Ghost shrimp, cherry predators?!?

[7Enigma]

Hello everyone,

I had a bad surprise when I came to work today to check on my invert tank. I have a 10 gallon lightly planted (anubias barteri) invertebrate-only tank that is heated and filtered and been doing great the last month. I purchased 15 cherry shrimp from a local auction and they were doing great in the tank cleaning up the algae and eating the little bit of flake/crushed up algae wafers I fed twice a week. In this tank I also have 3 ghost shrimp that are full-size. The trouble started on Wednesday before I left for the holiday. I did a 25% water change and fed some crushed up algae wafer. I did turn off the filter to let the food settle and forget to turn it back on for 2 hours (I know I know!). I added 5 drops of prime to the outflow of the filter to take care of any minute ammonia that might have been the cause of the deaths. But everything looked fine and I thought I had dodged a bullet.

Before I left for the day I noticed one dead ghost shrimp and 1 dead cherry. I immediately sucked out the ghost shrimp but the cherry was being busily munched on by one of the 2 remaining ghost shrimp. I did not try to separate the ghost shrimp from the dead cherry (he was already half-eaten). I left for the holiday and hoped when I came in today there would be no new casualties.

But when I walked in this morning and looked in the tank (tank lights are on a timer for 10 hours a day) I couldn't find a single cherry. I have looked 3 separate times now and there is NO TRACE that a cherry ever was even in the tank. The 2 ghosts are cruising around the tank doing great. It's like someone at work is playing a dirty trick on me and fished all the cherries out of the tank!?!?!

Now I've read on here and other places that glass/ghost shrimp are not aggressive to dwarf shrimp, but my own experience with these guys is that they are hyper-aggressive to each other when feeding. I had stopped feeding flake food to them 2 weeks ago and switched to the crushed up algae wafer for fear of something being wrong with the flake food (because every time I fed I would count one or two less the next day). But now I'm wondering if this particular strain of ghost shrimp (and I have confirmed they are in fact American ghost shrimp) is a much more violent and territorial beast similar to the macro's?

They tend to stay away from each other and when crossing paths will seem to attack each other slightly before they separate. Feeding time is the worst because they frantically try to get all the food for themselves and there is definite violence with their appendages. I don't know if the living conditions in the tanks (Petsmart is where I purchased these) is causing this or what, but I'm starting to believe my original instinct that it's not just my tank conditions causing the issue.

Now I know the first thing you will say is I'm overfeeding/etc. But here's the deal. I'm feeding a TINY amount of flake/crushed algae wafers only once or twice a week. No food is left to rot in the tank and I've got a large (meant for 20-50 gallon tank) HOB filter with a sponge on the intake to prevent sucking up shrimp and to supply them a place to graze, and this is a 10 gallon tank. My water quality is pristine to the point where my anubias is clearly showing signs of nutrient deficiency (yellowing), but I don't dose fertilizers for fear of harming the shrimp.

I'm in the process of contacting the supplier of the cherry shrimp to hopefully get another batch. If so I'm seriously considering testing out my hypothesis with one of the cherry shrimp to see if the ghosts actively attack the cherry, or whether they are just eating them once they are dead (again the odds of ~10 cherry shrimp dying while the 2 ghost shrimp are fine seem very unlikely to me). I know it sounds cruel/sick, but for my own sanity (and furthering the understanding of the ghost shrimp's behavior) I am giving serious consideration to testing this out. My hope would be for immediate attacking (similar to the way they go after flake food) which would directly confirm my suspicion rather than having to sit and watch them for a couple hours/days as that is not practical at my work.

Thoughts?

justin

[fishbone]

I apologize if I am being dense and missed something in your post, but for clarification, did you purchase both the ghost and cherry shrimp at the same time? If not, my guess is the cherry shrimp did not acclimate right, died off, and the ghost shrimp started munching off them. When I bought my batch of 10 cherries, a month later only 4 survived despite my best efforts.

