why are shrimps dying?

[urban reefer]

Please help! I have been having a bad few weeks in the tank -- much death and sadness and I'm starting to feel unworthy of reefkeeping :(. Sorry for the long post, but I want to include as much info for diagnosis as possible. Tank parameters and tankmate listing are at the bottom.

Over the last six weeks or so I have lost 6 shrimps -- peppermints and skunk cleaners -- and a flame angel. I suspect the flame angel succumbed to gill flukes. I didn't see any lesions. but the fish just slowed down and flapped his gills heavy for a day or two and then died. I tried a freshwater dip but too late.

That makes me think maybe the tank was not coppered (otherwise how could the parasite live?), so I'm not sure why the shrimps have been dying. I only witnessed one of the deaths. The shrimp spent several days, maybe a week being somewhat listless under a ledge and then showed up in out the open today looking like it was filled with white stuffing.

Possible reasons for my problems:
- aggression by other tankmates (see list below): My observations have been that everyone gets along and if anyone was a bully, it was the shrimps against the snails and crabs. My clownfish are afraid of their own shadow. The shrimps are really peps and skunks, NOT coral-banded, etc.
- nitrates -- while I have had trouble measuring them accurately, they may be high (see below), but the corals all seem to be in good health
- salinity -- I have kept it a bit high, I suppose this is the most plausible story, but I thught stability was more important than level?
- parasites: do they attack shrimps? why haven't the clownfish had any problems?
- other????


Anybody have advice on what I can do to stop this horror??


Tank setup and conditions:
38 gallons with about 30lbs. LR, 5" DSB, and skimmer
setup about 6 months
Water params:
ammonia or nitrite are zero
nitrate = 5-10 ppm using Fastest, 25 using Salifert
salinity = 38 (steady)
temp = 81.5 (steady)

Not much has changed except:
- started dosing ESV B-ionic
- have some red stuff (cyano?) on the sand and some diatoms, not heavy

Other inhabitants
- pair of false percs
- hammer coral, colt coral, frogspawn
- assortment of blue and red leg hermits
- assortment of snails

Feeding: two tiny feedings a day of flakes in the afternoon and a fraction of a cube of variety pack frozen food, occasional live baby brine shrimp

[Blodlizrd]

I don't know too much but I will comment on what I do know.
1) Nitrates aren't nearly as toxic as their bigger brothers Nitrite and Ammonia, and I have kept my fish and shrimp in a tank with much higher Nitrates than what either of your tests are reporting. I'm talking like 75-100 ppm of Nitrate (I know, I didn't know what I was doing... That was before I learned all this stuff that the people here taught me! :P ) So I don't think the Trates are causing the problem.
2) Salinity is a bit high... I run my salinity higher than most because I heard the salinity in the ocean is higher than what most keep their tanks at. I run at 31-33 ppt salinity. That is somewhere between 1.023 and 1.025 Specific Gravity. Still I don't think this would cause the death that you are speaking of.
3) Your not alone with the angel. I have a friend (please forgive him guys) that has accidently killed 3 Flame Angels... He has troubles with them so I am holding off on the angel purchase until I get a little more experience under my belt.

I'm thinking maybe a disease or parasite got to them. Perhaps a silent killer among the rocks that you don't even know is there. I'm sure someone with more knowledge than me will chime in on this one. Hope the info I gave helps though. :D

P.S.: Just to be safe, I would bring the temp down to 77-80 degrees. That is what most people run I believe.

[Pineapple House]

Your salinity is quite high, at 1.029. I would definitaly lower it to about 1.024. I don't think this is the cause to the death, but it would help.

Shrimps will need relitively high amounts of Iodine to live their best. I think their whole exoskeleton is made up of Iodine and Calcium. It would help to know what your Iodine level is at.

This could be a scilent killer? Your tank seems fine, everything seems in check, have you noticed any hitchikers lately?

PH =)

[fishfreek]

Your salinity is quite high, at 1.029. I would definitaly lower it to about 1.024. I don't think this is the cause to the death, but it would help.

Shrimps will need relitively high amounts of Iodine to live their best. I think their whole exoskeleton is made up of Iodine and Calcium. It would help to know what your Iodine level is at.

This could be a scilent killer? Your tank seems fine, everything seems in check, have you noticed any hitchikers lately?

PH =)

Pineapple is correct about the iodine being needed. I am not sure exactly what the best level is but I have heard you should try to maintain it at .06 or was it .006 ? I forget. I have heard from people different stories about Iodine and shrimp. Some say it helps them molt. Others say its toxic to some degree and they molt to rid their body of excess.

Either way it seems to make them molt. Most of the shrimp deaths that I have heard about occur during or just after a molt. THis is when the shrimp is most vunerable. Having the proper iodine level will allow the new excoskeliton to form and harden correctly.

The issue is made even more complex when you talk about the differences between iodine and iodide. Or atleast I think that is the correct term.

At any rate if you add iodine to the tank you should get an iodine test kit and make sure your levels are not to high.

[urban reefer]

I am still wondering whether it might be a parasite. Any thoughts?

[fishfreek]

I have not heard of shrimps being suceptible to parasites. Or atleast the same parasites that fish have.

