Skunk cories -- new and dying off (long post)

[anonapersona]

Hi, sorry to burst in with a problem, I've lurked here on and off for awhile and rarely post but for a crisis. Unfortunately, I'm back in a crisis again.

I just got some new cories and already 3 of 8 have died. I don't know why. Of the 9 cories I have gotten prior to this bunch, only one has survived. I've tried to not take this personally, but I am beginning to think that I am a poor fishkeper!

Can anyone help me find out what has gone wrong. I have 9 skunk cories in a Q tank, one is old a survivor of my very first tank (one year ago) and 8 are brand new, gotten 2 days ago, 5 in the shipping bag, 3 having been put into the LFS tank for maybe 30 minutes (I asked them not to do that.) Yesterday they all looked fine, ammonia and nitrites both not measurable.

The Q tank is 10 gallon with a whisper 10-20 HOB, filter bag is rather new, no carbon, being on the tank with plants only for a week or more, then the old cory was added for maybe 3 days before the new fish came. I added filter squeezings from the cory's old community tank before moving him and again when adding the new fish. I added Prime to the tank as I added the new fish, in case of an ammonia or nitrite spike.

Substrate is pool filter sand, 1 1/2 inches thick. Water temp is 78F, pH is 7.6 with Co2 injetion and a tiny bit of peat water to soften a bit to GH of 7 instead of 10 of tap water. The tank had been fertilized prior to the fish arriving but not the two Mondays prior to the new fishes arrival.

On the arrival day, I fed them bloodworms, maybe 1/4 cube of frozen, until no one wanated any more. A few were left, 2 or 3 worms, I figured they would get eaten. The next day I fed 1 algae wafer, broken, but no one wanted any, so I tried tiny sinking goldfish pellets, just a few, and removed the wafers that I saw.

One I found this morning, on one side the fish looks slightly bruised. Two others were looking poor, listing to the side and not swimming well. I lowered the water level and let the HOB filter waterfall, in case the Hagen was making more CO2 than they could handle, since the light is not great and the two swordplants in that tank don't make O2 that I can see.

I tested the water, no ammonia or nitrite visible. (didn't test for CO2 before I started aeration). I moved the two poor looking fish to an aerated bucket with freshly dechlorinated tap water but they both died. (pH would have been slightly higher out of the tap and rising with CO2 gassing off)

These fish were gotten Tuesday, two days ago, 5 fresh in the shipping bag. 3 added after just a short time in the LFS tanks -- I asked them to not do that, figuring the breeders water was probably better, even after a 24 hour shipment, than their water with the central filtration. There is no way to know if the 3 that died are the ones that were in the LFS tanks -- they all look alike. The fish were shipped in clear water, not with Methly blue like the other bags I saw there. [edit- these fish were special ordered after I noticed them of the monthly availabilty list, it took 3 weeks for them to come in, so the tank really had been set up a few weeks longer than I said at first]

I've done a large water change, 50%, siphoned off the bottom and found one fungusy looking algae wafer bit that I had missed removing when I saw that no one was eating the others. I moved the Hagen setting to input less CO2. The water level is lowered and the HOB is dropping 1 inch to increase aeration. The two swords will just have to endure.

I do worry that the waterfall and less CO2 is affecting the pH. It was 7.6, same as the shipping bag, before this. Just measured, still 7.6 now. My tap water goes from 7.8 to 8.2 with aeration. I added some distilled water when I refilled to try to keep the pH from bouncing around too much. GH before fish was -- didn't write it down, something like 7, slightly softened from the regular tap of 10 by a bit of peat water extract.

After my great success with the little ember tetras (small, sort of rare, possibly wild caught, now all fine and taking flake food now), I thought maybe I was getting better at this. But, they got the salt dip. Would the cories have lived though a salt dip? Maybe that is the secret to being successful with fish from this store(external parasites?)? if I thought they would survive a dip, I might get 3 replacements from the store. Though I guess I'd have to dump this tank and start over with a fresh tank, clean gravel and so on and dip the fish I have now too. I can do that, if there's a chance it would work and not just kill more fish.

