To Catch a Killer… Pistol Shrimp Eradication

[AlaskaMatt]

Hello Everyone,

I have recently setup my 32gallon Fiji cube with TBS Liverock. My tank has been up and running for a little over a month now and so far most everything has been running smoothly.

That is until I started to add fish. So far I’ve had a yellow coris wrasse (tiny little guy) put him in the tank and disappeared, then last week a tailspot blenny (gone without a trace), and now a purple firefish goby (disappeared the second evening). I have not found so much as a spec of their existence after they’ve gone missing and while I know two of the three of those fish are known for disappearing the yellow coris wrasse has been gone 3 weeks and the tail spot 4 days. My firefish was active and settled in and all of a sudden gone without a trace. I should mention I have a top over the tank and have checked the floor

I know my tank has a good population of pistol shrimp as I hear them snapping frequently and have caught one already (blue claw only one large one) and have seen at least one other. My plan for eradication is as follows:

1) From now until Sunday I will set multiple bottle traps in my tank baited with raw seafood (probably clams or oysters whatever is at the store).

2) if I am unable to eradicate the shrimp by Sunday I’ll pull the rock out keeping the top layer of live rock in a bucket and take the 4 rocks forming the base that are in contact with the sand out into a hyper saline solution to flush out the buggers.

I already pulled all the rock out once to catch gorilla crabs and I caught about 7 and I know there’s at least two left, but I only took the rock out one at a time and inspected it. I think the shrimp just ran under different rocks in the tank when I lifted the rocks out one at a time.

So my question for the community is if my plan sounds solid? Or would you have any recommendations or tips to help me in my journey to be able to keep fish in my tank.

 

[Timfish]

Sounds like a lot of work for an animal that isn't likely to be the problem. It doesn't sound like you have a quarantine tankso I'd suggest putting your efforts into setting one up.

 

[PicassoClown04]

Are you sure they are pistols and not mantis shrimp or Medusa worms? How did all of those hitchhikers get there? I’m assuming it’s live rock from the ocean? If so, there is a very strong chance of having bad critters that can kill sleeping/newly introduced fish especially those like fire fish that sleep deep in the rocks. Good luck with the extermination!

 

[Hungrypede]

Start with the bottle traps, all different sizes. If that’s the only food in the tank consistently for a while (longer than 5 days) I think you’ve got a good chance of catching your culprit. Let us know if it works before going to option 2!

 

[brclark82]

I would put my money on a mantis shrimp or one of the gorilla crabs before a pistol shrimp doing that damage but I suppose the plan is the same…good luck

 

[brclark82]

That is an absolutely insane amount of bad hithhikrrs for what looks like 20-30 pounds of live rock…was considering tbs at one point but glad I went a different direction I suppose

 

[jabberwock]

I caught bad hitchers out of my TBS live rock using a clam for bait. Human food clam. Just one in a bottle trap. Actually a tiny mason jar. Had to lean it up on the rocks to allow them to "drop in", and not get back out. The shoulders on this shape of jar worked great.

 

[jabberwock]

I am remembering. The way I caught the first gorilla was to take out all rocks and put them on the upside down lid of a tote for 5 minutes. They tend to "get out" of the rocks for the lack of water. Pick up each rock and give it a shake over the tote lid. see what drops out. Best of luck.

 

[AlaskaMatt]

This is what I’m planning on using:

I thought that maybe experimenting with different colored plastics might help to encourage them to check it out. I have lights out in the tank in about an hour and a half
so I’m going to drop them in about 30 mins beforehand to let them get used to it. Only think im concerned about is that they are pretty short. I’ll be placing them right outside of one of the caves I’ve seen them in and near another area that I usually hear them snapping. If it’s something other than the pistol shrimp I’m hopeful I’ll catch them as well.

I heard about the mason jar trick as well and I’ll keep an eye out for one to use. Right now im using wild caught shrimp for bait — figure I’ll empty the traps out when I wake up. I’ll see if I can’t add that to my arsenal tomorrow.

 

[jabberwock]

FWIW - I observed my TBS rock for 30 days without sand (barebottom). It made catching hitchers a lot easier.

 

[AlaskaMatt]

Are you sure they are pistols and not mantis shrimp or Medusa worms? How did all of those hitchhikers get there? I’m assuming it’s live rock from the ocean? If so, there is a very strong chance of having bad critters that can kill sleeping/newly introduced fish especially those like fire fish that sleep deep in the rocks. Good luck with the extermination!

no I’m not 100%. It’s lots of snapping sounds and I’ve seen two (one of which I’ve caught and donated to the LFS) so I’m assuming that’s the case but it very well might be something else. This is live rock straight from the ocean — it has had a TON of life although to be honest I’m a bit surprised about all the negative hitchhikers — I’ve also had cirolanid isopods as well from this batch but I caught pretty much all of them already I’m pretty sure.

