Sponges, also known as poriferans, primarily reproduce through two main methods:
1. Sexual Reproduction
- Internal Fertilization: Some species have separate sexes, and internal fertilization occurs when sperm released by male sponges are captured by specialized cells in female sponges. Fertilization then occurs within the female sponge, leading to the development of larvae.
- External Fertilization: In other species, sponges release sperm and eggs into the water, where external fertilization takes place. Fertilized eggs develop into larvae, which eventually settle and grow into new sponges.
2. Asexual Reproduction
- Budding: Some sponges reproduce asexually through budding, where small outgrowths, or buds, develop on the body of the sponge. These buds then detach and grow into new, genetically identical sponges.
- Gemmosis: Another asexual method involves the formation of specialized reproductive structures called gemmules. These are clusters of cells surrounded by a protective coat. During adverse conditions, such as when environmental conditions are harsh, these gemmules can withstand desiccation or freezing. When conditions become favorable again, gemmules can release cells that develop into new sponges.
These different methods of reproduction in sponges provide them with both flexibility and resilience in various environmental conditions, ensuring their survival and propagation in diverse habitats.