idea, but if you can post a good pic under white lighting, @ISpeakForTheSeas might be able to pop in and get you an ID.

​

I don't really have any good photos, under blue or white. He was hard for my phone to capture apparently. I'll post what I do have and I'll attempt to get more once the lights go back on in the morning. So my photos are mostly blurry, especially with the bag, but I'll attempt again tomorrow if he comes out.

 

[Keko21]

All my pistol shrimps have been model citizens. Im always a bit skeptical when people say their pistol killed anything. They have a water jet to deter other inhabitants away not a Glock.

 

[Outlaw Corals]

Yes bro definitely, I’ve had many similar experiences over the past 7 / 8 year’s with this bull’s-eye pistol shrimp i have, I call my tank, the Bermuda triangle, because since I’ve had him numerous numerous of my fish have just mysteriously disappeared, and I have a mesh lid on the tank so they are not jumping out, as a matter fact just last Tuesday I put a small mystery Wrasse in the Bermuda triangle and I haven’t seen him since, I used to hear him popping off all the time day and night, but for some reason the last two months, I haven’t heard anything from him I just see him come out when I feed the fish, he will come out a little bit from the rock work and try to grab a piece of food, the tunnel work that he’s done under the rock work is pretty wild. He has openings all over the place.

 

[ZanaZoola14]

All my pistol shrimps have been model citizens. Im always a bit skeptical when people say their pistol killed anything. They have a water jet to deter other inhabitants away not a Glock.

When reading it previously I did doubt the horror stories. But now it seems they might actually be true. I don't know what else might have caused it.

 

[ZanaZoola14]

Yes bro definitely, I’ve had many similar experiences over the past 7 / 8 year’s with this bull’s-eye pistol shrimp i have, I call my tank, the Bermuda triangle, because since I’ve had him numerous numerous of my fish have just mysteriously disappeared, and I have a mesh lid on the tank so they are not jumping out, as a matter fact just last Tuesday I put a small mystery Wrasse in the Bermuda triangle and I haven’t seen him since, I used to hear him popping off all the time day and night, but for some reason the last two months, I haven’t heard anything from him I just see him come out when I feed the fish, he will come out a little bit from the rock work and try to grab a piece of food, the tunnel work that he’s done under the rock work is pretty wild. He has openings all over the place.

Ok, thanks. So more people have had similar experiences. I think I'll give him tomorrow to see if the others appear again (and to lower the salinity in the other tank), then I make the call as to move him.

 

[resortez]

I dealt with a very similar scenario years ago but I can’t remember the type of pistol shrimp that I had. The pistol’s natural behavior is to protect the den from intruders, so by design, it’s highly possible the pistol is wrecking havoc.

 

[ZanaZoola14]

I dealt with a very similar scenario years ago but I can’t remember the type of pistol shrimp that I had. The pistol’s natural behavior is to protect the den from intruders, so by design, it’s highly possible the pistol is wrecking havoc.

Thanks, Pinky loves the sand especially close to the rock work where the den is. And King liked perching near Pinky.

So that might be likely.
But that also means that Hook has a ticking time clock now, as his den and theirs partially connects (hence his dazed expression this morning after getting to nosy).

 

[Stomatopods17]

Shower thought; I wonder how plausible it'd be for a goby to be aggressive and send 'kill that fish' signals to the pistol.

I'd actually believe in a goby holding the shotgun at everyone that goes on its lawn than the shotgun shooting itself at anything. Pistol shrimp are very docile typically.

 

[ZanaZoola14]

Shower thought; I wonder how plausible it'd be for a goby to be aggressive and send 'kill that fish' signals to the pistol.

I'd actually believe in a goby holding the shotgun at everyone that goes on its lawn than the shotgun shooting itself at anything. Pistol shrimp are very docile typically.

Maybe. Is an interesting thought. Some gobies are territorial, why wouldn't these shrimp gobies be territorial of their dens.

The shrimp is just the shotgun or pistol of the goby. It is already said the shrimp "listens" to the goby about danger. Wonder if it could say kill that fish instead of hide.

King might have been killed for being a goby, and Pinky because she was eating the copepods the hi fin seems to love.
Hook smacked for poking his head in the wrong hole.

I think this will be stuck in my head now for a while about this possibility.

 

[ISpeakForTheSeas]

I have no idea, but if you can post a good pic under white lighting, @ISpeakForTheSeas might be able to pop in and get you an ID.

From what I understand, there are certain pistol shrimp that look very much like a tiger that have been known to kill small fish and inverts

Yeah, there are actually quite a few Alpheid shrimp that look superficially similar to the Tiger Pistol Shrimp, Alpheus bellulus (such as A. rugimanus, which I've seen stores starting to sell as Tiger Pistol Shrimp recently) - some of them may not be as peaceful as it is (some Alpheus species are confirmedly not reef-safe, I haven't looked much into how safe ones that may resemble A. bellulus are though).

OP, if you can get some clear pics of the top and sides of the shrimp under white light, I may be able to ID it for you - as is, I will say I'm doubtful that's an A. bellulus, as the pattern looks slightly off on the top (particularly by the head), and I can't see the typically fairly ornate patterning on the sides (there is some variation in the pattern/color to these shrimp, but yours still looks off from all the variations that I'm familiar with from what I can see).

