Odd Fungus on Bass Gill Plate 2025

UrbanRedneck reply :

A while back there was a thread on here asking about an odd lesion on a bass gill plate. I took me a while to find this photo and it appears to be the same type fungus that was being asked about. This lake is the only lake Ive ever seen this, and it was only on the gill plates and always round. Very weird.

bigtimfish reply :

I have seen this on a bass before. I took it as an injury to the fish. I did not think it was a fungus.

Paul Roberts reply :

I don't know. Black is common on mouths as bruises from hook wounds. And there is a black spot phenomenon common in some waters -lots of chatter about that around the net. Yours doesn't look hook related as the mouth is clean on that side.

retiredbosn reply :

Is that watermeal on the water in the background of the photo? If so that stuff can keep any photosynthesis happening in the water below the film, and can result in fungal growth in the water. There is some chatter about chleated copper sulfate as a anti-fungal, but if it isn't your lake, then that is a moot point.

Muddy reply :

Thats EXTRA EYE ON THE SIDUS, next question please

Dan: reply :

looks more like an infection than a fungus to me.

UrbanRedneck reply :

What you see in the background is grass in a yard!

No, this lesion was caused by a fungus. It was very common for bass to have this on one and sometime each of their gill plates. We saw this on bass for as many years as I was there (I moved away). Very strange because it was always in the same area of the gill plate and always circular. I had never seen this anywhere else until somebody started asking about it here. I even posted those photos on fish disease forums and nobody knew what it was. A fish disease expert at the local university couldnt tell me what it was (but, he only looked at the photos). Very odd stuff.

J Francho reply :

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A fish disease expert at the local university couldnt tell me what it was (but, he only looked at the photos).

If an expert can't tell you what it is, what makes you so sure its a fungus? Doesn't look like any true aquatic fungal diseases I've ever seen. Looks more like an encapsulated cyst (the dark center), and necrosis from secondary bacterial infection (the pink and white ring surrounding). The fact that it was in the same location is remarkable. I'll try to find some time, and look at my texts for anything in the ball park. it is weird stuff!

Dan: reply :

^the pink and white ring is what made me think it is an infection but then again, I'm only guessing.

DINK WHISPERER reply :

RING WORM

J Francho reply :

Ringworm is a skin disease (fungus) you can get from cats and dogs....not fish.

DINK WHISPERER reply :

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Ringworm is a skin disease (fungus) you can get from cats and dogs....not fish.

Thanks Doc! It was kind of meant to be sarcastic!

Low_Budget_Hooker reply :

Looks alot like a Lamprey bite to me.

Are you fishing anywhere on the colored areas on this map?

UrbanRedneck reply :

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A fish disease expert at the local university couldnt tell me what it was (but, he only looked at the photos).
If an expert can't tell you what it is, what makes you so sure its a fungus? Doesn't look like any true aquatic fungal diseases I've ever seen. Looks more like an encapsulated cyst (the dark center), and necrosis from secondary bacterial infection (the pink and white ring surrounding). The fact that it was in the same location is remarkable. I'll try to find some time, and look at my texts for anything in the ball park. it is weird stuff!

I should have known better than to post this photo, sooo many experts here. The disease expert was my advisor from graduate school, hes a slacker and he only looked at the photo. He did not run tests on it, or try to key it out, or look through the multitude of text books he has. He said it was a fungus, which I agreed, the species of which was uncertain. d**n, you people make it so hard to write brief posts, always want the full blown explanation.

Here, I know what it really was. The fish was caught in a lake in the middle of bigfoot country. I think that is a scar from bigfoot trying to grab it. Yeah, im pretty sure thats what that is. Maybe the infection was from a claw mark bigfoot left on that fish

Micro reply :

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Looks alot like a Lamprey bite to me.
Are you fishing anywhere on the colored areas on this map?

My thought as well.

midnighthrasher reply :

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Quote
Looks alot like a Lamprey bite to me.
Are you fishing anywhere on the colored areas on this map?

My thought as well.

x3 lamprey

Dock Master reply :

You never know, it could be cancer.

Fish Chris reply :

Steve, I'm really surprised that you haven't seen this more often, in different places. I don't know if their is a lake I fish often, in which I "haven't caught" at least a few fish like this. Lots in Clear Lk.

So anyway, here's another 'expert opinion' ;-) I think it is a fungus too, and I believe it attacks this specific area of the gill plate, because there is very little blood flow right there, therefor it's harder for germ and disease fighting agents of the fishes body to protect against it.

I doubt that it would ever be fatal, unless the fish had other health problems, like a weakened immunity system.

