Oddity while processing rooster: black testes

We are novices at chicken processing, but after doing more than six or so roosters, you kind of know what to expect during the evisceration. Imagine my surprise when a healthy looking and acting 16 week old rooster carcass presented with a pair of black testes. About middling size in the range of the birds, all Jersey Giants, that we processed. Everything else, like the color of the liver, etc., seemed perfectly normal.

I labeled the bag I froze him in just in case, but I am inclined to treat it as an oddity and not a reason to discard the bird. Thoughts? Experience? Wisdom? Has anyone else seen this before?

I can't say I've seen or had any experience about this with roosters, but I do enjoy learning and reading about anything biochem., biology, ecology, or permaculture related. If the testes inside are black and you have more than one rooster and they have gotten into fights before, the testes may have undergone necrosis because of the damage. And you just so happened to cull the rooster before the testes had time to be reabsorbed back into the body which is what some internal organs do when they die (no place else to go). Some other organisms' males will fight and hurt each others' genitalia; pretty much all organisms that produce sexually. I can't think of any organisms that sexually reproduce that don't have males fighting each other. Now, if the scrotum (skin outside covering the testes) of the rooster was black, it may have a gene mutation or two from the Silkie chickens or had scaring and tissue damage from fights or disease. I read a lot about a lot of things and learn about many people would say "what the??" about which is why I plan to do Biochem. in college (or a closely related field). I had to make it clear how weird I am.

DH, being the consummate biologist, fixed one of the black ones and a normal looking one to do a little histology in the lab. He says he can tell if the tissue is undeveloped vs degenerative and which cells have the dark pigment. In his copious spare time, of course. Doesn't every family has a dissection kit?

That's pretty cool DH can tell whether the tissue was undeveloped or degenerative. No, not every family has a dissection kit, sadly; my dad is creeped out by biology. Please may you tell me how DH can figure that out?

He made it sound like basic histology under the microscope, but if interesting, he could throw some techniques his lab has developed. There isn't a good description for the layperson on his lab website of computational molecular phenotyping, but if you want to read some science papers, he explains it all. Kind of like how NASA processes satellite images, only with a microscope.