Corydoras Schultzei Black white/grey fuzzy spots

[Supercoley1]

Hello. I have a group of 4 Cory Schultzei Black that have been in my tank since September last year (8 months) There were 6 but 2 died in the first month.

There is 1 female and 3 males. They were breeding prolifically until about a month ago spawning every 5 days or so but since have not seen any eggs!!! She is looking pretty swolen and I assume she is due but that isn't the problem I am worried about although it may be a side issue caused by something else.

The problem is that of the four Corys only one male looks perfectly fine, the other 2 males have white/greyish fuzzy marks on their sides and being black it is quite noticeable. The female looks like she may be getting one but if it is indeed the same it is very small at this time. They feed perfectly well and are active. They breathe heavily sometimes and then other times they breathe at a much slower pace (all in the same day.) They have a sand substrate and barbels are looking very healthy. On a few occasions I have seen them 'flicking' their sides in the sand but it is not a continuous thing. They do it and then go back to normal for hours!!!

The worst affected hides at the back of the tank and in the corners for most of the day.

These are the tank parameters I can tell you:

1. Water parameters
a) Temperature range. 25-26ºC
b) pH. 6.4 - 7.2 (CO2 injection during the photoperiod)
c) GH. No idea on these 2 but my water report says it is hard water aroundd this area. I am told it is around the 6-8KH region
d) KH
e)Ammonia, Nitrate, Nitrite, levels. 0, 10-20ppm, 0
f) Water change frequency 50% weekly
(Most LFS's will check your water and give a list of readings).

2. Tank set up
a) Size. 33USG L-80cm D34.5cm H45cm
b) Substrate. fine sand
c) Filtration. 700lph external with ceramic rings, bioballs, coarse sponge and purigen.
d) Furnishings. Fully planted with some cobbles and redmoor wood
e) Other tank mates. 17 x Rasbora Espei, 2 Otocinclus Macrospilus
f) How long has it been set-up? nearly 3 years

3. Symptoms / Problem description
As above

4. Action taken (if any)
1 x extra 50% water change each week on top of the normal 50% weekly. No meds administered as yet

Does anyone have any ideas on what the problem may be?

Thanks in advance
Andy

[syno321]

I don't propose to be an expert, but my guess is that this might be velvet?

[Coryologist]

I have seen this on the foreheads on many of my "Blacks," over the years, though I have not seen it in any other fish in my room. Observation with a magnifying glass shows what looks like a tiny worm, in a cluster which resembles peach-fuzz. A 2 to 3 day treatment using Formalin 3 eradicates the problem, but it does return at various times. It is a minor annoyance and I have never had it affect the overall health of any of the fish in question.

Can't tell you what it is or why it only affects the Blacks, but the Formalin 3 does the trick, each time it appears. I have about 6 tanks of Blacks and have not had an outbreak in probably 6 months. I currently use Formalin 3 as a prophylactic in all my tanks, once a week. That is probably why it has not returned. FYI - I double dose any tank housing livebearers as it seems to keep them from developing any of the myriad illnesses they are susceptible to.

It's rather pricey, so I purchased 4 - one gallon containers of 33% Formaldehyde solution and make my own by cutting it, 11 to 1.

Hope this helps. - Frank

[Supercoley1]

I'll have a look for some then.

A further update. On the one that is worst affected although still very active and still alive (which is why I don't think it Columnaris)the 'growth' is on the body just behind the gill (on the skin not the gill) and it is starting to look like a small 'limpet' meaning it is like a bump that slightly protrudes from the fish.

Is this OK?
http://cgi.ebay.co.uk/Formaldehyde-40-F ... 1|240:1318

One thing I do have is Panacur from the days when I had Rams which had the dreaded Cammallanus (before this setup and before these fish) That is 2.5% fenbendazole. Could this work whilst waiting for the Formaldehyde or is it best to leave it be and just do water cahnges for the week waiting for delivery? ;)

Many thanks

AC

[Coryologist]

Doesn't sound like the problem I get. Yours sounds significantly worse.

