Help! Sick banjo catfish with cyst or growth

[bekateen]

Hi All,

About 2 months ago, I purchased a medium-sized male banjo catfish

Bunocephalus coracoideus

. I've never noticed anything unusual about it until yesterday, when I observed a large, bright orange mass on the underside of its chin (see pictures). I've never seen a fish with this before, so I don't know what it is or how to treat it. My initial guesses as to its cause are (1) a fluid-filled cyst, (2) a bacterial infection with an abscess of pus, (3) a parasite-filled cyst, and (4) a tumor. The bright orange color suggests to me the bacterial infection or parasitic cyst. Since it's the middle of the work week for me, I won't get to do anything dramatic like try to cut it open until at least the weekend. The fish seems to be in otherwise good health and it's eating well (you can see that it's not lacking in body mass in the photos).

Here are the tank parameters: (using a modified version of Coryman's list of info requested in the Cory forum)
1. Water parameters
a) Temperature range 78F
b) pH 6.5
c) GH - not measured
d) KH - not measured
e) Ammonia - 0, Nitrite - 0, Nitrate 40-80
f) Water change frequency: 50% change weekly.
g) Routine water treatments: When water changes occur, the tank is treated with SeaChem's Neutral Regulator and Discus Buffer to adjust pH and neutralize chloramines, and Aqueon water conditioner.

2. Tank set up
a) Size: 36 gal.
b) Substrate: playsand.
c) Filtration: Aqueon QuietFlow 50 powerfilter
d) Furnishings: Driftwood, lots of plants, PVC pipes, 2 nylon spawning mops, and a decorative Blackhawk Helicopter
e) Other tank mates: 8 C. aeneus, 5 C. trilineatus, 5 C. agassizii, 1 C141, 4 other banjos, 1 upside down Syno, 3 clown plecos, 2 albino BNs, 3 penguin tetras, 2 white clouds, and about 17 Apistogramma agassizii.

f) How long has it been set-up? The tank has been running for about 3 years

3. Symptoms / Problem description: Described above

4. Action taken (if any): None yet, other than to contact my PC support team { that would be you folks }

5. Medications used (if any): None yet

6. Recent changes in the tank: About one week ago, I collected some plants from a friend's outdoor pond, then washed these and introduced them to the tank. Even though I washed the plants and their root systems vigorously under tap water (before adding them to the tank), I still observed a few small (4 mm) krill-like invertebrates clinging to the roots and then swimming away after I added the plants to the tank. At the time, I became concerned that the plant may be carrying potential fish parasites, but alas, I didn't consider that before adding the plants to the tank. Hopefully that's not what I'm seeing.

Any help you can be would be greatly appreciated.

Thanks, Eric

[bekateen]

Bump. Any advice as to cause or how to treat?

[Jools]

It doesn't look like a disease to me. Is the banjo feeding?

Jools

[bekateen]

I haven't seen him actually eat, but his body shape is full without looking swollen, and his activity level seems normal... normal for a banjo cat, anyway.

[bekateen]

Okay, I tried a simple surgical removal of the mass: I anesthetized the fish in 0.1% benzocaine dissolved in a sample of the fish's original aquarium water; I let the fish swim in this anesthetic solution until the fish became unresponsive to my touch (this took about 10 minutes). I placed the fish belly-side up on wet paper towels and covered its body with another wet paper towel, exposing only the head.

I cleaned my surgical tools (a scalpel and tweezers) using rubbing alcohol and then I passed the tools through the flame of a butane lighter (if you try this in the future, be sure to hold the alcohol covered tips of your tools down below your fingers, because if you point the tips up, the flame will ignite the alcohol and it could flow down onto your hand... never a good thing).

Since the mass was near the operculum, first I tried to look inside the gill cavity, but I could see nothing. Using a small scalpel blade, I poked a 1mm hole into the skin where the mass was most bright yellow-orange in color (meaning to me that whatever was inside was closest to the skin surface). I pressed on the mass using tweezers and immediately small granular things began to pop out of the mass. It was the aquarium sand! Some of the sand appeared to have hardened into a solid mass, but most of the sand grains were loose. There was no visible pus, and no "visible-to-the-eye" parasites in the mass. However, the skin tissue in the area was notably red, indicating inflammation and possible infection.

I used the tweezers to push out as many sand grains as I could see, and then I used a syringe with a 26G needle to squirt water into the now-collapsed cavity where the sand had been, which caused a few more sand grains to come out. I repeated this wash several times, until no more sand came out.