 

[AlaskaMatt]

FWIW - I observed my TBS rock for 30 days without sand (barebottom). It made catching hitchers a lot easier.

That’s a great idea! If I decide to go this route again in the future I am 100% going to give that a go.

 

[AlaskaMatt]

Update:

last night I placed my traps where the shrimps are usually at. I was up at around 2am and I sneaked up to the tank to find a pistol shrimp hiding under one of the traps but not inside of it. Besides my 3 nassarius snails I didn’t manage to catch anything. I will try again this evening.

 

[FishDaddy1992]

I have a fairly large tiger pistol shrimp in my tank and have no issues with him eating my fish. I would suspect something else is going on other than the pistol shrimp attacking your livestock. Mine attacked my serpent star one night but that's because the star tried to get in his cave and hasn't been an issue since.

 

[AlaskaMatt]

I have a fairly large tiger pistol shrimp in my tank and have no issues with him eating my fish. I would suspect something else is going on other than the pistol shrimp attacking your livestock. Mine attacked my serpent star one night but that's because the star tried to get in his cave and hasn't been an issue since.

I’m fairly certain what I have is Alpheus heterochaelis, which prey on small fish in the wild so I don’t think it’s unreasonable to hold these guys accountable. My other guess is it might be my gorilla crabs killing fish in their sleep but I figure the process for eliminating them both is the same.

 

[1epauletteshark]

Make sure to post pictures under white light of whatever you end up finding and good luck. IMO and IME it is probably gorilla crabs although if the type of snapping shrimp that you have are known to eat fish then you are probably right .

 

[ISpeakForTheSeas]

I’m fairly certain what I have is Alpheus heterochaelis, which prey on small fish in the wild

Just pointing this out, Alpehus heterochaelis is actually a known filter feeder, not a predator:

"Along the U.S. mid-Atlantic seaboard, the bigclaw snapping shrimp, Alpheus heterochaelis (Say), is associated with intertidal and shallow subtidal soft-sediment habitats (e.g., oyster reefs and mudflats) and is reported to be restricted to shallow burrows and depressions beneath oyster shells adjacent to salt marsh habitat (Hay and Shore, 1915; Williams, 1965; Nolan and Salmon, 1970; Lippson and Lippson, 1984; Williams, 1984). These shrimp are relatively sedentary, filter feeding from within their shelter from waters drawn into burrows by paddling with modified pleopods (Nolan and Salmon, 1970; Lippson and Lippson, 1984)."*

"Alpheus heterochaelis, another filter feeder, is commonly found among shells (Williams 1984)"**

Symbiosis between an Alpheid Shrimp and a Xanthoid Crab in Salt Marshes of Mid-Atlantic States, U.S.A.

Abstract. Instances of mutualism and commensalism between alpheid shrimp and other marine invertebrates and fish are common in tropical waters. In this stu

academic.oup.com

https://www.researchgate.net/publication/232430934_The_role_of_oysters_in_habitat_use_of_oyster_reefs_by_resident_fishes_and_decapod_crustaceans

 

[AlaskaMatt]

update: found my firefish

As you can see he’s hiding back in the rocks. It’s really hard to tell but his left fin is almost completely missing and he has a red scratch there.
I’m positive whatever did this was the same culprit who caused the disappearance of my blenny who was sleeping in the same hole my firefish was before “the attack”.
i did read the article about the pistol shrimps I thought this one was — at this point I’m not convinced whether it was the pistol shrimp or a gorilla crab, maybe something else? Well the hunt continues tonight.

 

[Anemone_Fanatic]

People often underestimate pistol shrimp. They can cause big problems as adults. The Caribbean species can get very large and do a significant amount of damage. I have half a dozen in my tank, and at least one is around 1.5" - 2", and my emerald crab populations are going down. Fish being wounded sounds a little more like a gorilla crab to me, though. Keep trying to trap them, you should get results eventually.

 

[1epauletteshark]

update: found my firefish

As you can see he’s hiding back in the rocks. It’s really hard to tell but his left fin is almost completely missing and he has a red scratch there.
I’m positive whatever did this was the same culprit who caused the disappearance of my blenny who was sleeping in the same hole my firefish was before “the attack”.
i did read the article about the pistol shrimps I thought this one was — at this point I’m not convinced whether it was the pistol shrimp or a gorilla crab, maybe something else? Well the hunt continues tonight.

Glad at least that guy is still kicking, hope you find the culprit soon