Phylum Porifera | Biology for JAMB PDF Download

Phylum Porifera, commonly known as sponges, is a diverse group of organisms within the animal kingdom. Here are some key points about Phylum Porifera, along with common examples:

• Body Structure: Sponges have a unique body organization characterized by a porous and asymmetrical structure. They lack true tissues and organs and are composed of specialized cells that perform specific functions.
• Canal System: Sponges possess a canal system that allows water to flow through their bodies. This system consists of small pores called ostia, which enable water entry, and a larger opening called the osculum, through which water exits.
• Skeleton: Sponges have a simple skeleton made up of microscopic needle-like structures called spicules or a protein matrix called spongin. These provide structural support and protection to the sponge.
• Feeding and Digestion: Sponges are filter feeders, extracting food particles from the water that passes through their bodies. Specialized collar cells called choanocytes create water currents and capture food, which is then digested by amoeboid cells called archaeocytes.
• Reproduction: Sponges can reproduce both sexually and asexually. Asexual reproduction occurs through fragmentation, where a piece of the sponge can grow into a new individual. Sexual reproduction involves the production of eggs and sperm by specialized cells, which are released into the water for fertilization.

Examples: Some common examples of Phylum Porifera include:

• Grantia: Grantia, also known as the "cup sponge," is a marine sponge found in shallow coastal waters. It has a vase-like shape and is often attached to surfaces such as rocks or shells.
• Spongilla: Spongilla, commonly referred to as the "freshwater sponge," inhabits freshwater environments such as lakes, ponds, and slow-moving streams. It forms green or brown encrustations on submerged surfaces.
• Euspongia: Euspongia, also known as the "bath sponge," is a commercially important marine sponge. It is harvested for its natural spongin fibers, which are used in bathing and cleaning products.
• Sycon: Sycon is a marine sponge that features a tubular body with a central cavity lined by choanocytes. It is found in various marine habitats, including coral reefs and rocky shores.

Understanding the characteristics and examples of Phylum Porifera is essential for comprehending the diversity and ecological roles of organisms within the animal kingdom.