Getting rid of copepods (parasites to sea squirt)

[km2393]

Hi all,
I know that copepods are a sign of a healthy tank, but I run a marine facility in a lab with nothing but Ciona intestinalis (a sea squirt). The copepods get into the siphons of these guys and kill them when they are still juveniles, and my copepod population has gotten so out of hand that none of my juveniles can survive.

I need to get rid of them. I've tried bleaching the whole system, followed by several freshwater washes, then recycling the tank and letting it sit for a few weeks. There would be no copepods for a few days and then the juvenile copepods would pop up, even with brand new animals that were not in a tank with copepods.

I am thinking about getting a natural predator, such as the dwarf seahorse (my tanks are only 5g) but I don't know if they will eat benthic copepods? The seahorses seem like they just float, would they actually go out of their way to eat the copepods off the dishes with my animals on them?

Also, once the copepod population declines, I need to culture shrimp for the seahorses. I think it's safe to say my squirts aren't going to like the shrimp either, so would it be ok to frequently switch the tank that the seahorses are in, given the parameters are the same?

If anyone has another way to get rid of copepods, or another predator that would do well in such a small tank, please let me know. I am attaching a picture of the tank set up as well as the animals I work with.

Thanks!

[ska d]

A Mandarin fish would take care of your pods. They are small but eat non stop. If you have this problem and it is recurring then the Mandarin is your best bet. As long as there will always be pods for the little fella to eat, because that is virtually all they eat. Some have got them onto frozen mysis and such but I'd bet those animals starved after a period of time. I know mine did.

[MondoBongo]

would mechanical filtration through a small diameter screen be an option?

i don't know that any predator will be appropriate for the size of the tank, and effective enough to wipe out the population.

i've seen some differing information in regards to UV sterilization and its effects on copepod mortality, but it may also be worth a try, in addition to other control methods?


A Mandarin fish would take care of your pods. They are small but eat non stop. If you have this problem and it is recurring then the Mandarin is your best bet. As long as there will always be pods for the little fella to eat, because that is virtually all they eat. Some have got them onto frozen mysis and such but I'd bet those animals starved after a period of time. I know mine did.

the tanks are unacceptably small for any kind of dragonet.

[countryboy12484]

Six line wrass maybe?

[gone fishin]

I agree with Mondo. Hopefully Billsreef will see this or try to PM him. He operates labs as well. He may have some insight for you. Good luck.

[ReefkeeperJames]

Run an area of your lab specifically designed to house pods. They will prefer that chamber and be easier to manage elsewhere.

[km2393]

Run an area of your lab specifically designed to house pods. They will prefer that chamber and be easier to manage elsewhere.

This is interesting. What would you suggest? As you can see, the tanks are connected into the same system but are indeed separate. Do you think if I made a copepod friendly tank they would hang out there instead of bothering my squirts? That kind of sounds like it would make the problem worse, like I would be giving them a feeding and breeding ground, but I don't know much so I'd definitely like to hear more.

[km2393]

Ok, I'm the one trying to get rid of the dang pods in my tunicate only lab tanks.

I'm nervous about using a predator, though I will use one as a last resort, but someone mentioned setting up a copepod happy section and they would all just go there.

Do you think that would work? To me, it sounds like I will be giving them a feeding and breeding ground for them to proliferate and increase their numbers even more, but what do you guys think?

And how would I go about doing that? I'll attach a picture of the system, it's eight tanks in series but they are eight separate tanks, so should I just make the last tank a copepod only tank, would they really go exclusively to that tank? I don't buy it.

Of course, if they did, I could always suction them out to prevent the population from going nuts.

Anyway, would it work?

[ichthyogeek]

Setting up a copepod happy section seems like a bad idea to me...you have the perfect habitat for them, and if they get food, that means plenty of babies, and therefore more copepods than the copepod happy section. All organisms produce more offspring than the environment can sustain...which means they either move or die. In your case, you're just getting more copepods.

As for sucking them out, it seems to me that you'd be creating selecting for copepods that aren't visible, and therefore more likely to reproduce. So that doesn't seem right either....

Sorry about that, I just finished an AP Biology course in high school, so all the technical terms are still swimming around in my head.

I'd go with the predator, but seeing as I have no idea what a tunicate is, nor what would eat one, I can't really help you there. Maybe one of the possum wrasses? Or an ultra fine filter that prevented copepods from going anywhere once caught, changed out once a week or so?

[ReefsandGeeks]

i've dipped some of my rocks in hyrdogen peroxide, and when I did, I saw quite a few copodes jumping around and dieing. I've read others use this as a dip that doesn't harm coral, but will kill off algea and other inverts. I don't know how this would effect your squirts, but if they're able to survive, you could do a dip with them, and use it to clean out your system to eradicate them. I don't know the kill rate, if it's 100%, but they did seem to be quickly effected when I did it. The peroxide will break down into H2O and free oxygen, so there will be no residue left over after the reaction. May be worth looking into. I suspect there may be baby copods on the squirts, so if you just remove them and put them back, you may still have them.

