either side of the dorsal stalk. They develop into zooids not unlike the nurse, each attached to its dorsal stalk with its own dorsal stalk. These zooids differ from the individual independent adult; their intake siphons are so much wider than the rear that the individual zooid is spoon-shaped rather than barrel-shaped. The spoon-shaped zooids supply food for the whole colony via a common blood circulation along two blood-filled sinuses that extend from the nurse along the whole length of the dorsal stalk. As this first generation grows, the nurse's feeding role is gradually diminished, and at the point where the colony's nutrition is supplied by the stalk zooids the nurse loses most of its organs, becoming a purely generative and propulsive agent, dragging its huge grape-like stalk behind it. As the dorsal stalk grows and more zooids grow along its sides, the phorocytes begin to grow a second batch of buds in two more rows between the first two, on the dorsal side of the stalk. These grow into asexual zooids that are smaller, are barrel-shaped like the nurse, and are attached to the nurse's stalk with their ventral stalks. They do not have a dorsal stalk themselves. Because of their later function, members of this generation are called phorozooids, which means "carrier zooids". Finally, when the two phorozooid rows on the nurse's stalk are filled up and the first phorozooids grow big enough, the phorocytes begin to plant subsequent buds on the stalks of phorozooids, which are still attached to the main colony at this point. Only this third batch of buds eventually grows into gonozooids - the sexual generation. As phorozooids mature, their stalks detach from the nurse's stalk, and they swim away on their own, carrying budding gonozooids on their own stalks. The nurse and its battery of feeding zooids goes on until all carriers leave, and then the whole colony dies off. The carriers go on as long as it is required for the gonozooids on their stalks to grow and detach, and then they die off too. Gonozooids detached from the phorozooid swim free, mate, and produce fertilized eggs - from which spring the next generation of asexual zooid "factories", and the cycle repeats. The total number of zooids produced by a single nurse colony can reach tens of thousands - explosive growth unusual in the animal kingdom. Natural enemies The gelatinous doliolid Dolioletta