Over the years I have seen some really strange things on bass, whether it be lamprey or some form of parasite.
But over all these year’s I’ve wondered about the weird black spots I would find on bass throughout the country. One largemouth bass I caught in Lake St. Clair had a black blotch spot on it last year.
While a largemouth bass my dad hooked about 10 years ago on Long Lake had pinhead sized black spots.
Both conditions were super weird!
So I decided to do a little detective work myself on the internet and found a few answers.
Some fishermen shrug the black blotches off as if they are just birth marks, I guess they are in a sort of way. But what really causes it is an increased number of pigment cells in the skin.
So what really causes an increased number, well scientists aren’t quite sure.
With the Douglas Carlson report back in 89, the study concluded that bass collected by biologists using electro-shocking equipment were more likely to have these blotches (23 percent) than those caught by bass anglers (11 percent).
My question to that theory is how does that explain some of the lakes that don’t have electro-shocking, ya konw…? My source for the black blotchy spots can be found here.
As for the pinhead sized black spots? Well that is caused by pigment that the fish deposits around the larval stage of a parasite.
Their life cycle includes birds which pick them up while eating fish. While in the bird the parasite becomes a adult and lays eggs inside the birds intestines.
The bird, via a bowel movement, deposits the eggs in the water. The eggs hatch and the new parasite takes on a snail as a host. Later it leaves the snail and takes on a fish.
The presence of the black spots has not been proven to have much of an effect on the fish except in very small fish if there is not a massive amount of them.
My source for the pin head sized black spots can be found here.
Now you can’t believe everything you read on the internet, but the sources seem to be pretty trustworthy. I wonder if there has been any newer studies on the black spots on fish.