system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: why do crustaceans turn red when steam/boiled/cooked?

Have always been puzzled about why they specifically turn red no matter what Color they were before they were cooked.
gpt
The shells of crabs and lobsters contain a pigment called astaxanthin. This pigment absorbs blue light and causes a red slightly yellowish color.

When the crab or lobster is alive, another pigment called crustacyanin wraps the astaxanthin and influences the light that gets absorbed, giving it a blue greenish color.

When cooked, this pigment bond falls apart and the shiny red pigment of the astaxanthin comes through.