[Mustafa]

fishbone is right...your red cherries died and the ghost shrimp started munching on them. The ghost shrimp are not capable of preying on live and healthy dwarf shrimp. Their chelae are just not made for that purpose. Sometimes people see a half-dead but still moving shrimp being eaten by ghost shrimp (or even other dwarf shrimp) and think that the shrimp is being "killed" by the other shrimp dining on it...but that's not the case. Appearences can be deceiving.

The fact that you found a dead ghost shrimp and a dead red cherry is a strong indicator that something is/was wrong in your tank.

[7Enigma]

Fishbone,

Ghost shrimp were purchased several weeks before the cherry shrimp. The cherry shrimp were fine in the tank for 2+ weeks. The problem seemed to occur after a water change and light feeding (it was the day before Thanksgiving and I wanted to ensure they had good conditions prior to the long weekend). I did a 25% water change and fed. I had 1 ghost and 1 cherry death before leaving for the weekend.

My concern was the complete loss of all cherry (who again had been doing great in the tank for the previous 2+ weeks), while losing no additional ghost shrimp. Today both ghost are still doing fine in the tank, and so that is what had me questioning the possibility that the ghost were becoming predators to the much smaller cherries. Again I know that is not the typical behavior pattern, but I'm wondering if once the ghost got a taste of the cherry it saw it as food instead of another tankmate.

I understand they will eat their own once dead/wounded, but it just seemed very unlikely that every single one would die while no additional ghosts would...

I am still in the slow process of switching the water supply to 100% my home water so I can take that possibility out of the equation.

[fishbone]

Shrimp won't die right off the bat. Some do, some don't. It entirely depends on how each of them handled the transition. Like Mustafa said, I don't think ghosts are capable of killing even if they wanted to. I have had ghost shrimp live with cherry juvies and still do and have not had a problem.

[7Enigma]

Well I've made another attempt at housing inverts as I picked up a dozen ghost shrimp from Petsmart again. After all the problems I've completely changed the water in my 10-gallon tank (removed all traces of work water and have been carting my water from home, which also should be similar to the water at Petsmart since we are about 4-miles from each other). I also have been running the lights the last 2 weeks even with nothing in the tank (with a very light feeding of flake to keep the bacteria alive) to make sure there is ample food supply for the shrimp. I've also decided to completely avoid feeding unless the tank is barren. I've devised a very gentle way to do water changes by drip acclimation. There is a cupboard over the tank and I can put a container there with some tubing and have it slowly drip into the tank over the course of a couple hours. It takes about 3-4 hours for a gallon of water to be added. This should prevent any issues when doing a water change (but is likely that the problems before were from my work water and not the actual water change).

So of the dozen, 10 survived the acclimation process (did drip acclimation with several dumps of the water to minimize the amount of diseased/medicated Petsmart water). As of today there are 6 I can count at any one time, which means there are probably close to the 10 when I left on Friday. (they're ghosts so tough to see and I have some anubias in the tank that hides them quite well).

My next aquatics meeting is Jan 7th where I hope to pick up another batch of cherry's and hope they do better than the first try where there was a sudden die off.

I'll keep this thread updated from time to time, hopefully with good results.



<side rant>

Petsmart is a horrible place and our local one is one of the worst kept aquarium sections I've ever seen. They should have their license removed from being able to house fish/inverts. The middle-aged lady who worked there (likely "runs" the department) started asking me all of these questions when I was asked for a dozen ghost shrimp. "What size tank?", "What else is in the tank?", "Are you going to feed these to something?". These questions would have been great IF the lady actually knew what she was talking about (highly unlikely but fortunately I knew the proper answers to get her to stop questioning me, that would be 10 gallon, nothing, and no). This also would have been fine if not for the fact that almost every tank had multiple dead things being eaten by half-dead things. I was shocked that the ghost tank (which had about 20 frogs in it) had 3 completely dead frogs (which the ghosts were eating). I would have expected the ghosts to quickly die since the water system was temporarily turned OFF so they could feed all the tanks. Seriously if I could easily (and cheaply) get a better stock and not give this horrible company my money I would do it.