PS -- I just read the post re: c. arcuatus and have to admit that I fed large amounts of bloodworms as the first meal -- figured they were starving, thought that was a good meal, tried not to overfeed but everyone got all they wanted to eat, a few bits left uneaten perhaps. There is an old cory in this tank with the new guys -- I can tell it's him as he had lost all but one barbel. Tank temp is 78 F (25C?) these are skunk cories, C. aeneus (spelling?) if I recall correctly. [edit again- cory arcuatus, like the guy who has them straight from Peru] As of right now, 11:30AM thursday, 3 are swimming around, 3 are sitting, fins not clamped but not fully up either. Those swim if disturbed but seem to not feel well.

It was so cool just yesterday to see all these guys hoovering around.

[STINGRAY]

Hi . You do seem to be having problems. I own a fish shop and would never allow customers to purchase fish before they have been rested properly let alone what you are describing. The poor fish already stressed from transit have been put in an extreme environment for 30 minutes as you say, then caught out and taken to your quarantine tank. I usually bring in corys in qtys over 100 to a bag and we only lose one or two from that batch and these have also been in transit for a day or so. Carry on feeding small amounts frequently, keep the lighting low and do small water changes daily and see how you get on. Best of luck Darren.

[anonapersona]

In the store's defense, I special ordered these fish and when they arrived I was there waiting for the bags to be unpacked. I figured that they could stand another 5 minutes in the bag to go home with me and would benefit from skipping being exposed to the fish store's central filtration system (a large chain store with spotty knowledge from clerks and crowded, mixed tanks). It is an average large pet store, not terrible, not great, run for profit.

When I saw that one had malformed fins, I went back to return it and picked up 2 extras. So, only 3 of the 8 I bought had been "chased around" at all. The four that I got today to replace the dead have had even more trauma, as they were put in a tank with angels, and were kept in a corner by them. I saw an angel nip at one of the cories.

I really thought that I could do better than the store on this, with an actual quarantine tank, frequent water changes. Maybe I have, as they had 4 left of the 10 they started with, though some might have been sold.

There must be something that "good" stores do that I have not done, however.

StingRay, how do you treat cories on arrival? Do you know if they are bred or wild-caught?Ddo you treat them differently if you know?

[Frisckey1]

C Arcuatus is the skunk cory species, also called the Arched Cory.

I had a similar experience with my skunk cories, and it turned out they had a very aggressive bacterial infection when I got them. It was not visible when I picked them out, but it became visible within 2 days of bringing them home. The first sign, as you described, was what appeared to be brusing of the sides and it moved on to the stomach. This was not brusing per say, but the aeromonas bacteria quickly breaking down the internal cell walls of the fish. In essence hemmhoragic septicemia. There was essentially nothing I could do, it moved so very quickly that within days 2 of the 4 died and the 3rd had developed a tiny spot of fin rot. This bacterial fin rot advanced so quickly that this fish's tail rotted off within 48 hours, and then a fungus began to grow. I was able to kill the bacteria and fungus with a topical hydrogen peroxide treatment, but the fish was too stressed and died anyway. Only 1survived. The whole while this was a WELL cycled 20 gallon QT tank and the Maracyn/MaracynII attack I did didn't help either. There just wasn't enough time for the meds to work.

If you suspect this I would IMMEDIATELY return them to the store for a refund or a fresh re-order. Your situation may not be as disasterous as mine, but I just wanted to share my terrible experience so if you started seeing issues, you could act quickly.

Good luck!

[anonapersona]

I saw your posts on that on the board and I don't think this is the same, but I'm watching. The next ones had no bruising, although the one I left in a cup overnight did look bruised by morning where he had normal coloration at the time of death.

After thinking about it a while and looking at the other dead fish, I think the one that had a bruise on the side might have been blood collecting on the bottom as he lay on his side overnight. Maybe I watch too many CSI type shows!

As of yesterday afternoon I added Metronidazole to the tank, this morning I lightly vacuumed the tank and fed some frozen daphnia which was well recieved by all the cories. When they seemed to have gotten most of the daphnia, I added another dose of the Metronidazole. The article on this medication by Josh Kaptur in the Aquasource magazine at TomGriffin.com says to raise the tank temp to 90 degrees, which I have not done. I'm just not sure the cories will be happy with that.

The one that is sitting still with dorsal fin down is pumping his gills, doesn't that sound like a gill problem?


Two of the 8 remaining (7 new plus my old one) are resting with the dorsal fin at half mast. The others are busy around the tank.

[Silurus]

The one that is sitting still with dorsal fin down is pumping his gills, doesn't that sound like a gill problem?

May not be. Sick fish are known to breathe hard.

[anonapersona]

Is it OK to raise the tank temp to 90 degrees F?

