How do animal sponges reproduce sexually?

Most sponges are hermaphroditic, meaning individuals can produce both eggs and sperm, though they often do so at different times to avoid self-fertilization.12

The process of sexual reproduction in sponges is unique:

• Fertilization: Sperm are released into the water and carried by currents to another sponge. They are captured by specialized flagellated cells called choanocytes.32
• Transport: The choanocyte transforms into a carrier cell, which delivers the sperm to an egg located within the sponge's interior.32
• Development: Most sponges are viviparous, meaning they release living larvae through the excurrent water system. A few species are oviparous and lay eggs.3
• Metamorphosis: After a brief free-swimming period, the larva settles on a suitable surface and undergoes metamorphosis to become a young adult sponge.32

The timing of sexual maturation is often influenced by water temperature, with many species in temperate regions reproducing between spring and autumn.3