Sick Corydoras elegans - strange bubble... pics included

[bettanbetta]

Hi,

I recently acquired a small (c. 1") female Corydoras elegans by accident (delivered to LFS in a shipment of Otocinclus affinis). All has been well for the last few weeks, but then yesterday morning I noticed she was looking a little swollen around the tummy. Thinking it could possibly be constipation I added a dose of King British Revitalising Tonic to the tank at around 11pm last night. This morning she had developed a strange clear bubble around her anal area (don't think it is protruding from the anus - looks to be to one side) and a reddening under the skin on the stomach... she still pops to the surface for air, and still moves around, albeit awkwardly. Her fins are clamped and she isn't foraging, just sitting in the current from one of the filters. Any idea of what this could be and possible courses of treatment??

Water parameters are as follows - Temp 27oC, pH 7.2 NH3/NO2 both 0, NO3 10. I change 20% of water twice a week with vacuuming - one change was done the day before this started. Tank is a 34l (18"x10"x12") planted tank with a sand substrate and bogwood. It is heated, filtered by 2 internal filters and lit by 2 x 14W fluo tubes. There are 4 young 1-1.5" female bettas in there and 6 other Corydoras (2 x 1.5" C. aeneus, 3 x 1" C. panda, 1 x 1.5" C. sterbai). The tank has been running with these inhabitants for around a month, and was cycled prior to that.

[catfish_cz]

I don't know what is it.

similar things on catfish

Megalechis thoracata:
http://www.akvarista.cz/web/galerie/ind ... ew&id=1549

Ancistrus sp.:
http://www.akva.sk/phpBB2/showpage.php? ... cbfc6ac0fe

[Mike_Noren]

I've only seen 'bubble disease' reported from Corydoras, although it looks like that Ancistrus has the same disease (to me it looks as if that Megalechis has tumors, as the bubbles seem "meaty").

Basically I don't know what that is, what causes it, or how to cure it. And I doubt anyone does.

As none of the cory pro's, who've, unlike me, probably seen this disease in the flesh, have stepped forward on this, I'll give it a shot...

If it was my fish that was affected, I'd immediately isolate it in a hospital tank, raise the salinity to about 2 grams per liter (Corydoras sensitivity to salt is greatly exaggerated), and also dose antibiotics. If the bubbles didn't recede within a few weeks, I'd destroy the fish (and sterilize the hospital tank with bleach).

Incidentally, someone is bound to tell you that it's gas bubble disease, a disease wherein air bubbles form under the skin of fish kept in oxygen-supersaturated water. I have seen gas bubble disease, and whatever it is your fish has, it looks nothing like the gas bubble disease I've seen.

Whatever you do, please report the outcome here. I don't think this disease is terribly rare among catfish, but very little is reported about what treatments work and which don't. Quite possibly because it is often confused with gas bubble disease.

[pleco_breeder]

As Mike said, I would agree that it is not gas bubble disease since that bubble seems to be opaque in color. However, I would like to add my 2 cents on the treatment option. I agree with most of it, but before destroying the fish I would like to suggest that you attempt to lance the bubble. If you do this, please use a separate container than the tank the fish will recuperate in as a precaution that there could possibly be pathogens inside, and immediately swab the area with betadine. I use this on deep injuries in my pleco tanks, and it is completely safe if swabbed and tends to get bacterial infections from wounds under conrol rather quickly. After swabbing, I would place the fish in isolation for a few days, if not weeks, to monitor its condition before trusting it in a community tank. I have to admit that this is mostly from an experimental viewpoint, but as stated above this is a semi-common occurence. The information gained for the community as a whole could be invaluable and save the fishes life.

Larry Vires

[Coryman]

I have seen this on Corys before and when researching a little deeper into the fishes husbandry I found that in most cases they were being fed on a protein rich diet, which is not good. When the diet was changed to one which contained less protein and a proportion of live and or frozen foods the jelly lumps gradually faded away.