[STINGRAY]

No I wouldnt recconmend it, you will only make them worse. We usually only use metrodozinale on Discus, were yes the temps are higher so cant say how it works at lower temps. Do the corys seem any better today. Try and ask your lfs if they can keep fish back for you in future, it will prevent this problem occuring again. Generally corys from S America are wild but many are tank bred now all over the world. We treat all of our fish with the respect they deserve, be they an humble neon or thousand pound catfish, so all get quarantined. As for introducing the fish to your tank everybody as there own methods, but generally fish that have travelled from abroad long distance fair better when they are put straight into conditioned fresh water, so they can clear there gills quickly and get used to there new alien environment.

[anonapersona]

. Do the corys seem any better today.

One dead this morning. Total is now 5 dead of 12 purchased. I've been watching two all day. One seems to get up and get busy occasionally and when resting has the dorsal fin fully up or very nearly so.

The other stayed away from the pack and held the fins at half mast or less. I just removed him to a bowl as I noticed one eye bulging. No sign of swelling in the body or pineconed scales. Could be mechanical damage; when the fish were first added to the tank 2 or 3 got stuck on the whisper uptake as they tried to swim behind it. One got stuck behind the Hagen CO2 diffuesr which was not stuck tight. That's possibly just me being hopeful however. I realize that it could be internal infection.

And then the one that the angelfish bit when I was getting the last survivors from the store is a bit swollen at the scratch. It looked pretty superficial at the time, just took some color off the stripe, but now it has a slight swelling. I could try to catch him and apply some H2O2 or Neosporin (ointment or cream? -- I need to look that up as it does matter) which I've seen recommended for goldfish. I also have Melafix on hand but I don't trust that really.

I'll get enough tank water to keep him comfortable and add an airstone. I've turned the air down as low as I can as he is sort of agitated.

This morning I did a 30% water change (adding a bit of peat tea and a bit of distilled water), siphoned off the gravel surface, fed a bit of frozen daphnia, and treated a second time with the Metronidazole.

Is it possible that though the Q tank was matched to the shipping bags pH, that there might have been a big enough difference in hardness to create a problem? I didn't think to test the bag for GH before I started dripping in tank water to help match the temps. Once temp was equal, a change of 4 degrees, I netted the fish into the Q tank. My tank has GH of 8, slightly softened from tap water of 10.

[STINGRAY]

Not sure what to suggest now on this one. Melafix works well double dosed on sick cats, with the help of oxytetracyclin it recovered a very sick Syno Granulous. Cory cats are usually ok in most water parameters but most of these probs seem stress related . They may have had a poor time in shipping and it as put them over the edge. Good luck with the ones left. Darren.

[clothahump]

Sounds to me like they are being constantly stressed from all the messing about with water parameters and dosing with chemicals, let them settle down and if possible put them in a decent sized aquarium, the larger the body of water the better.
I would do 10% water changes daily with good quality dechlorinated water, do not feed for two days and as I said before let them have a rest from all the messing about.

[anonapersona]

The pop-eyed one was dead by morning, now 7 left, the old cory plus 6 new. Everyone is busy and they run to the back of the tank when I approach. The one with a scratch seems to be healing. None are isolating themselves as of today.

clothahump: 10 gallons is all that I have to offer as a Q tank, other than a large bucket which would make filtration a problem. Daily water change is right around 10%. With todays water change I did not try to soften the added water with distilled or peat, they will need to begin adjusting to the tap conditions.

Do not feed? The earlier suggestion of small light meals seems better. I am feeding very lightly twice a day, two small shrimp pellets total, or 10 grains of tiny pellet food. If I feed frozen food they get just a tiny bit. They are all busy hunting for food, which seems like a good thing.

These fish are destined for a 59 gallon tank, not set up yet. But they have a long quarantine ahead of them first. Ufortunately I still want 9 or more total. I've had my heart set on getting more of these guys to keep the old guy company and I had no idea it could be this difficult. I figured that I could do better than the mega-LFS, and I probably have, but I never expected 50% losses. I just hope that tomorrow turns the corner, it doesn't look like anyone is in trouble now.(crossing my fingers)

[anonapersona]

C Arcuatus is the skunk cory species, also called the Arched Cory.

