My friend caught this largemouth today in a small river. The fish appeared to be in excellent shape, very fat and healthy, except for this huge sore in its side. It was about the diameter of a quarter, and appeared to go all the way through the fish, there was a lump on the opposite side of the fish's body from the sore. It has been a really off year at this particular river and I'm wondering if a disease has something to do with it. 

The lump was right on the lateral line of the fish, you can see some pieces of dead skin where the lump is.

Hmm, I wonder if that's a archery wound? Or perhaps a .22 wound.. Just a guess though.

I don't know..

I was thinking the same thing, looks like he got shot/impaled with something then recovered.

It looks like a lamprey bite to me.

Call Jeremy Wade..........

he got hit by something for sure, just not sure what.  Goes to show how resilient the fish are...and people worry about the slime coats lol  

Attempt at spear fishing ?

It looks like a lamprey bite to me.

X2

lampreys give me the willies.

Great blue heron?

Looks like a hickey from a lamprey. I would rule out a bullet, spear, or arrow because of the ulcer appearance, compared to a clean penetration. Yeah, a lamprey. Maybe someone caught the bass and disposed of the lamprey and later you caught the bass.

Looks like a hickey from a lamprey. I would rule out a bullet, spear, or arrow because of the ulcer appearance, compared to a clean penetration. Yeah, a lamprey. Maybe someone caught the bass and disposed of the lamprey and later you caught the bass.

The giant (3' range) sea lampreys come into this river in the spring but I thought they didn't feed on a spawning run. One of them must have gotten hungry

Lamprey bite by the looks of it

Man those things must have some serious teeth or sucker lips or something.. I've not had the displeasure of seeing one ( lamprey )

I don't know the source of your fish's wound, but I'm going with the consensus:  Lamprey Eel

Most pike I've caught that had sores made by lamprey eels were superficial wounds,

and the eel was never present. The sores were elliptical in shape, and generally pink or straw in color:

 

 

 

           Though I've never seen a pike in advanced stages of infestation,

        the wound does takes on progressively greater depth with passing time:

 

Roger

Geez, those are some Viscious creatures, ouch..

I'm not familiar with a lamprey bite But why would a bite show through to the other side. What if an arrow barely pushed to the opposite side and left an infected wound where it pulled out ?

Warning: Graphic content!

 

lol those bites are nasty!

It looks like a lamprey bite to me.

I second this

I second this

 

Actually, you're sixing it  

My daughter has a three acre pond on her property and I see wounds like this on two or three fish per year. One two pounder had a crooked back and could hardly swim. We found the culprit was a large heron that fed along the shore two or three days a week.

I have seen him take large blue gill and bass up to 14-15". Those he cant swallow he drops on the bank and stabs . When the dogs are out he just moves across the lake.

A lot of salmon and steelhead here have those marks, but they don't generally push out like that.

Great, I just spent 10 minutes on google image search looking at lampreys, freaky

Lampreys are the stuff of nightmares, man, and that almost definitely looks like a lamprey left it's mark.

I have caught many different species with similar markings,they are lamprey boring into the flesh of the fish to basically suck out their blood,we had a lamprey barrier put up here on pike river due to the (up to 2ft long)parasites which are non native to this area,doing a heck of a lot of damage to the native species

 

But yes those are the marks,river vampires as we call em and they can and do some damage to all sorts of fish big and small(the bigger ones have a better chance of surviving as they won'y be bled dry before the sucker gets it's fill)

 

Still nice bass though

 

John