Ian

[bettanbetta]

Thanks for your replies guys... Have already got her moved to a hospital tank this morning. I added King British Revitaliser Tonic to the water as this is my usual method of salting tanks. Would regular salt be better?? The hospital is a 12l acrylic with no substrate, a 25W heater (temp set at 28degreesC) and a mature sponge filter. I haven't fed her since last night, and normally only feed Hikari Sinking Wafers to my Corys with the occasional treat of frozen bloodworm or beefheart that I give to my bettas from time to time. Would the diet issue account for the abdominal/ventral swelling with the reddening under the skin on the stomach?

[MatsP]

I belong to the growing group of people who believe that beefheart is NOT a good food for fish. Nearly no fish will ever get anything similar to that in nature, as most fish don't eat mammals at all.

Fish, crustaceans and insects are the staple diets of many fish, but I'm aware of NO fish that gets any notable portion of it's food from mammals, except for sharks that are knwot to hunt sea-mammals such as seals.

--
Mats

[bettanbetta]

Just a quick update for you. She was transferred to hospital tank yesterday morning and treated with salts (in the form of KB Tonic) and a dose of Interpet No 9 (Anti Internal Bacteria) and this morning the bubble has all but gone and she is scutting around a bit more. Have added a single food pellet to tank so will see if she's now feeding again and will keep you updated on her progress. Thanks again for all your help!!

Mats - I am well aware that most fish wouldn't normally eat beefheart, but it has been heavily used by betta breeders for years to no ill effect and carries none of the risk of pathogens associated with aquatic (particularly freshwater) "meaty" foods... It contains all the nutrients required for growth and so is an excellent fry food - and gives much better growth results in betta fry than any of the standard microworm/grindalworm/bbs fare, as most of these foods are lacking in one aspect or another. It also is not known to cause constipation. My corys pick up the minimal amount that gets past my bettas, and enjoy it. Notably, however, many land mammals are fed fish meal as food, including agricultural beasts and birds, and I'm pretty sure that most mammals don't eat fish in nature. I don't think its fair to condemn an effective food for where it comes from... Freshwater fish are regularly fed brine shrimp - they'd never come across these "in nature" but I'd like to bet that you don't mind them being used to feed freshwater fish. Nor would most fish find microworm or grindalworm or earthworm "in nature" but they are all fed to fish. Most prepared freshwater fish food is made from crushed marine fish - pretty sure my goldfish wouldn't normally feast on whitebait "in nature". There are many foods that a fish wouldn't eat if it weren't in a tank, but it doesn't mean they are inappropriate. This post was for advice re: my sick fish, not to condemn my choice of food as being immoral and inept!

[MatsP]

This post was for advice re: my sick fish, not to condemn my choice of food as being immoral and inept!

I'm not going to argue with you that many of the foods we give to fish aren't their natural food - although earthworms, I believe, are quite commonly flushed down into rivers and lakes when it rains, so that would be a fairly normal food.

I missed an important point in my "objection" (which by the way has nothing to do with morals): Beefheart is very high in proteins. Ian pointed out that he has often seen this in fish that is fed too much protein. I'm sure the high protein content is exactly why your Betta fry are growing well from being fed this diet. However, I'm pretty sure I'm not entirely wrong if I say that Betta's live a fairly short life even when cared for correctly, 2-4 years. Cory's can live for more than 15 years. As a consequence, there is more long term risk of a bad diet to a cory than there is to a Betta, simply because they have more time to accumulate the "badness" of the food.

--
Mats

[bettanbetta]

If that was your meaning then it maybe should have been included in your post to avoid confusion... as you have now explained your reasons (thank you btw) your point is taken...

But, as explained, the Corys only eat the minimal amounts that escape the bettas, who are fed this maybe once per fortnight at most... so don't see it contributing to a high protein diet in the corys really... (not even sure they all get some lol) Also the mix I use is only a proportion of beefheart it also contains spirulina, shelled peas for roughage, vitamins and minerals, and a small amount of carbs and so is not 100% protein as I am aware that nutritionally most fish require less than 40% protein in their diet.

Does anyone know if the Hikari wafers are high protein. My corys used to be fed a standard catfish pellet (i forget the name - small brown pellets in a blue shallow tub) but were moved onto the Hikari about 6 weeks ago.

Coryman - can you recommend a particular type of frozen food for variety as I usually have only bloodworm and beefheart on hand as I only feed it very occasionally. I don't want to increase the amount of BW I feed as I believe that is high protein too.

