To me it sounds like liquid expansion of skin cells or a localised water oedema, and that is to do with the metabolism of the fish, its renal efficiency, and its ability to retain osmotic balance. To understand this you have to understand something of the way your fish works internally, so prepare for a whopping great post.lol. Gas bubble disease would be unusual unless you had very cool water temps , simply massive oxygenation, or a co2 system that was overloading the tank.
Such growths with a little fat and liquid in the pocket arent unusual in lionhead goldies for example, but in this region and with a pearlscale I would suspect this fish has some renal issues, quite probably hepatic lipidosis (unprocessable fat retained in liver tissues). With a clogged or partially clogged liver , fish cannot regulate bodily salts and uric acids, and as such even though they excrete many waste products by breathing, its possible for partial liver failure to cause them no end of problems in regulating bodily fluids.
Pearlscales are of course, not a naturally occurring fish, and to create their rather cute and pudgy appearance a massive amount of inbreeding has been done and there are side effects tof their change in form. First major deformities are spinal curvature, and a ribcage area that is massively compressed compared to say a comet goldfish.
This in turn leads to organ compression, pressure on the swimbladder and most of the major organs. This makes the function and growth of internal organs subject to pressure, and even more susceptible to the problems associated with "dwarfing" in more normal bodied fish. ergo, the liver outgrows the fish, becomes compressed in the body cavity and begins to suffer damage and eventually fail.
Now the first thing to make clear is the dwarfing associated with keeping standard goldfish in small aquaria with dodgy water quality does not hold the same implication of abusive care when it comes to pearlscales. Because of their rather extreme proportions pearlscales are likely to run into organ failures with even the finest levels of care, and its not necessarily the fault of the keeper. Firstly, guaging exactly how fat or overfed a pearlscale has become is extremely difficult.Second, because of the pearlscale skin effect their skin does not breathe normally in water, the skin slime production is often a bit dodgy too.Lastly the thing to remember is that pearlscales arent designed to live a long time, comparatively few actually get to full maturity anywhere, and lets be honest , the sight of a truly adult , near melon sized pearlscale is a very rare thing indeed. Most die prematurely, not because of the keepers care, but because over the long term their deformity makes them ill. Some pearlscales are so inbred they can suffer cancer at their first flush of mature breeding hormones. In short, pearlscales are born unhealthy. Its a shame and people often dont realise it, but there it is.
So the upshot of all this is basically how do you handle such a fish in a way that ensures you get the absolute maximum longevity from it, reduce as many of the symptoms of hepatic lipidosis as possible , and help at all times to reduce the impact of the inevitable organ compression?
The solution is simple, but a long term thing, there are no quick cures.
Large cool water bodies with very little nitrate pollution, perhaps keep levels as low as 20 ppm, never use salt with them , as using salt requires a hepatic response from the fish , dont use antibiotics and dewormers unless strictly necessary, as they too metabolise toxins within the liver, and keep the diet very lean , primarily vegetarian, and include no animal protien whatsover.
Think of a successful feeding regime for a pearlscale as if you were dealing with a very elderly animal, who would become ill on a diet that is too rich. In theory its perfectly possible to meet the nutritional needs of a pearlscale, not by feeding them every day as you might expect, but very lightly , perhaps every 3 days, and with foods based on wheatgerm etc, that you might use for feeding koi in the cooler seasons. Basically diet the fish back and keep it fairly skinny.
As for the liquid swelling itself, if it isnt solid or full of pus,personally id pop it,and put a little melafix in the water for a day, but id recommend you seeking vetinary advice on that.
If you can come back with your feeding regime and water qualities it will help enormously as to gauging what this fish needs and is responding to.
For a first step though, starve that fish out for a whole week at least, and make sure the water quality is tip-top.Its about reducing ant toxin impact, from food digestion, fat processing, and handling water pollution impact as much as possible in order to give the liver a chance to heal. Parasite nasties like liver flukes are not impossible but stange as it may seem, you have to get the fish into a fitter state, even if it is sufferring damage from such parasites before you could administer a treatment. Any treatments during hepatic failure are very risky indeed.
Good luck with the fish, dont hesitate to ask with any questions.
Re: Newbie Fish Keeper Needs Help With Ulcers
Looks like your fish have picked up furunculosis, treatment is furan based medications , although they will utterly destroy nitrosoma bacteria,, and force the pond into recycle, you'll not win treating the lesions individually. Oxytetracycline will also treat this infection, but again its another pond bacteria killer. Any way you slice it , treating this will be very tricky indeed. Topical treatments arent halting bacterial progression as you are experiencing, treatments will need to be systemic, and all fish treated at the same time to get on top of it. See what meds your LFS has and get back to us , and we'll see if we can pick an effective yet preferably not too lethal med.
Thats a pelteobagrus fulvidraco, a tawny dragon catfish. Its a slow growing coolwater catfish from asia, it will eventually get to about a foot long. You wont want any fish smaller than 4 inches long in with that one day !
Neon tetra disease is usually characterised by small white patches on muscle tissue, occassionally visible on or through the skin, and sometimes in small tetras the immune response is a concentration of cells in the caudal peduncle, though not usuall on the actual fin tissue. Its quite hard to diagnose, having many similarities to piscine tuberculosis in many of its external symptoms.
As for an occurance of whitespot, conclusive identification will depend on the temperature of your tankwater. Its life cycle can be anything from 3 days in temps of around 84f down to 7-10 days if the water is in the 60's f range. As already suggested protozin works well with goldfish, as does esha exit. Both these treatments may need to be extended to over a week if your fish is living in coolwater to catch the lifecycle of the parasite, because as yet, no effect med can kill the adults. Thankfully adults are shortlived, and we can kill the free swimming stage of the parasite.
Take two day cure quotes with a pinch of salt, they are usually referring to tropical fish being kept at the high end of their temperature range. Ichythyosporidium also have a limited ability to photosynthesise , and depending on whether you wish to accelerate the parasite if you already have treatments or slow it down so that you have time to purchase new meds, you can slow their growth by denying them light. Simply turning your aquarium lights off will help facilitate this.
Should the lumps not reproduce, then diagnosis becomes a little more difficult, odd lumps are often just the odd small fluke burrowing into the skin, or a slime gland that is slightly infected with bacteria, and there is a whole range of trematodia, and crustacean parasites, such as fish lice that will at a few of their 6 phases of development burrow into fish flesh.
Waterlife sterazin will destroy these parasites if used early enough. Beyond that there are other diseases such as cauliflower disease which will appear as small lumps to begin with. With goldfish, being that red skin cell cancer can be so prevalent in inbred fish, there is alwas a risk of tumour, whether they happen to be malignant cancers or not. Some goldfish also get periodic lumps based on hormonal activity, not always on the gill covers as some might suggest.