<end rant>

[fishbone]

What worries me a bit is the changing the whole water part. Are you sure the tank is well established?

[7Enigma]

What worries me a bit is the changing the whole water part. Are you sure the tank is well established?

Hi Fishbone,

This tank has been established (and fully cycled) for years. I used to have a dwarf puffer that lived to a nice ripe old age. After that I decided to go invertebrate only (because it's a work tank and I don't like to not feed over the weekend). The problem is the building I work in is old and the water quality is questionable (we don't drink it) and it sometimes has the smell of pipes. I've had a TON of problems trying to care for snails/shrimp over the past couple years and tend to believe it's not the fragility of the species' but rather the water quality. So I've taken that possible variable out of the equation and gone to lugging in water from home (which does great in my 20-gallon tank at home). While a pain, so far (crosses fingers) the shrimp seem to be doing fine, but I won't know for sure until I get some cherry shrimp again and have 20-30 total shrimp in the tank. At that point I can start monitoring conditions and see if the problem(s) is/are fixed.

I've been in the hobby for quite a while, and that's what makes this process so frustrating....

[FeedingFrenzzy]

Have you tried a copper test ,could be lots of trace metals from those pipes. just another thing you can rule out if u test it . good luck

[7Enigma]

Have you tried a copper test ,could be lots of trace metals from those pipes. just another thing you can rule out if u test it . good luck

Nope, haven't done a copper test. I've switched out the water from work to home and my home water is fine. I have no substrate in the tank so I don't know how much copper could leech into the tank (no decorations, just some anubias). I went to work today (been gone since Thursday) and could only see 2 ghost shrimp in the tank (from 10 after the acclimation), have not fed anything, algae well established on the walls of the tank, and have been doing very small (1 gallon) water changes with a drip method. I'm going to try one more batch of cherry shrimp and then if that doesn't work I'm calling it quits with inverts. I've put too much time and effort and gotten rotten results..

[fishbone]

I ... uh ... got nothin'.
I hear ya, it's frustrating to say the least. My experience with shrimp has been similar, at least as far as ghost shrimp are concerned. I don't think they are well taken care of to begin with. I had ghosties lay eggs and hatch in my tank and that seemed to be key to success. Never had much luck with buying them from pet shops. Cherry shrimps, same story. Like I already said, bought 10, only 4 made it, now I have over 30. I think it's time I swam some out to maintain genetic diversity. So far they are doing great, it is a planted tank, I dose with ferts and I have neons. Everybody is happy and I constantly see new babies.

[7Enigma]

Well as I mentioned the Petsmart tank that I got this last batch from was less then ideal (dead frogs in the tank), but shrimp seem to be so fragile that they die off extremely quickly in the presence of toxic conditions. I'm not concerned that much about the ghost death, but I will be if my next cherry batch (which comes from a private local breeder) suffers a similar fate.

[fishbone]

Shrimp are just about the most sensitive as far as I know. When crap went wrong in my tank, the death order was shrimp first, snails second, fish last.

[7Enigma]

Well it's been awhile, but finally I got another batch of cherries from a local breeder. I got a dozen, did the slow acclimation period and since the addition on Friday have only physically seen one dead (could have been 1 of the 2 ghosts as it was just a small piece of a shrimp left).

Since my last post I have continued to do water changes using only water from my house (trudged into work 1 gallon at a time), and that has definitely helped somewhat.

The cherries are very active and some are a very dark blood red (which is good I assume). There have been constant molts when I come into work each day. I can count 8 as of this writing (and they are tough to spot so I'm hoping there are at least a couple more).

My question is exactly how small are the cherries when young and what color are they? I normally do vacuum's of the bottom of the tank (I have a bare-bottom so cleanup is super easy). Due to my HOB filter outflow I get a nice clump or two of settled debris but don't want to risk sucking up some babies. Can I safely just leave the detritus on the bottom of the tank and suck water from near the surface? I do 20-40% water changes per week.

Thanks,

[yuanyelss]

It entirely depends on how each of them handled the transition. Like Mustafa said, I don't think ghosts are capable of killing even if they wanted to....