How Long:
Some ribbon worms can grow to be quite long. One type called a bootlace worm is one of the largest known invetebrates. It can stretch to 30m long (100ft). That`s as long as a Boeing 737 aeroplane. Ribbon worms have amazing power of contraction. Some species can extend to more than 10m (32ft) in length and then contract to just a few cms. These meat eaters feed mostly on other worms such as flat worms and round worms but also eat crustaceans such as crabs and shrimps and even small fishes.