I had a similar experience with my skunk cories, and it turned out they had a very aggressive bacterial infection when I got them. It was not visible when I picked them out, but it became visible within 2 days of bringing them home. The first sign, as you described, was what appeared to be brusing of the sides and it moved on to the stomach. This was not brusing per say, but the aeromonas bacteria quickly breaking down the internal cell walls of the fish. In essence hemmhoragic septicemia. There was essentially nothing I could do, it moved so very quickly that within days 2 of the 4 died and the 3rd had developed a tiny spot of fin rot. This bacterial fin rot advanced so quickly that this fish's tail rotted off within 48 hours, and then a fungus began to grow. I was able to kill the bacteria and fungus with a topical hydrogen peroxide treatment, but the fish was too stressed and died anyway. Only 1survived. The whole while this was a WELL cycled 20 gallon QT tank and the Maracyn/MaracynII attack I did didn't help either. There just wasn't enough time for the meds to work.

If you suspect this I would IMMEDIATELY return them to the store for a refund or a fresh re-order. Your situation may not be as disasterous as mine, but I just wanted to share my terrible experience so if you started seeing issues, you could act quickly.

Good luck!

I have read of a hydrogen peroxide dip for goldfish treating dacs, gyros and flukes. Is that what you did? A 10 second 10% H2O2 dip has been used on fancy goldfish (the most sensitive dam creatures ever invented) with success. I've read the cory are too sensitive for potassium permanganate, no one answered me as to whether one could do a short salt dip on a cory. It sure seems that these skunk cory need some sort of treatment to clean off some sort of thing that is quite fatal. I've been waiting a year to get these and I've lost half of them already.

[anonapersona]

Friskey1: I'm starting to wonder if thsi is the same problem that you had.

One more cory has begun to lay around too much. He has a spot of something white above his eye. Rather like the one that had the angel bite that got better.

When I look at pictures of this cory I see that mine all have much shorter tails. Are the tails decaying before I noticed?

[anonapersona]

The spot obove the eye is gone on whichever fish that was. Like the angelfish bite on another it has healed.

But this fin decay is real. I've isolated one fish after dippng him in the 10% H2O2 solution for 10 seconds. He survived that, I wasn't sure he would. But the tail fin is nearly gone now. Two more fish in the Q tank have visibly shortened tails. There is no fungus visible, no ragged looking edges, just no fin.

The Metronidazole doesn't touch this, obviously.

Should I try Melafix? Can I do that with the other medication in the water? I am very wary of mixing meds and even of doing too many too fast, but I don't think I have another day with the isolated one, maybe two days with the others in the tank, before they are seriously damaged. I guess I need to try it, I sure don't know what else to do. These fish aren't going to live unless I discover somehing to stop this.

Help!!.

[clothahump]

Melafix does seem to work with tissue regeneration, do a water change before adding it.

[anonapersona]

I got this advice a bit too late, but today is tank cleaning day and I'll do a large water change and redose to account for the 30 to 50% change volume.

Today the remaining fish are all busy and keep dorsal fins up when resting. Two have bobbed tails and I'm watching to see if there is any decay, or if this is just a poorly formed individual.

Now that the ranks have thinned, the fish are more distingushable, and Snub (the old cory with only one barbel), Scratch (bit by the angelfish) and Bob (the bobtail that is not Scratch) have picked up names, tho the other two still look alike to me. One might be Lump, who had a mark above his eye that healed. Now that they are individuals, any future deaths will be that much more disturbing. <sigh>

Meanwhile I have bleached all Q tank implements (nets, buckets and such) and they are drying. I have 4 dead bodies t return for credit to the store. 7 dead of 12 bought, that is just so sad.

Still I wonder what it is that caused such massive deaths (which I hope have ended!) I note that it is winter in Peru, where these fish presumabley were wild caught, since they appear to be full grown. Is there any reason to suspect that there is a bacterial infection that is stirred up by moving from cool water to warm out of season? I intend to get more of these guys (assuming the LFS will cooperate, since they have borne the lions share of these losses with their return policy) but I have to have some procedure in place to pre-treat them as this may be a common problem.

And, can anyone tell me if these cories would have lived through a brief salt dip, say 1 teaspoon per cup which is ~ 5 tablespoons per gallon? a 5 minute dip or maybe 10 minutes?

[Frisckey1]

Anon, even though your situation may not present itself as mine did, I do believe (rather strongly) that you are encountering a bacterial infection. Every single symptom you've listed points to bacterial in nature. Melafix won't help.