That formaldehyde is fine as long as you dilute it around 12 to 1, or so. Good luck. - Frank

[Supercoley1]

Frank

I have had the same sort of things as you have had I think. They often seem to get grey areas which come and go of their own accord. I guess the amount of water changes and health of a heavily planted tank help out here. This is one reason I guess why I didn't think too much of this outbreak. It was only when I wondered why there hadn't been a spawn for so long that I started really looking at the fish very closely and noticed that the usual blemishes were looking a bit heavier than before. Almost like lesions.

I remember reading a Neale Monks post r.e. Otos latching onto slower moving fish. Mine don't do that but sometimes if the Cory and Oto are after the same food. algae pellets and such like I see an Oto 'jump' onto the Cory's back.

this was the thread that he posted on with the comment:
http://www.fishforums.net/index.php?showtopic=35094

Could it be that the Otos are making a wound which is causing a secondary problem of parasites? After all I have seen this several times before knocking on the glass at which point both the Cory and Oto seperate and go their own ways.

On the formaldehyde 12-1 mix what sort of dose do I add?

I have a 125Ltr tank which I guess has about 100Ltr of water in it.

AC

[Coryologist]

Hmmmmmmm. That's an interesting concept. I would think it plausible, but I'm sure that there are others here who keep that type of fish that could give you a better idea of the likelihood.

At a 3% solution I use 1 tsp per 10 gallons. I hope it works for you. - Frank

[Supercoley1]

I will let you know.

Many thanks.

AC

[apistomaster]

I can't believe that Otocinclus would or could damage a Corydoras.
The Corydoras would have to be past the point of no return before Otocinclus could even momentarily 'taste' the skin of a Cory.
I've been around this bush regarding Otocinclus and Discus and just because one might briefly attach itself to a discus I don't buy them causing harming Discus either.
Now Sturisoma and Discus is a different matter. They have amply proven to me that they have the willingness and ability to scrape and damage the skin of Discus and can become relentless in their desire to sample Discus skin/slime.

[Supercoley1]

I think I've cracked the problem here. The spots are on all the Corys now and on the worst affected it is indeed looking like fluffy white fungus. Should I chuck some Melafix in while I wait for the Formaldehyde? Can't hurt I assume.

Another thing that seems to have happened is cloudy water!!! This tank has been undisturbed since ealry March (I rescaped it then) the substrate is the same substrate that has been in there since September 2007 and I just rescape the plants, hardscape etc.

Water was initially cloudy due to the substrate but cleared after a week or so of multiple water changes. However over the past few days there is a milkyness to the water. Its not particles that I can see and I assume this is a bacterial bloom.

However being a planted tank it gets 50% water changes weekly normally (currently 50% twice weekly due to the Cory's problem) therefore I can't see it being bad water quality. Running a 700lph external filter on this 125Ltr tank and it also has purigen in it so there shouldn't be any ammonia problems. It also shouldn't be an overfeeding problem as there is a colony of shrimp and snails in there which sweep up almost anything. I did a 50% water change at 12pm today and just 3 hours later the water is cloudy again. It probably wouldn't be that noticeable to someone who saw the tank but to me it is instantly visible as I am used to the water being virtually invisible

This is the first time I have experienced cloudy water except for particles just after rescaping so I am quite confused why it should just have appeared out of nowhere. I asume it is no coincidence that the Corys problems arose at virtually the same time

Any thoughts on this. Am I assuming fungus when as Frank said above it could be a bacteria/parasite. Could it be that the fungus has been triggered/helped by a bloom? And why would it suddenly occur?

AC

[Coryologist]

Hi. I think Pimafix is the treatment of choice, between the two products, for external problems and Melafix for internal. I think I have that right.

Your problems have reached the point of being way above my pay grade as I am blessed to only have the occasional Cory that gets stricken with anything major and not very often at that.

