I see these parasites all the time in the local coho. Perhaps as many as one in 6 or 7 fish harbor them.



They show up as subcutaneous nodules, generally along the sides and belly of the fish. Sometimes there are just a few, sometimes a generous splattering, and other times the fish is just absolutely covered with them like a bad case of chicken pox.

Any of you bio types care to enlighten the rest of us on the natural history of this parasite?

Release all of those fish!

Those are entry holes from Sigamoidio Northidius aka arrowhead salmon flesh worm. The worms enter the fish through the skin and reside in the meat. The entry wound heals in the form of small spots and red blotches. Although harmless if eaten, the arrowhead salmon worms are........Nasty!

Oh, yeah almost forgot...one more thing about the arrowhead salmon worms. I made it all up and I'm pulling your leg. Don't know what really causes the spots, just had to rattle your cage a bit because I'm so damn jealouse of all the chrome you've been posting lately.

Oooops, not jelouse....I meant jealous. Must have louse on the brain.....as in sea lice/louse...the only parasite that is celebrated by salmon and steelhead fishermen.

You had me going, you squid snagger, you!

Anyone else with an educated answer?

I'm gonna post this on the other board as well.

Those are coho cooties Doc. They get infected when they get too close to net pens and start messing with those tart Atlantics, who are, after all, Scandinavian and therefore very alluring to native bucks

Salmon cankers. That fish has been playing hanky panky in school.

could be pcb's working there way out of the fish.....the midwest and new york salmon are covered in pcb boils......

Went through this myself (found it on a fish, not me) a while back it is called Salmon pox and is from a parasite called Myxobolus squamalis. They grow almost exclusively in the scales of Coho salmon and not harmful to humans.


PS Kind of a Salmon Acne for fish in thier "teens"

Coho Acne

after all they are going thru puberty at the time.

suspect what you are seeing is the external signs of Heneguya Salminicola. A pertty common parasite in coho. Often see white cysts in the flesh of the fish as well.

Tight lines
Curt

More like puss pockets from the Satsop fish I've seen.

I think Smalma would have a scientific explanation on this.

Henneguya is in the flesh (white postules), Myxobolus squamalis is found almost exclusively in the scales and just under the skin (sub-cutaneous) of Coho in the summer. Not to be confused with Myxobolus cerebralis which causes whirling disease and infects the cartilage of fish

Picture of at: http://www.hancockhouse.com/products/pacsal_pics.htm

BTW: I would think twice about ever eating a fish with the white cysts in case it is Henneguya after reading this: http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=230068

They usually are fine, sea lice are parasites and we all eat fish that had them. The type of scale parasites on the fish I had examined (that look exactly like the ones in the picture above) did not have any type of affect on the meat either... but I have also caught fish with clumps of white "stuff" in the meat that looks like fat (or something) and I used them to fertilize the garden. If you read the link I posted on Henneguya you will see why.

Whatever it is on this fish is something that I do not recall seeing 20 or even 10 years ago and now I have seen this on two last year, and half a dozen this year.

I would kinda like to know what is causing these conditions on fish so much more now than then? Warmer water? PCB's and pollution? food chain? or what? Any ideas or speculation in the bio community?

Henneguya infected meat is not known to cause any disease in people with normal immune symptoms. It looks gross, so I trim away meat that has any apparent mushy white spots. I would avoid eating undercooked salmon, or fish that were not properly smoked (I'm not going any farther with that, that horse is dead and well beaten) to be safe from 20 other potential pathogens, but Henneguya is not something I would worry about.

Unless of course people are routinely looking in your stool samples for spermatozoa.


Klaus, how did you figure this one out? I have trouble enough figuring out human skin diseases, let alone from fish. Great posts. I learned alot.


Link below describes several cases involving human infection with the genus Myxobolus. It does mention the only two known cases where live spores were found in stool samples. It also states that it was incidental, and not the cause of any symptoms.
Journal of Clinical Microbiology


Vince

In 99 we caught two Coho on the same day with the little bumps and missing scales so I had a relative who knows marine biology look at the fish, that is when I was told about Henneguya also.

These both seem pretty common now, but I do not recall seeing either 25 years ago when I worked on a commercial boat and I handled a lot of Coho in the summers.

I believe that fish encountered a tweaker fishing with a shotgun...

Right on the money KRM! Here's that pic folks:


Salmon pox caused by the protozoan parasite Myxobolus squamalis growing in the scale pockets. Often seen on sports-caught coho in the summer. Not yet reported on chinook. Like beauty, ugliness is only skin deep. Parasite harmless to fishes.