[Pineapple House]

I agree with fishfreek, i've never heard of a parasite that will go for shrimp. I have a feeling it has to do with the iodine level, have you ever tested for this?

PH =)

[urban reefer]

No, I never tested for iodine. Do I have to have a certain level dissolved in the water for the shrimp to remain healthy??? Never heard of that. I know that iodine (or iodide?) is used in building an exoskeleton, but didn't know how much is dervied from the water.

[HoopsGuru]

A lack of iodine sure wouldn't cause 6 shrimp to mysteriously die over the past 6 weeks. But by being advised to add iodine without knowing much about it you are being led right into overdosing and wiping out your corals. It is very hard to test for as it leaves a system quickly and therefore I think it would be a terrible idea for you since you don't appear to be very experienced yet (don't worry, you care so it will come! :wink: )If you have done any water changes recently, you have most likely easily kept your iodine at an acceptable level, and I would continue to just tell you to do water changes.....MUCH EASIER! As you get more accustomed to proper tank procedures, you could then dive into supplementing.

There are several keys here that I find very important.

First, you mention "That makes me think maybe the tank was not coppered". Did you not start this tank? Are you unsure as to what has been done to the tank in the past? The copper itself is irrelevant, if there was any in the tank your corals and inverts would all be dead already.

Second, you state your salinity as 38 which is already alarmingly high. However, you fail to mention whether or not this reading is consistent. For example, if it is normally lower and recently spiked to 38, this alone could have killed a wide variety of livestock due to salinity shock and shrimp are very vulnerable to this.

Third, it is important to remember that at higher salinity, sw holds less oxygen. This could easily explain the flapping gills of the flame angel.

Fourth, you had 6 shrimp in a 38 gallon tank. IMO, this is way too many and several could have literally been killed by the others, tough to determine since you only saw 1 die and couldn't determine why. I have never seen more than a pair recommended in tank reaching even 75g and would say that this could have very well been another factor......one of several red flags I have seen.

Before you go adding anything, (not that iodine isn't important for shrimp health, but it doesn't outright kill them in a healthy system in a few weeks. I have had mine for 7 months and NEVER supplement iodine.) I would perform a major evaluation of your system. Perhaps you can do it here by supplying all the info of your tank: Tank size, filtration, temperature, salinity, all livestock, maintenance, etc.

In the meantime, attempt to lower your salinity to about 31-32, not dropping more that ½ unit per day to be safe. You can do this easily by siphoning out a small amount of tank water and replacing it with fresh topoff water.

[killroysrevenge]

What is your PH?

[BigFish]

lol this happened to me I only lost two shrimp and am not sure if it is your prob but I bought about 15 pounds of live rock and put it in my tank how I wanted it, Everything was great it looked good ..... but in about three days My shrimp died I wrote it off as just plain death not a big deal my tank had good water quality and all. So I went and bought another shrimp well a few days later he died I was getting pissed then one night I decided to watch my tank after I turned the lights off, About an hour passed and I was about to go to bed when all of the sudden a wonderfully ugly crab appeared he was rather small(not really small but just big enough to eat a shrimp and still be able to hide in the holes), I got rid of him sorry if this sounds mean but my dish disposal worked nicely :twisted: just kidding :D anyway I havent lost any fish since then :lol: . Damn natural live rock. Anyway good luck with your problem

[phistio]

whoa...there are some mixed conceptions...

hoopsguru brought up some excellent points...

iodine can be very detrimental to a reef! it is chemically known as iodide in our tanks, and can be poisonous. lugol's is a tincture of iodine that becomes iodide or more correctly sodium iodide an additive of table salt. shrimp do not have to have supplemental iodine added to survive. most of the iodine that they get is from natural food, as well, it's found as trace amounts in synthetic sea salt. also, many trace additives contain iodine. IMO there's no need to add iodine to a reef, unless something is dependent on it (such as soft corals like xenia). iodine is something that builds up enough in the shrimp, that they molt...and it's my reasoning that they do this to excrement the iodine out of their system. their exoskeletal structure is comprised of a calcerous shell...

also...many others pointed out that at 38ppt, your salinity is way too high. that translate to a specific gravity of 1.0285. as said the water being that "heavy" almost eliminates the chance of having healthy levels of dissolved O2.

also, your nitrates could also be a factor in the deline of your fish.

[Samurai]

I was about to go to bed when all of the sudden a wonderfully ugly crab appeared

LOL. Wonderfully ugly. Hahahahaha :lol:. I don't agree with the statement that two shrimps is the max for a 75 gallon tank. I think it all depends on the type of shrimp and the number of places for them to hide as well as the bioload that other fish are putting on the system. If they were six coral banded shrimp then that would be too many, but if it was three blood red fire shrimps, a couple of cleaner shrimps and a peppermint shrimp then as long as you kept up with the maintenance and didn't have them in there with a school of chromises then I think it would be fine. Certain chemicals would be used up faster by them, but like I said- as long as you kept up the maintenance and as long as you didn't have a huge number of them then there shouldn't be a problem with keeping more than two shrimps in a 38 gallon tank.

[killroysrevenge]

I have a Cleaner and a Peppermint in a 29gal. tank and have noticed no ill effects. Other than the Peppermint allways hides.