Rather than give you suggestions that may only worsen the situation, I'd prefer to let some of the more experienced individuals suggest a treatment plan for you. I am sorry I could not offer more concrete advice, but I just don't have the requisite knowledge to effectively assist you with this and I would feel very badly, if, after taking my advice, you lost your fish.

I'm sure someone will pitch right in, to help you diagnose and treat your problem. I hope all works out for you. - Frank

[apistomaster]

Did you use a bottom layer of soil under the sand?
I know it is somewhat fashionable to do that in planted tanks these days but I can only think this style of aquarium as a ticking time bomb. It sounds like you now have a bacterial bloom of unattached bacteria. These can be fairly persistent and even repetitive water changes only seem to provide temporary relief and if anything, the fresh water seems to feed the bloom. I am fighting cloudy water in one tank where I have been using an increasing amount of RO water reconsitituted to 50 ppm TDS. Other tanks undergoing similar water changes haven't clouded up and this one has persisted for a month. It hasn't caused any losses, yet. I have 50 L134 fry in a 40 gal breeder. I have no more than 1/4 inch of FloraBase. Florabase is dusty if disturbed but it also has a static charge that usually helps settle out fine clouding particles through flocculation then they sink harmlessly to the bottom.
Such a bacterial bloom condition is conducive to diseases if it really is a bacterial bloom. My cloudy tank has a good, earthy smell unlike one that is truly going bad.
I would treat your Black Corydoras in their own bare hospital tank for no more than 7 days. Up to a tbs of rock salt/gal and enough methylene blue to obscure the fish is one of the most gentle ways to treat the catfish. I don't think the fenbendazole/flubendazole are likely to have any effect on this skin problem but it isn't toxic so you could try some while you are at it. If you do have a soil base I would eliminate it and rely on substrate fertilizer tablets. It has never made much sense to me to add fertilizer to the water since substrate fertilizers go right to the roots and enough dissolves for plants able to directly extract fertilizers from the water to be able to do so without any regular dosing of the water. Few rooted rosette type plants are able to directly assimilate dissolved fertilizers. Many stem plants are able to do so.

I hope something works and your problem is resolved. C. shultzii is one of the Corys I want to try one of these days and Corydoras C-121 again.(Lost mine).
I am only working with C. duplicareous, C. sterbai, C. habrosus, C. hastatus and Aspidoras pauciradiatus. I have a trio of possible Aspidoras fuscoguttatus.
This isn't something for which I would expect Melafix to be effective. Actually, I haven't had Melafix nor Pimafix help any fish I have treated with them. I know others have reported good results but I probably have more faith in "real" drugs.

[Supercoley1]

I don't have a 'nutrient rich' substrate as such. It is the Tropica brand one which is a clay based substrate with high CEC and it takes nutrient in and stores it rather than being a substrate that is nutrient rich when added.

On top of that is an inch of sand.

I dose EI daily which I have done for a long long time yet all of a sudden the problems arrive!!! I won't get into an argument on water column versus Root tabs versus substrate ferts etc. I think that would sidetrack the issue. There are so many disagreements on the planted side of things. lol

I don't have a hospital tank!!!

All the other inhabitants (Otos, Rasbora, Shrimp and MTS) show absolutely no sign of a problem!!!

I think I will have to try a fungus remedy tomorrow and then see what happens. The Formaldehyde is ordered but knowing ebay could take a week. All the Corys are still fine and active at present so I assume it isn't a huge problem for a few days at least.

Will let you know.

AC

[apistomaster]

I don't think most fish meds work very well in well established aquariums. The abundant organics tend to blunt the efficacy of most meds and/or some meds wreak havoc with your well established biota. You have a lot of work already into establishing your well planted tank so it would be a shame if any fish meds harmed it.

