Keith Ball (July)
The Common starfish (Asterias rubens) can vary in colour quite a lot, this one was a particularly bright orange but they can be found from red to yellowish-brown and more rarely violet.
Starfish have a bizarre eating habit: they feed by forcing their membranous stomachs out through their mouths and secreting enzymes that digest the food, which is transported to the gut by special hair-like cilia. Starfish are active carnivores and also scavenge. They prey on bivalve molluscs by forcing their shells open with their tube-feet. The stomach everts over or into the prey liquifying it so that it can be easily digested.
The common starfish is normally 10-30cm, they can grow to a maximum diameter 50cm.
Starfish are also capable of regenerating arms which have broken off, and in some cases a new starfish can generate from a severed arm.