Pistol Shrimp tend to get a really bad reputation that (from what I can tell) isn't really deserved. A true A. bellulus or A. randalli (the Randall's Pistol Shrimp) should be peaceful/defensive - they really shouldn't go hunting at all.

Bit of an info dump here:

To clarify here, the genus Alpheus that pistol shrimps come from has some debate going about if it should be one genus or be split into three at the moment.

It's possible that some of the species (likely ones that would be put into a separate genus than the goby-pairing species if the genus were split into three) are more predatory hunters (which would probably prefer only hunting pods and the smallest of fish and inverts), but by all accounts I can find, the goby-pairing ones seem to be almost entirely defensive/territorial rather than aggressive/predatory - the goby-pairing ones seem to be omnivorous scavengers. The only evidence of "predation" I've seen involved a cleaner shrimp harassing the pistol shrimp at the end of the pistol shrimp's burrow. In fact, I've heard of multiple cases of the goby bringing the shrimp a small snail or hermit, the shrimp bringing it inside, and the snail/hermit crawling out of the burrow unharmed later.

As stated, these guys really aren't the vicious hunters they're made out to be.

They're actually omnivores (see the quote below), and the tiger pistol (Alpehus bellulus) is one of two species so far (Alpheus randalli being the other - see the link in the quote below) that has been confirmed to feed on its goby partner's feces,* so adding a goby may very well help on the off-chance that your shrimp actually is being aggressive:

A quick note here on pistol shrimp diet - pistol shrimp do not seem to be predatory, rather they seem to be more opportunistic, omnivorous scavengers (the only "hunting" that seems to take place outside of the burrow is done by the gobies, not the shrimp, and - to my knowledge - no one has ever confirmed if the shrimp actually eat the "prey" brought to them by the gobies; it might be that the goby eats them rather than the shrimp, or the shrimp might eat them as people generally assume):

Goby and shrimp associations: more than meets the eye - Coral Reefs

link.springer.com

Some more info from the article linked in the quote above:

"Diet analyses of shrimp associates indicate copepods, interstitial matter, and seagrass as main food items. Incidental observations revealed a more varied diet, facilitated by goby associates. Cryptocentrus cinctus and C. singapurensis [= C. leptocephalus] were previously reported to introduce items such as algae and bivalves into burrows for associate shrimps. We observed the goby, Amblyeleotris latifasciata, capturing a small crab near the burrow entrance and carrying this prey item toward the burrow entrance. Upon arrival, it rapidly moved up and down, a characteristic behavior we can best describe as ‘jumping’. The shrimp emerged from the burrow and proceeded to remove the entire prey item from the mouth of the goby, without resistance or struggle from the latter, before retreating into the burrow (Fig. 1)."

Additionally, as noted in the article linked above, at least some Alpheus spp. clean their gobies by eating the parasites off of them.

*Source:

https://www.researchgate.net/publication/312094089_A_novel_aspect_of_goby-shrimp_symbiosis_gobies_provide_droppings_in_their_burrows_as_vital_food_for_their_partner_shrimps

Is anyone here actually aware of a case (preferably confirmed by video and/or scientific study) of a goby-paired pistol shrimp (or even one not paired) actively hunting? Because the only confirmed case I can find at the moment is one of an apparently unpaired pistol shrimp killing a cleaner shrimp that came right up to the front of the pistol's burrow.

Between the fact that I can't find any verifiable evidence of these shrimp actively hunting and the fact that their primary diet is thought (with at least one study's worth of supporting evidence) to be their goby partner's feces*, I'm strongly inclined to believe that these shrimp basically go out of their way not to kill most things (but they will defend their territory - i.e. their burrow). So, personally - unless someone has verifiable information that says otherwise - I would guess the odds of a pistol shrimp taking out two fish (including one that is relatively large) while they are not actively encroaching on it's burrow and while it has access to it's primary food source are extremely low. That's not to say it couldn't happen, just that it seems incredibly unlikely.

*Here's the link to the study referenced above:

https://www.researchgate.net/publication/312094089_A_novel_aspect_of_goby-shrimp_symbiosis_gobies_provide_droppings_in_their_burrows_as_vital_food_for_their_partner_shrimps

Them not being paired is one of the few reasons I could see for them potentially hunting, but if that were the case here, I would expect to see some damage to the fish from the shrimp feeding (or attempting to feed) on it. Given how most animals I’m aware weigh the risks of a hunt, I can’t imagine a pistol shrimp lacking its primary food source going after a large and potentially dangerous fish to just not eat it (very few animals hunt for sport in my experience).

Personally, I’d guess there’s something else at play here - internal parasites, something off with the water quality, electricity in the water column, etc. In most cases, stuff like that would seem way more likely to me than a rogue pistol shrimp hunting potentially deadly prey for the thrill of it.

Pistol shrimp are known to gather and eat macroalgae and seagrasses on occasion - the OP on the thread below caught their pistol doing this on video:

Repetitive clicking from Aquarium? SOLVED

Hey yall i thought i would share a fun little bit on my Monday. Started lastnight around dinner time. Click click click click, almost rhythmically. So i assumed a pump, mp10 somthing. Clean pump, clean mp10, clean skimmer About to go to bed, again clicking. Happening almost evey 5 minutes or...

www.reef2reef.com

Anyway, OP, to try and rule out other potential causes: Are any of the fish exhibiting other issues - things like fast breathing, white spots on the body, etc.?