Sponges are individual animals not colonial like corals.
Sponges are filter feeders. They create a current to draw water in through their tissues and filter out any small particles of food.
No one is really sure if these sponges have a defined breeding season as such because they live in such deep water. Other sponge species are influenced by the seasons and the phases of the moon. Hexactinellid sponges are viviparous. Eggs develop into larvae within the sponge and then these motile larvae are released into the water current. The larvae have a band of hairs (cilia) which enable them to propel themselves through the water. Laboratory studies of another species of glass sponge have shown that the while the larvae are capable of swimming for several days in fact they tend to settle after only about 12 hours before developing into juvenile forms of the adult.