[Kyle461]

Or an ultra fine filter that prevented copepods from going anywhere once caught, changed out once a week or so?

This seems like a viable solution. Trap them before they can enter your tanks. As far as the ones there, you might look into different types of dips? I'm not sure how fragile tunicates are but maybe a hyposalinity dip may work to kill off the pods but not the tunicates.

[Sk8r]

Filter sock on the outflow.

[IDreamOReefin]

+1 filter sock. And
If you take a sponge or some other "happy place" and place it in the tank for a short time, like hours, or a day. It might draw them to it and then you can remove it to dry or trash. You would have to be sure to remove it or it would become a breeding spot. But perhaps it would work as way to export them out. If you were to "trap" within all your tanks on the same day and if you remove the "traps" everyday... IDK might be worth a shot. Of course they will still be in and around the frag plugs or rock the the specimens are on. So also research the dip idea. But I don't know about dipping tunicates. GL.

[billsreef]

I hope there are no objections, I merged both threads in order to reduce confusion (at least for me :D ) from having two threads on the subject.

[billsreef]

Hi Kristyn,

Your instincts about the "copepod happy place", and the young ichtyogeek's thoughts, are right on track. It would be the same as running a refugium on a reef tank, a nice place for the pods to reproduce and grow. Simply making more. Quite the opposite of what you need to do.

With your system, how is seawater supplied to the tanks? Natural SW or artificial? Any type of filtration on that set up? Detailed pictures of the whole set up, all plumbing, pumps. filters (if any), etc. would be helpful.

The mentioned filter socks are definitely an option, and a quite good one. Trick is sizing them to allow the phyto to pass through, and still trap copepod nauplii. Then it comes to a matter of placement and routing maintenance. However, the pods need to be cleared out in the first place, as the ones already in the tanks will simple reproduce in the tanks.

[ichthyogeek]

Well this makes sense now, I was reading it and thought "when did I subscribe to this thread?" Okay then...

What might be your problem, is the inline system of yours. Have you tried sanitizing the entire system, pipes, tanks, and all? What might be happening, is that the copepods are breeding in the pipes, and since you don't sterilize the pipes in the process of bleaching, there are still adult populations hiding and reproducing there.

I think you would be best off sterilizing the entire system with bleach, repeating all the sterilization procedures that you've already done. However, I'd also take out the tunicate cultures, and if you can, place them in a large-ish tank, say 10 or 20 gallons, and add a mandarin dragonet, sixline wrasse, or possum wrasse to eat all the existing populations of pods on the cultures. I'd also run a filter sock on the system to catch any nauplii in the tank. If you can identify the pod species via microscope, you can probably find the size of the nauplii on the net, especially if it's a common species. Then it's just a matter of finding a filter sock with a micron rating larger than the phytoplankton species you are feeding, but smaller than the nauplius size of the copepods. So in review:
1)Take out all tunicate cultures, and introduce a known "podivore" to all the cultures to eliminate adult pods. ID the pod species, and use an appropriate filter sock to get rid of any nauplii
2)Sterilize the entire system, pipes,tanks, and all, to get rid of any reproducing populations in hidden areas.

Totally out of the scope of your question, but are you doing genetic research on the squirts? The only thing I got out of the wikipedia article on them was that they were invasive, and used in genetic research.

[km2393]

Thanks everyone!

I've tried adding filters to the outflow, but it starts backing up rather quickly and doesn't allow for proper water flow, which ends up doing more harm than good. Each tank has it's own spout, which is only about 3/4 of an inch wide, so it's hard to add anything that won't mess with the flow.

When I bleach, I leave the systems to run and function as they normally do, so absolutely everything is sterilized. I tried taking the whole thing apart to wash ad bleach everything individually once, but it was more trouble than it was worth and the pods were back as soon as I put salt water back in.

The outflow is well filtered, and there are always adult pods in there, how big are their eggs? The mesh I use on the outflow in combination with two filter socks and a filter pad make it impossible for an unmonitored squirt population to grow anywhere in the system, but it obviously isn't as effective against the copepods. The mesh is 100 microns.

Artificial seawater is used. The tanks are completely cleaned three times a week and it seems like all of the pods are removed during cleanings. I could make sure of it by using bleach and fresh water rinses, but it doesn't seem to be a problem right after cleanings. That's the horrifying part though! These populations boom within 12-24 hours.

Yes, the ciona are being used in a genetics lab. I'm going to take more detailed pictures of the set up and post them, and send them to Bill.

[km2393]

Here are more detailed pictures of the setup.

The whole system is eight tanks, though the top row and bottom row each have their own pump. The water is pumped from the bottom filter section to the tanks, which each have their own valve. The output system is connected for all eight tanks. The water goes through the 100 micron mesh, then through two filter socks, followed by a filter pad and bioballs, then finally through a skimmer chamber, through some rocks, and back to the tanks.

