Osculum

Definition

An osculum is a large opening in a sponge through which water exits after passing through the sponge's body. It plays a critical role in the sponge's filter-feeding system.

5 Must Know Facts For Your Next Test

1. The osculum is usually located at the top of the sponge.
2. It serves as an exit point for water that has been filtered for nutrients by the sponge.
3. Sponges can have one or multiple oscula depending on their size and species.
4. The structure of the osculum can vary among different types of sponges, influencing water flow efficiency.
5. The function of the osculum is vital for maintaining the internal water circulation necessary for feeding and respiration.

Review Questions

• What is the primary function of the osculum in a sponge?
• Where is the osculum typically located in a sponge?
• How does the number and structure of oscula affect a sponge’s ability to filter water?

Related terms

Porocytes: Cells that form pores allowing water to enter into a sponge.

Choanocytes: Specialized cells within sponges that trap and digest food particles.

Spongocoel: The central cavity within a sponge where filtered water collects before exiting through the osculum.