My suggestion is to treat with a gram positive/negative antibacterial treatment, like maracyn. Perhaps Kanamyacin, tetracyline or the like.

your fish are stressed. #1) because you added too many fish too quickly to one tank and #2) becasue they came to you with something that's obviously making them feel ill.

I would NOT recommend upping the temps, for 1 reason: IF the bacteria resposible is the same type that causes columanaris, it will respond favorably to a temp increase. It will muliply much more rapidly and kill off your fish more quickly.

I would not LIGHTLY gravel vac, some bacterias actually feed off of the mulm sitting in the gravel. You need to keep this tank PRISTINE until your fish are better. No telling which bacteria you may have, but better to be safe than sorry. Suck that puppy clean! If they are infected with a bacterial infection, they are likely expressing it in their waste production, so I might also be inclined to 1) up the water changes to 20% daily and 2) net any feces laying on the bottom whenever get a chance between changes. This will help lighten the bacterial load in the tank. Ixnay the distilled/ro combo. Starting with your next water change add alot less of it, or none at all. A gallon or two of non distilled water might actually help. Fish need the minerals in the tap or well water, the more of them...the better.

That's my take on it and I encourage you to do some research on internal bacterial infections in fish. Google will get you some good results.

Good luck with whatever route you take!

[Frisckey1]

Oh, and if the fin rot is progressing fast like mine did, the hydrogen peroxide dripped on the rotting area stopped the progression and killed the subsequent fungus that followed right behind.

I do believe your cories would survive a salt dip, briefly. I actually kept mine in a 20 gallon with 1.5 tbspns per 5 gallons of water for several months before I got them a new tank that they didnt' have to share with my mollies. I don't know the recommended process for a dip as opposed to a continous bath, but perhaps just a couple of minutes? Like I said, do some research...the Internet has everything!

[anonapersona]

Beleive me, I've been everywhere looking up info. Most fish health sites are koi and goldfish oriented, due to the cost of either easily getting into the $400 range. I've read on FishVet, PondDoc, Puregold, SkepticalAquarist, plus an assortment of other sites I can't recall. I've been looking both here and readiing at ScotCats. I know that cories are not able to take the treatments that other fish might and so I've been hamstrung, can't use some of the fisrt things I'd use on a goldfish or koi, like Potassium permanganate or salt. I have a basket full of meds from the pond, some old, some new, but all so strong I don't want to use them blindly.

I wasn't clear about the distilled water I suppose, I was adding a pint perhaps, with 3 galllons of tap water during those first few water changes. Just in an attempt to keep the net result from being quite as hard as my tap water. I had softened the water just a tiny bit with peat before the fish arrived and then was stuck when doing a large water change, needing to try to keep parameters stable.

Today was water change day and so this tank got a 50% water change, which is my usual procedure, straight tap water. I will continue doing what I can to keep the gravel clean on a daily basis also. Water quality has been perfect, no ammonia or nitrite, nitrate was well below 5ppm this morning. KH = 7, GH = 9. I reapplied the Melafix to account for the new water and gave the 5th and final treatment of Metrnidazole.

As of right now, all 6 fish are up and busy. No deaths today! yea!

anona, celebrating my first full year of aquarium keeping tomorrow.

[Frisckey1]

There's another one I use, called http://www.fishyfarmacy.com

They have lots of info there, too, as well as sort of a step-by-step diagnostic to try and figure out what's wrong.

Oh, yeah...happy anniversary!

[anonapersona]

All 6 are up and wagging around the tank. Barbels and fins still looking good.

Guess this means the Quarantine clock has begun. 4 weeks with no problems, here we go (I hope!)

PS, thanks for the fishyfarmacy link, I had found that one too. No clear path describing what was going on in the tank, however. Had they begun, fish lethargic, dorsal droopy, then dies....

[STINGRAY]

Glad to see things have improved for the better. Can you get antibiotics in your country of origin as it may be wise to get some in the future, just in case. I can recall buying some Dianemia some years ago which suffered a similar fate, unfortunately not much was known about Flexibacter at the time.If you do reorder try and acquire some smaller specimens. We recently bought in 120 corys via Miami with only 4 losses and this batch included arcuatus at around 2-3cm, looking fine. Good luck .darren.

[anonapersona]

I do still want more. I can get antibiotics at the local stores pretty eaisly, just the standard fish types, cheaper on line, faster at the store.

Is there some seasonality to these fish? Fall, spring?