On the advice of a LFS owner (not any of the LFS I have ever mentioned in any other posts I've written on this website), I cleaned out the cavity by flushing it two more times, but now my syringe was filled with a little alcohol-based mouthwash - specifically Listerine Ultraclean with "Everfresh Technology" (although I don't expect that the fish cares about this).

I transferred the banjo to a recovery tank (a 3 gallon tank which has been running for months) and within a few minutes the banjo was awake and swimming around, so I know the benzocaine had worn off.

I will be treating the fish with antibiotic for a few days until the wound is no longer visible. The only antibiotic I have at home is clindamycin, so I will be using that once per day at a dose of about 15 mg/gal (that's equal to the label's recommended dose of 150 mg/10 gal).

So what happened to this poor fish? I'm not exactly sure, but apparently it probably inhaled some sand grains when it was burrowing or foraging in the sand and these became lodged somewhere in the gill cavity and created this cyst. Two things still puzzle me: (1) why did this happen to this fish, but it's never happened before to any of the other banjos in the tank, which we've had for almost 3 years now? and (2) how did the sand grains create this pocket under the skin instead of being stuck in the gill cavity under the operculum, where they might have been flushed out by the fish through its own natural breathing?

Okay that's what I can tell you. Now I just have to watch this guy and hope he recovers.

If you have any feedback or advice, I'd like to read it.

Cheers, Eric

[Jools]

Fascinating. Banjos are known to skin shed, which means they must grow new skin. I wonder if this is how the sand got trapped? They are not designed to live in sand (not that I thought it did them any harm) and perhaps skin shedding while burying in sand carries this risk? That said, I've never seen this problem before.

Jools

[bekateen]

They are not designed to live in sand

Really? If true, that would surprise me (unless by "not in sand" you actually mean that they should be "in mud," which would then totally make sense also). We didn't know anything about their natural behavior when we first bought them years ago, but everything about them seems (to me) to fit the anatomy and behavior of a burrowing fish: in particular, their fright-reaction (if you startle them, they rapidly swim nose-down into the substrate and attempt to wiggle themselves into it (in our LFStores, the banjos also do this, or at least try to, even into pea-sized gravel), and their dorso-ventrally compressed body makes this even easier- when they dig into the sand, they slice into it without effort. Also, their feeding behavior (see story about juveniles below).

All of our banjos (I think we have 6 now) do this. They hide in the sand all day long, with only their eyes and mouth sticking into the water (see pictures) and sometimes their tail not fully buried, and then at night they emerge and swim in the open water. Unlike our plecos, they never attempt to hide for the day in caves, cracks or wedges amongst the driftwood, rocks or the decorative Blackhawk helicopter available. I mean, yes they will explore these places, and sometimes stop for a few minutes or an hour, but they will then return to the sand later the same day.

Under normal conditions, they rarely emege to feed in daylight, I suspect because they are well fed. But when we raise the fry, the young will sprint out of the sand and attack balls of live tubifex worms in daylight, then hide again when finished. From an animal behavior perspective, banjos look and act like perfect "sit-and-wait" predators.

Yes I've seen them shed their skins before, and that may have something to do with this problem. But I am most struck by the fact that the sand was embedded right beside the operculum, so I think the sand got in from inside the gill cavity, not from the outside skin. I just don't know how/why it got stuck.

It would be nice if the fact that they shed and regrow skin is an indication that they will also recover from surgery fast and well.

Thanks,
Eric

[Jools]

Yup, you got it, they are found in leaf litter over thick mud, or at least the

Bunocephalus

I've found in the wild have been as such. I'm not saying they should not be kept in sand, just that they are not perhaps as evolved for it as one might think given their instinctive burrowing.

Jools

[bekateen]

Good to know. Thanks!

Eric

[bekateen]

Hi All,

Well, it's been two weeks since the surgery. As stated before, I treated the banjo with an antibiotic daily for one week. After this I left the fish in the recovery tank one more week, and then today I returned him to the community tank. But before I did, I took another photo to document his recovery.

The wound is all healed; I cannot see any redness or any residual sand in the place where cyst (or whatever it was) used to be. The only trace remaining is a darkened discoloration of the skin where the cyst was located.

Now that this guy has returned to the community tank, I hope that he gets back to normal.

By coincidence, yesterday I also changed out all the old fine sand in that community tank for a slightly coarser variety (and I mean just barely larger) in order to reduce some complications I've had with my power filter, which was prone to suck in the smaller-grain sand that used to be in the tank whenever a fish disturbed the substrate. Hopefully, this also helps prevent the sand-cyst as I'm calling it from forming again. My only worry now is that this coarser sand may alter the typical burrowing behavior of all my banjos, which in the past were pretty good about spawning in the tank about every month or two.

Cheers, Eric