So they're not lice. They're Black Spots. Readers who are better websearchers than I found
apophallus brevis on the Maine Inland Fisheries and Wildlife site and
apophallus brevis is what I found on the trout I caught at Quimby Pond last week. The state's Fish Health Laboratory in Augusta says the black spots on the fish are "usually caused by a small immature larval trematode parasite," the aformentioned
a.brevis.
Parasites have developed the most amazing survival strategies, and this one is no exception. The life cycle of
a. brevis involves the fish-eating Common Loon, whose mouth plays unwitting host to the adult worm, which lays eggs which pass through the loon into the water where the eggs hatch into an intermediate stage, which finds a mollusc to live in (and sponge off) until it develops into something called a redia, which produces another Latin name,
cercariae, and that Latin name goes out and catches a fish. And then it's heigh-ho the derry-oh, the loon takes a fish, and do you begin to detect a circular pattern here?
The fish scientists also tell us that
a. brevis does not infect humans, that cooking the fish kills the parasite, and that if enough of the little buggers latch onto a trout they can kill it. As the trout I caught were fairly covered with black spots, and still fought like tigers, I assume they had not been attacked by enough parasites to cause mortal injury. But they were not a pretty sight. You would not take a fish like that to the prom.