The Common Starfish (Asterias rubens) is also known as the Common Sea Star, because it is not a fish. It is a marine (saltwater) animal.
The Common Starfish is usually orange or brown. It has five arms that are broader at the base and become narrower at the tip. It has soft mounds called papulae on both the top side and underneath.
It measures about 10-30 centimetres (4-12 inches) long.
The Common Starfish is the most common sea star in the north-east Atlantic Ocean, from Norway in the north to Senegal in the south. It is not found in the Mediterranean Sea.
It feeds on molluscs and worms.
The Common Starfish is diocious, which means that each individual is either male or female. The female releases eggs into the sea. She has about 2.5 million eggs, and most of them are eaten by fish.
The eggs hatch into larvae, which float in the sea for about 87 days before settling on the sand of the ocean floor. The larvae then undergo metamorphosis and change into young sea stars.
The Common Starfish lives for 7-8 years.
Location of photographs: Aquarium de Paris-Cinéaqua, France and Sea Life London Aquarium, England
Photographer: Martina Nicolls
Martina Nicolls: SIMILAR BUT DIFFERENT IN THE ANIMAL KINGDOM