[MatsP]

If that was your meaning then it maybe should have been included in your post to avoid confusion... as you have now explained your reasons (thank you btw) your point is taken...

Yes, reading your comment made me realize I'd sort of missed a very important point - sorry about that...

--
Mats

[Mike_Noren]

FWIW...
I suggested salt for two reasons: salted water should extract fluid from the bubble, causing it to shrink, and it helps combating some bacteria and protozoa.

The reddish, bloated, belly could well be caused by the diet: dropsy (infection of the intestines) is a typical symptom of too rich or spoiled food in e.g. Tropheus, a herbivorous cichlid.

I've not kept a lot of Cories, but being scavenger-predators I wouldn't expect them to be very sensitive to rich foods, unlike herbivorous fish seem to be. Cories main food in nature is chironomid larvae, after all.

Wrt beefheart, it has been speculated that the main problem is not the protein-richness, but that mammalian fats congeal at lower temperatures than fish fats do. Discus, bettas, and guppies for instance, are typically held at higher temperatures, and seem to do fine on beef, while it is at least conceivable that fish kept at lower temperatures may suffer indigestion or intestinal blockage due to congealed mammalian fats. I can not say whether this is true, but I have seen predatory fish kept in cool water get white, stringy, feces ("fish diarrhea") after being fed minced meat. Anecdotal, but that makes me think there may be something to the temperature theory.


Finally I'd like to thank you for reporting an apparently successful treatment of this disease. Keep us posted.

[Coryman]

bettanbetta,

There are quite a number of frozen foods available, Daphnia, Cyclops Brine shrimp, Muscle Tubifex.

Corys are pretty much filter feeders and and consume all manner of small food items when sifting through the substrate or amongst the Bio-film, which forms on all submerged surfaces, much of which will be low in actual food value.

We open tins, tubs or packets of food the manufacturers tell us are good for our fish and well they might be, some are very good in fact and a lot of research has gone into them, even to the extent that some have been developed to cater for the needs of specialist feeders, even so I honestly believe that most of them are still too rich. This coupled with our nature to feed too much creates the kind of problem you have. In my opinion what your fish has is not a disease but a condition brought on by an inappropriate diet.

Growing fry are a completely different ball game and do need a richer diet, but having said that they still need a good variety for them to develop properly.

Ian

[bettanbetta]

Mike - the salt seems to be doing the trick on the bubble... fingers crossed we can get the little lady back to good health

Mats - thanks.. your comments were valuable once i understod the relevance

Re: foods, I checked the foods I have (and use) for my corys and found the following. The pellet food (King British Catfish pellets) has 50% protein, the Hikari Sinking Wafers 36%, the beefheart mix 20% approx (most fats removed from it) the frozen bloodworm only 8%. So I'll stick with the Hikari wafers for now and check out other prepared foods, bin the KB pellet, and up the number of BW feeds (and maybe add some frozen brineshrimp as I've just found some in the freezer I'd forgotten about)

Coryman - I don't feed my corys the same diet as my bettas/fry, but they do clean up after the bettas they share a tank with. The general diet specifically aimed at the corys is the Hikari prepared wafer, supplemented with occasional frozen BW. I always remove any uneaten wafer 30mins after feeding (very rarely much left as the bettas usually finish up scraps) but will reduce the wafer feeds and up meaty feeds. Do you think this will help??

[Coryman]

I do not use the Hikari wafers so cannot say what they contain, I tend to use Tetra Tabimin and Aquarian tablets as a staple diet supplemented with live or frozen foods.

Ian

[bettanbetta]

Tetra Tabimin contain 60% protein so will have a look at the Aquarian tablets, or stick with the Hikari and supplement with frozen foods.

Thanks for your advice.

[OttoXek]

Plus 1 to Coryman. I found this post a little over a month ago after bubble began forming on the back and belly of one of my red longfin corydoras. I separated "her" in a QT tank and restricted feeding. In the main tank I began feeding a variety of different foods and not just Hikari catfish sinking tablets. After a couple weeks in isolation the bubbles began to go away as did other signs of obesity. I am relatively new to hobby and I am very glad to have found this forum. And especially glad for Coryman's advice!