Why is this the answer?

The answer is lobster because this fun riddle is a clever way to describe one of the most interesting creatures in the ocean and what happens when we cook it to eat. The riddle plays a trick with the colors we see, and the answer is hidden in the way lobsters change color. Let us look closely at the first part of the riddle: "What goes in the water black…" When a lobster is alive, it does not look red like the pictures you often see in restaurants or books. In the wild ocean water, lobsters are usually a very dark color. They can look black, greenish-brown, or a deep, dark blue. This dark shell helps them hide safely amongst the rocks and seaweed on the ocean floor. This natural camouflage is very important for them to stay safe from other animals that might want to eat them. Think of it like a superhero wearing a secret, dark outfit to sneak around without being seen. Now for the second part of the riddle: "…and comes out red?" When people catch a lobster and cook it to prepare for a meal, they place it in boiling water. This is where the amazing color change happens. The lobster's shell actually contains different color pigments. The dark colors are mostly on the outside, and the bright red pigment is actually hidden underneath and connected to a special protein. When the shell gets very hot from the boiling water, the heat breaks apart the protein that holds the dark color. But the bright red pigment is much stronger and stays put, becoming the only color left. It is like an invisible red paint is suddenly revealed on the shell. This scientific trick of nature is what makes the riddle work so well. So, the lobster starts off dark, looking almost black or brown in the cold ocean water where it lives. It has that dark color for protection. Then, after being in the hot water for cooking, it turns a bright, beautiful red, just as the riddle perfectly describes. This makes the riddle a wonderful, tasty puzzle to solve.