In a pinch, a clean 5 gal bucket makes a serviceable treatment vessel. One week is usually a long enough treatment period to take care of most treatable conditions. I would only use an air stone and heater. Changing the water at 25% each day and replacing the lost meds treats the targeted disease and avoids ammonia/nitrite problems.
Formaldehyde solution(Formalin) is stressful to aquarium plants, ime.

[Supercoley1]

I managed to get a few pictures of the (now former) worst affected fish. One of the other males now has large grey/white 'discolourations' along his body. The female is currently the least affected although she looks like she is about to burst with eggs!!! All these marks seem to start in the area where the females nose goes in the T position although again that may just be coincidence

The problem I have is that although it is well established and planted which does take some work, it also means it is impossible to catch fish (especially bottom dwellers) without removing everything!!!

The second and third picture show the original infection just behind the fin behind the gill. These pics are all the same fish:




And this is why it is so hard to catch fish :


I will try but I have never succeeded before. lol. Hard enough to catch them when I empty the tank apart from substrate when I rescape

AC

[Richard B]

How deep is the sand substrate? In the middle 2 pics in the last post it looks quite deep & a little compacted -i wonder if any unpleasant gases are building up & remaining trapped causing deterioration of the quality of the living conditions?

[Supercoley1]

The sand is about an inch thick. If you look at the pictures the sand is yellow and the 'clay/Leonardite' mix below is greyish.

Anaerobic substrates is something of a no go area in planted these days Some of the 'respected' people say either there is no such thing as an anaerobic substrate in planted tanks due to plant roots bringing O into the substrate and others say anaerobic substrates provide the ideal habitat for a planted aquarium.

I tend to believe that anaerobic substrates do exist, that they are ideal habitat but I also believe that the plants roots bring O in as well. Never had this problem before and I've done it this way for a long time!!

AC

[apistomaster]

The pictured fish do appear to be suffering distress and some kind of disease condition but I don't know for sure what it is.
They look more like newly imported specimens than fish you've had a few years.

This condition is usually related to sustained stresses caused by a combination of stressors. Some to consider are elevated ammonium, nitrites, exposure to chilled water, drastic pH changes and excessive waste products have accumulated within the substrate.. None of which sounds like something you have done or caused.

I would be sure the aquarium had a thorough substrate vacuuming of any accumulated crud or detritus and make a few 50% water changes within a few days of each other. It could be that there is a good deal of accumulated wastes in the substrate that needs to be physically removed with a siphon/gravel vacuum. Your last post addresses the dirty substrate issue. It is not always clear cut and some substrate vacuuming is always beneficial except it does result in a mixing together of the materials you used. Not harmful, just different than how you decorated.

Because these Corydoras have very general symptoms, perhaps it would be best to use the 5 gal bucket treatment vessel I described and proceed to treat them with formalin and malachite green in water with 1 tbs/salt per gal.
Also treat them with PraziPro and the Panacur for nematodes and flukes across a wide spectrum.
Feed them live clean black worms to help build up their health and to help keep the treatment container cleaner than it will be if prepared foods are used. Live worms are very helpful in promoting good conditions and health among Corydoras spp.

[Supercoley1]

I actually got them in September last year and they were nearly adult then although the female was still a similar size to the males. She is massive now!!! Looks like she is about to explode but looking closely at her she shows no sign at all of these symptoms!!!

She is also the worst at digging around so I would've thought she'd be first to suffer ?? Maybe she is just healthier than the others.

Today I did a 60% change at 12pm and at 11pm tonight I did another and the water is clear. Will see what it is like tomorrow.

The Purigen should be taking care of any ammonia in the tank and when I last cleaned the filter out a week ago it was only 'half brown' and was only 'recharged' about a month ago.

I will see what I can do r.e. catching them but like I said that normally means total removal of the plants

Will look out for live foods. Not easily available to get here in the UK IME unless your keeping your own cultures.

AC

[Supercoley1]

Just an update. After noticing some ragged tails and white barbels I started dosing Fin rot and Fungus med on Monday night whlst waiting for the Formaldehyde (which arrived yesterday.)

