Brittlestar A bright red brittlestar clings to a coral head in the Flower Gardens National Marine Sanctuary in the Gulf of Mexico. Sea stars get their name from the five-armed varieties, but species exist that have 10, 20, and even 40 arms.
Lionfish A lionfish peers through the glass of a Las Vegas aquarium. In the wild its beautiful, needle-like dorsal fins can deliver a painful and venomous sting. The formidable array of fins, combined with the fish’s color and generally prickly appearance, are meant to send a strong “stay away” message to predators in Indo-Pacific coral reefs.