Habrosus Corydoras and Medications (Barbel Erosion)

[Nautica]

I would like to hear from people who have treated habrosus cories with medications and would like to know what worked ok, and what did not work well in terms of reaction.

I have 5 habrosus cories that have barbel erosion and thought it may have had something to do with the flourite I had added to a small corner of my tank. I had one habrosus cory that grew barbels in my low nitrate tank (5-15), even with the flourite. However, when I first bought the other 5 cories a couple months later, none had robust barbels and one or two had significant loss. Because they were so young (1/4 inch), I thought it was their age. Now, the original one too has lost its barbels and I fear it is not the flourite. Several have now even lost part of the snout and yesterday it was clear that it was some type of infection due to a bloody appearance.

They are still feeding and I have dosed the tank with a half dose of erythromycin (Maracyn) and half dose of minocycline (Maracyn-2) not knowing if it was a gram positive or negative infection. I had six and one died last week, with no other signs than the lack of barbels and dropsy. I am also feeding them crushed Medi-Koi and Metro-Med - which are medicated goldfish pellets. Today, I notice the redness is not there on the one. All have good apetites and are active.

I wanted to dose full strength erythromycin and minocycline, but am concerned they cannot handle it. Should I stick with half strength?

Has anyone managed to put any antibiotic at full strength without killing these guys? How about other cories and otos?

I had added Melafix and Pimafix at full strength last week to see if that would halt it, but it has progressed.

I have also added about a 1/4 dose of freshwater aquarium salt, predissolved and dribbled in throughout the day. They have tolerated this well. I thought it would help replace electrolytes and be soothing to the wounds.

I don't want to lose these guys - it took me a year to get them.

Ammonia: 0
Nitrite: 0
Nitrate: 10
pH: 7.6
Temp: 75F

2 year old, planted 20 gal long with a Penguin 170 and 25 Gal Sponge Filter. Water changes of 20% weekly. Cories are fed high quality diet of Wardley Shrimp Pellets, alternating with Hikari Bottom Feeder Pellets and Algae Wafers, and periodic Hikari Frozen Blood Worms. Other stock:

6 White Clouds, 6 Rasboras, 3 Agassizi Cories (1 showing sudden barbel erosion after 2 years without symptoms), 2 otos, 2 male guppies.

[Coryman]

You mention flourite in one part of the tank but what is the main substrate, for Corys it should be fine smooth grained sand. The chances are the medications are only keeping the secondary infections at bay and cannot do any more than that because the damage is being perpetuated. There are two pain problems with substrate, its either to large or to sharp. With gravel that is to large the Corys cannot get to all the food particles that fall between the grains, which then decompose and rot creating a build up of poisonous gas. It is easy to test for these areas by agitating the gravel with a probe, if bubbles start rising then you have a serious problem that needs immediate attention. The actual problem to the barbels is caused by the Corys having to constant fight the gravel to get at the food. Barbels are sensory organs used to detect and taste food not to be used as tools for shifting gravel, they become tender and open to infection. The same applies with sharp substrate, whether it be large or very small.

Ian

[Nautica]

Substrate is ordinary aquarium gravel - pea sized. About 1/6th of the tank has flourite. I have not had a problem with compaction as the thickness is about 1/2 to 3/4 inch. I gravel vac right to the glass weekly, often removing decorations and plants to do entire sections.

No cory had a problem until I added 5 cories already with barbel erosion. A year prior, I spotted a lone habrosus in an oto tank at the lfs (they didn't even notice it). I purchased her with intent to find more like her. When I brought her home, she had no barbels. Within six weeks she was growing barbels in my tank, with that gravel, including the small section of flourite. I have pictures of the before and after. She maintained those long barbels, as did my agasizziis, until after I added the other five.

It took one year for me to find those other 5 habrosus cories. I brought the five home and quarantined them. Other than having mere stubs for barbels (much like the first one when I brought her home), they had no issues in quarantine. Two of them basically had no barbels. That was about 6 months ago. I hadn't looked closely until about 6 weeks ago when I noticed that my original habrosus was losing hers. Last week one of my agasiziis began a "meltdown" and it is progressing fast.

How do we explain the cories growing and maintaining barbels before I added potentially infected cories? I've had no sickness in my tank in the 2 years that it has been running.

I'm basically looking for feed back on antibiotic use and cories. I would like to understand how well they tolerate meds, especially the habrosus species.

I'm likley going to break the tank down in the spring and will use Eco-Complete. I'm not into sand and tho it may be the absolute best for cories, it is an entirely different experience and one that I really do not want to get into. Sand itself is quite capable of building hydrogen sulfide and anaerobic bacteria, even moreso than gravel.