[Kyle461]

There may be a pod population post filter socks in the bioball chamber and the rocks after the skimmer. This population could be reproducing in the sump which would reintroduce them to the tanks over and over again.

[Kyle461]

Thought this journal may interest you:

http://plankt.oxfordjournals.org/content/32/3/305.full

[JamesHolt]

Look into getting a bag filter/canister setup for the output side of the sump system, run your filter socks in it, they are not cheap but effective..
Or you could move the filter socks to above the individual tanks,so it filters the water just before it goes back into the DT..

[laga77]

Running a diatom filter will take everything out of the water. I t can be moved form tank to tank.

[km2393]

For now, I'm going to try different variations on filtering the incoming water. At least, even if I have a crazy pod population, they won't be able to bother my Ciona. I have a diatom filter that I'm saving in case of a serious emergency, but then the algae they eat would obviously be removed from the water as well, so it's not a long term solution, just a control when it gets too out of hand.

Thanks everyone!

[ichthyogeek]

Okay! By the way the least killifish won't work because those are freshwater. I saw your other post on TPT, so I figured I'd nip that in the bud.

The problem with holding the small copepod eating fish, is that most of them are super shy, or need groups. So aside from the dragonets, the majority of the smaller fish you can keep (possum wrasses, trimma gobies, eviota gobies, barnacle blennies, court jester gobies, etc.) will wither in those sterile tanks.

Or, you could try feeding different phyto for a while. From what I understand, Nannochloropsis is a good choice for rotifers, but not a good choice for copepods because the nanno is too small for copepods (it's in the foods sticky in the breeding subforum-the last few pages)

[km2393]

Or, you could try feeding different phyto for a while. From what I understand, Nannochloropsis is a good choice for rotifers, but not a good choice for copepods because the nanno is too small for copepods (it's in the foods sticky in the breeding subforum-the last few pages)

The squirts grow the best on a diet of diatoms and flagellates. (If I'm understanding correctly, Nannochloropsis is neither?) But either way, they won't grow well without a mixture so I wouldn't be able to feed them solely that. I think I can't avoid the copepods liking the food because they're natural competition for my Ciona. I'll look into different algae options that maybe don't support copepods so well though, but that still work with my squirts. Thanks!

[billsreef]

The squirts grow the best on a diet of diatoms and flagellates. (If I'm understanding correctly, Nannochloropsis is neither?) But either way, they won't grow well without a mixture so I wouldn't be able to feed them solely that. I think I can't avoid the copepods liking the food because they're natural competition for my Ciona. I'll look into different algae options that maybe don't support copepods so well though, but that still work with my squirts. Thanks!

Nannochloropsis is a rather small green algae. Aside from the small size, it's typically nutritionally inferior to what you are currently feeding your Ciona. Unfortunately anything that will grow the Ciona adequately will also feed copepods quite nicely. The catch 22 in culture work when have a contaminating critter that feeds on the same foods as the one your growing.

[km2393]

Update: I used the revive and it's way too harsh on the squirts, a lot of them died. I'm going to run the experiment again with a much shorter bath time, but I don't think that's a solution.

Right now though, since the revive did work on the copepods, there are very very few in the tanks. I know that the population is going to explode again because it always does, and right now I have a diatom filter hooked up to hopefully prevent that.

I was wondering what predators could be kept, at least part time, like 8 hours a day, in a five gallon tank.

Also, has anyone used a chaeto ball? I'm afraid this is going to act like a breeding ground like the copepod happy place would, but if there's going to be a ton anyway, do you think they would hang out on the ball as opposed to the squirt dishes? I don't mind if there are a million in each tank as long as they stay away from the baby squirts. Right now, since the dishes are really the only substrate, and the surface is covered in algae, that's where all the copepods tend to congregate.

Thanks again for all your help and suggestions.

[km2393]

Guppies?? I don't know what I would do with them when they grew up though. :/

[CuzzA]

Interceptor would take out the pod population, however, I don't know how it would affect the squirts. I imagine they would be fine since it's relatively reef safe. I also wonder how Bayer insect killer would effect the squirts. Since your running a lab, do some experiments with one outside the main system and see what happens. Also, I would certainly consider adding a six line wrasse.

[billsreef]

Too bad the squirts turn out to be sensitive to the revive. The Chaeto ball will just work out has a refuge for the pods, won't prevent them from being in the tanks with the squirts. As for predators, dragonets, halichoeres wrasses are good choices. Small cunners, that can be caught locally, would also pick off the pods.

[km2393]

I'm wary to try the bayer, but might when I have some larger animals. I'm also a little wary about introducing a predator because the time when the squirts are most sensitive to the copepods is when they're only about 5mm long or smaller. About the same size as the pods, so I don't want to trust a fish not to eat my precious mutants by mistake. Right now it is under control, thanks to the revive, even though it killed the animals. The new ones are able to thrive in pod free tanks thanks to their sacrifice! Thanks for your help everyone.