Peace,

Fish

J Francho reply :

Quote

Quote

Quote
A fish disease expert at the local university couldnt tell me what it was (but, he only looked at the photos).
If an expert can't tell you what it is, what makes you so sure its a fungus? Doesn't look like any true aquatic fungal diseases I've ever seen. Looks more like an encapsulated cyst (the dark center), and necrosis from secondary bacterial infection (the pink and white ring surrounding). The fact that it was in the same location is remarkable. I'll try to find some time, and look at my texts for anything in the ball park. it is weird stuff!

I should have known better than to post this photo, sooo many experts here. The disease expert was my advisor from graduate school, hes a slacker and he only looked at the photo. He did not run tests on it, or try to key it out, or look through the multitude of text books he has. He said it was a fungus, which I agreed, the species of which was uncertain. d**n, you people make it so hard to write brief posts, always want the full blown explanation.

Here, I know what it really was. The fish was caught in a lake in the middle of bigfoot country. I think that is a scar from bigfoot trying to grab it. Yeah, im pretty sure thats what that is. Maybe the infection was from a claw mark bigfoot left on that fish

LOL, that would have to be the Eastern subspecies of bigfoot, closely related to the lackalope.

I'm no expert, just willing to put in a little effort. Its been a long time since I dealt with fish pathology. I wasn't trying to make it harder for you. I didn't get a chance to look, but I have some good text still, with some decent photos to compare.

Just an aside, I actually had a college professor try to tell me that "Ick" (Ichthyophthirius multifilis) or "white spot" disease in tropical fish was a fungus. I ended up having to write a short paper on the life cycle of the parasite, in other words, a critter, not a fungus. Seems like some of these guys like to call everything a "fungus."

Russ, I thought about lamprey, but location would have to be known.

Bernie Mac reply :

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Quote

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Looks alot like a Lamprey bite to me.
Are you fishing anywhere on the colored areas on this map?

My thought as well...

The shape does look like a lamprey bite.
x3 lamprey

He's in California...I don't think there are any lampreys in his area. Could be wrong tho

WRB reply :

I'm not an expert on diseases, but this looks like a protozoa infection.

Reference; Anglers Guide to Fish Diseases and Parasites, Warnell School of Forestry Resources.

http://warnell.forestry.uga.edu/service/library/index.php3?docID=52&docHistory%5B%5D=1

WRB

J Francho reply :

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I'm not an expert on diseases, but this looks like a protozoa infection.
Reference; Anglers Guide to Fish Diseases and Parasites, Warnell School of Forestry Resources.

http://warnell.forestry.uga.edu/service/library/index.php3?docID=52&docHistory%5B%5D=1

WRB

You could be right. But how does Haemophilus piscium sound? LOL, the name means very little to me, but the picture in Textbook of Fish Health by George W. Post looks very close, as does the description:

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The legion of ulcer disease (caused by Haemophilus piscium) is surrounded by a white to gray rim on necrotized skin and a dark to almost black center made up of tissue debris and blood cells.

I wish I could show you the photo. Its a DEAD RINGER. The text says its common in trout. Makes me wonder if exposure to infected trout is why its prevalent with those bass. If there isn't any trout in the water, then I have no clue.

Anyway, its weird that its only on the gill cover, and most would attack the flesh. Even if it was a lamprey, they fee on blood and flesh, and rarely kill their host. So, they usually attach to the body, and my own personal experience bears this to be true in trout in my waters.

I think WRB has it nailed, though. Some parasite attacked the fish, possibly targeting the gill area, and the rest of that wound is a typical Aeromonous bacterial infection.

That's about as far as I con go. Thanks for showing the picture.

Fish Chris reply :

The most interesting thing to me though, is that of the 500 or so bass I've seen with this, every single one was attacked in the "exact" same part of the gill plate ?

Whatever the culprit is, it sure is freaking selective about what part of the fish is attacked.

One more thing to add.....

It also looks to me that once this critter attacks, it may take a very long time to heal... or it never heals, based on the fact that many of these fish actually have green algae growing on the bony portion of the gill flap, in the center of the attack site.

Hmmmm,

Fish

WRB reply :

Send the pictures of the disease to CA DFG; Terry Foremen or Mike Giusti to identify it, if it's that predominate in the lakes you are fishing.

WRB

PS; don't have any NorCal DFG contacts.

Paul Roberts reply :

Looks like I got one too -from a Colorado pond:

Jake. reply :

I caught one in SW Virginia with the same "fungus" a few weeks back.

The picture isn't great:

12883

Odd Fungus on Bass Gill Plate 2025

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