Asterisk: The Future of Telephony, 2nd Edition

Colophon

The animals on the cover of Asterisk: The Future of Telephony are starfish. Starfish are classified as Asteroidea. They are a group of echinoderms, spiny-skinned invertebrates found only in the sea. Most starfish have fivefold symmetry (arms or rays in multiples of five), though some species can have four or nine arms. But all starfish are radially symmetrical: they have arms or rays branching out from a central body disc. There are over 1,500 species of starfish.

Starfish live on the floor of the sea and in tidal pools, clinging to rocks and moving (slowly) using a water-based vascular system to manipulate their hundreds of tiny, tube-like legs, called podia. A small bulb or ampulla at the top of the tube contracts, expelling water and expanding the starfish’s leg. The ampulla relaxes, and the leg retracts. Starfish use muscles to bend their legs, but it is the flow of water pressure that keeps the feet moving. At the tip of each leg, starfish have suction cups that allow them to pry open clam, oyster, or mussel shells. Many starfish can push their stomachs out through their mouths in order to digest their prey in its shell. Starfish are carnivores; they eat coral, fish, and snails, as well as bivalves.

Starfish can flex and rearrange their arms to fit into small places as they move over the ocean floor. At the end of each arm, they have eyespots, primitive sensors that detect light and help the starfish determine direction. Starfish also have the ability to regenerate a ...