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Redhorse abnormalities

Started by Guest_CNienhaus_* , Oct 18 2013 10:36 PM

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5 replies to this topic

#1 Guest_CNienhaus_*

Guests

Posted 18 October 2013 - 10:36 PM

Hello all,

I've recently sampled redhorse (goldens and blacks) from the North Branch Root River in southeastern Minnesota with some abnormalities.

The following picture is a golden redhorse with a lesion. I'm not a fish disease expert by any means, so does anyone have any idea on what could be the causal agent? My initial thought was an infected lamprey scar, as silver lampreys are known to occur here. However, it very clearly extends onto the pectoral fin.

This is a black redhorse with an unusual coloration that I've never observed. Has anyone seen this before? I noticed an early thread about "colored" black and golden redhorse lips. If it is a pigment issue, could these observations be related? Just a thought.

It is worth noting that at this particular location, there were two additional redhorse (one black and one golden) with observable lesions.

Thanks,

CAN

#2 Michael Wolfe

Board of Directors

North Georgia, Oconee River Drainage

Posted 19 October 2013 - 09:29 AM

Maybe I just don't know my redhorse that well, but I do not see anything obviously unusual in the second photo... what are we looking for?

Either write something worth reading or do something worth writing. - Benjamin Franklin

#3 Guest_CNienhaus_*

Guests

Posted 19 October 2013 - 11:00 AM

Michael,

Sorry about the lack of context. Here is what I would consider a "typical" black redhorse, sampled from the same location on the same day. The fish in question had a mottled, dark coloration dorsally on each side, variably extending down the side. This observation is what is puzzling to me. Does this clarify?

#4 Michael Wolfe

Board of Directors

North Georgia, Oconee River Drainage

Posted 19 October 2013 - 11:50 AM

oh, sure, I see the darkish color coming down off the back and onto the side of the fish now...

Either write something worth reading or do something worth writing. - Benjamin Franklin

#5 Guest_labgirl_*

Guests

Posted 19 October 2013 - 07:11 PM

Does the tissue damage extend onto the fin, or just the redness? The capillaries in the fins are easily ruptured by nearly any stressor in the right degree. Most of the time I see it with very long-finned aquarium species (their tails are bred too long for their bodies to handle and the fibers break), but I've seen it with our fathead minnows too - generally when they're suffering from aeromonas infection when a filter goes down for too long. That bacteria can give physical wounds that bright red, angry appearance for many days after the injury too.