Last night I noticed they were looking 'more black' with less 'greyness' to them.

This morning (only 36 hours after starting) I saw a writhing group of 4 Corys all over the tank and lo and behold they were spawning again. Most of the whiteness is gone but little patches remain. the female is still unaffected

That's the good news. the bad news is that she was saving for a month and there must have been 200+ eggs which took over 2 hours to remove (they were everywhere.)

I am going to continue the Finrot and Fungus treatment until all the 'symptoms' have gone and then I will use the diluted Formalin mix for a few days/week to make sure that whatever left them susceptible to the fungus is eradicated. Will the Formaldehyde affect the eggs? They are in a net within the same tank.

I must add I treated the actual planted tank because if the Corys were so bad then whatever caused it may have spread to the other inhabitants (without being visible) yet.

So good news Hopefully I'll have some little babies soon. I have had little success with previous spawns only raising 1 fry to 2 months (2cm or so) and he/she died for no apparent reason a month ago. Probably from the original cause of the current problem.

Will let you know if anything comes back etc.

Many thanks for the help too

EDIT- They didn't finish when I thought they had. Just picked a load more out. She normally spawns in the morning 4 hours or so before lights on and finishes before lights on. She started about the usual time but saw them still thrashing about 8 hours later!!! The count is about 250ish (see pic below) I started counting but was up to 120 before getting to the bulk of the eggs on the right And only a few white ones so far. I may have to get a 1000 gallon tank. lol

Got a couple of pics of them whilst they were on the job (pre lights so used the flash) All 4 are in the same corner for these pics but they are moving so fast that each time I only got 2

In the first pic on the right you can clearly see the rot on the tail of the fish escaping from the picture. The second picture is a different fish but again the tail has some damage. the female is huge and the one staring up at the camera whilst spraying sand everywhere. She has gone from a size 24 to a size 12 in the space of 10 hours so a new wardrobe is going to be needed





Andy

[Supercoley1]

On the adult front the blacks are slowly losing the greyness but 2 of the males have substantial damage to the lower half of their tails and 1 has shortened barbels. I have been dosing the Formalin mix now for 3 days and will continue through the next week.

Will this kill off beneficial bacteria too? and will it kill off the fungus causing the tail rot as well as bacteria that gave the fungus the chance?

On the eggs front this was the largest spawn by far (250+ eggs.) They started hatching before the third day had finished and now at the end of the fourth day I have never had so many wrigglers. I don't think all the fertile eggs have hatched yet either. Not a chance of being able to count the fry though. lol

AC

[Supercoley1]

Just an update on the situation here. All things seemed to be good and all 4 Corys were 'back to black' and the tail fins on the 2 worst affected males starting to regrow. The other male and the female had no rot, just fuzzy grey patches. Pimafake and Melafake were dosed for the week following the Formaldehyde mix. Then the next week was just Melafake.

A month on and within the space of 4 days the 2 previously affected males suddenly died off No sign of anything wrong with them but I guess it was something internal. I dosed the Formaldehyde mix again straight away. I think I will go with Frank's suggestion of dosing it weekly 'just in case'

The remaining Male and Female who had no rotting are still alive and looking fine. I just hope that they don't die off.

There have been no more spawns since the monster spawn in early May however the female is almost bursting again now. This tank is currently getting twice weekly 50% water changes. Will go back to one x 50% weekly when I am confident that the problem has cleared.

On another note I had some Cyano problems with the Fry tank I setup and all but 1 of the fry died off. He/She is now 1½months old and he/she is in the pics below:

This tank (shock horror for you guys. eek) Is a 10Ltr. Non CO2 injected. NO water changes. 20x lph turnover (200lph external) and breeding cherry shrimp for company. All seems well and he/she is about 2cm long







AC

[Supercoley1]

Just thought I'd post another picture. A lovely Oto there ;)



AC