Cleaner Shrimp Deaths: A Whodunnit Poll

What are the most likely possible reasons our Cleaner Shrimp died?

  • attacked by Midas Blenny

    Votes: 0 0.0%
  • attacked by Pink Streaked Wrasse

    Votes: 1 10.0%
  • attacked by Peppermint Shrimp

    Votes: 0 0.0%
  • attacked by CUC member (hermits, worms, etc.)

    Votes: 1 10.0%
  • attacked by Bubble Tip Anemone

    Votes: 1 10.0%
  • attacked by predator hiding in live rock

    Votes: 3 30.0%
  • water parameter issue

    Votes: 3 30.0%
  • toxicity issue

    Votes: 2 20.0%
  • general reefer error

    Votes: 0 0.0%
  • no idea

    Votes: 2 20.0%

  • Total voters
    10

NY_Caveman

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We had two Cleaner Shrimp for six weeks. One was almost 2” the other about 1.25”. They were healthy, eating fine and molting regularly. This week they both died. I have kept Cleaner Shrimp in the past with great success and am a bit at a loss as to their demise. The smaller of the two vanished about five days ago (originally figured he hid to molt). The larger one seemed fine, but two days later, we found his remains. The remains were very near the Bubble Tip Anemone, but I am not certain the anemone was the cause for reasons I will discuss below. Also in that vicinity were Palythoas and where the Peppermint Shrimp makes his home. Last note, all snails in the tank seem fine, but I have noticed that the Peppermint Shrimp seemed to lay low for a couple of days and one of our three hermit crabs has been very sluggish. These could be related to a tank issue or they could have simply been preparing to molt (for example).

Our Tank: JBJ 45 Flat Panel AIO
Filtration: Live Rock, Skimmer, Activated Carbon, Small Refugium
Parameters:
NH3 = 0 ppm
NO3 = 4 ppm
PO4 = 0.24 ppm
pH = 8.0
SG = 35

Since both Cleaner Shrimp died within a few days of each other, I am concerned. It is possible I suppose that the larger Cleaner killed the smaller one and then met his own doom. I listed some possibilities in the poll above and now I will address each one.

Fish Attack: We have a 2” Midas Blenny and a 1” Pink Streaked Wrasse. Neither seem to be a likely candidate for taking down two Cleaner Shrimp. The Wrasse lived in the large cave in our tank with the Shrimp and there was never any aggression. Never any from the Midas Blenny either.

Peppermint Shrimp Attack: We also have a 1” Peppermint Shrimp. His was the smallest of the three Shrimp and always would keep clear of the large Cleaner Shrimp who died. He is feisty and semi-aggressive to smaller critters, but I am not sure he would have killed a Shrimp twice his size.

CUC attack: I do not think a dwarf hermit could pose any threat, but maybe a large bristle worm would be able to right after the Shrimp molted and he was vulnerable? We have a couple 5-6” bristle world for certain. Seems like they are more scavenger than attacker.

Bubble Tip Anemone attack: In general a Bubble Tip Anemone could eat a shrimp. However, our BTA is only about 1.75” in diameter. Additionally, he was added to the tank just this week. It seems unlikely he could kill two shrimp at a time he was recovering from being shipped. I will note though that his addition was one of two major changes made to the tank this week. For that reason it seems possible it is related.

Hidden Live Rock Predator: This is definitely a possibility and always a risk with real live rock. I have not seen anything questionable yet.

Water Parameter issue: Shrimp are very sensitive, especially to metals. A recent ICP-OES test indicated we had elevated Zinc levels of 11.47 μg/l. This level does not appear to be a danger level, but again, Shrimp are sensitive. That said they have lived with that Zinc level for weeks with no issue. All other parameters have been stable. PO4 is trending lower.

Toxicity issue: I do have some Palythoas that came in on my live rock. The anemone was placed pretty close to them. It is definitely possible the anemone or the Palythoas have done something to foul the water.

General Reefer Error: in addition to a regular 10% water change this week. I did a big cleaning on the return and refugium filtration chambers. This was the second major change of the week in addition to the new BTA. I cleaned both pumps and the side baffle walls of both chambers. I then removed the water from that area for the water change. I suppose I could have stirred something up, but the tank has only been running two months.

Would love to hear any thoughts or opinions from other reefers. Thanks!


 
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Brew12

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I'm going with the metals theory. that can cause issues over time. Not sure how much zinc is a problem though.
 

Retro Reefer

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If your peppermint isn’t effected I would doubt water quality issues.. I’m thinking predator in rock or maybe wrasse but the pink streak is supposed to be pretty docile.
 
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NY_Caveman

NY_Caveman

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If your peppermint isn’t effected I would doubt water quality issues.. I’m thinking predator in rock or maybe wrasse but the pink streak is supposed to be pretty docile.

The Peppermint did not come out at feeding yesterday which was odd. He did come out for food this morning and ate.

The Pink Streaked Wrasse is very docile. Even quite timid at first. Seems unlikely, but not impossible. She shared a big cave with the Cleaners for about a month prior to their loss with no issues at all.
 
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KrisReef

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The Peppermint did not come out at feeding yesterday which was odd. He did come out for food this morning and ate.

The Pink Streaked Wrasse is very docile. Even quite timid at first. Seems unlikely, but not impossible. He shared a big cave with the Cleaners for about a month prior to their loss with no issues at all.
Well it sounds like the Peppermint ate too much recently, but that doesn't make him a killer necessarily. Great mystery here, hope you figure out the problem. I'd lean towards a predator attack, but whom (shrimp, wrasse, rock dweller? ) can't really guess.
 
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NY_Caveman

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Well it sounds like the Peppermint ate too much recently, but that doesn't make him a killer necessarily. Great mystery here, hope you figure out the problem. I'd lean towards a predator attack, but whom (shrimp, wrasse, rock dweller? ) can't really guess.

Yes, I am leaning that way myself. I did not make it clear above, but the carcass we found did seem to have been attacked. The CUC, though, could have gotten to the deceased Shrimp before we saw it.

There are a ton of variables, but I am not going to panic or start changing anything. I will monitor for now and hope our fish weather whatever it is.

 
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Caring for your picky eaters: What do you feed your finicky fish?

  • Live foods

    Votes: 11 26.2%
  • Frozen meaty foods

    Votes: 34 81.0%
  • Soft pellets

    Votes: 7 16.7%
  • Masstick (or comparable)

    Votes: 2 4.8%
  • Other

    Votes: 2 4.8%
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