The merchants realised how well pink coral would show up against dark pigmentation.

Lower pitchers typically have a very dark pigmentation, being purplish-black throughout.

The general trend is for a darker pigmentation the farther north the species is found.

There is scattered dark pigmentation across the rest of the body.

The dark pigmentation is lost during the breeding season and regained later.

They are mainly red in colour, with slightly darker pigmentation on the head.

More specifically they are referred to as the black sea turtle due to their unique dark pigmentation.

They have a layer of dark pigmentation just below the surface on each scale that enhances the iridescence.

"It was only later that we lost our hair and at the same time evolved an evenly dark pigmentation," she said.

The mantle is black, or shows dark pigmentation.