Characteristics of Porifera

Characteristics

• Simple, multicellular animals
• Porous body (hence the name "Porifera") with a network of canals and chambers
• No true tissues or organs
• No nervous system, muscles, or sense organs
• Feed using specialized cells called choanocytes

Body Structure

• Asymmetrical body shape
• Three main layers: ectoderm, mesohyl, and endoderm
• Mesohyl is a gelatinous layer that contains skeletal elements and amoeboid cells

Skeletal Elements

• Spicules (small, needle-like structures) made of calcium carbonate or silica
• Spongin (a protein-based skeletal material) found in some species

Feeding and Digestion

• Filter feeders: use choanocytes to capture small particles and bacteria from the water
• Amoeboid cells help to digest food particles

Reproduction

• Asexual reproduction: budding or fragmentation
• Sexual reproduction: release of sperm and eggs into the water column
• Fertilization occurs externally, resulting in a larva that settles and develops into a new individual

Classification

• Three main classes: Calcarea, Hexactinellida, and Demospongiae
• Over 8,000 described species, ranging from 1-2 mm to 2 meters in diameter

Importance

• Play a crucial role in filtering and purifying water
• Provide habitat for numerous other species
• Some species have been used as a source of medicinal compounds and biomaterials

Characteristics of Sponges

• Possess a porous body with a network of canals and chambers
• Lacking true tissues and organs
• Devoid of a nervous system, muscles, and sense organs
• Rely on specialized choanocytes for feeding

Body Structure of Sponges

• Feature an asymmetrical body shape
• Comprised of three main layers: outer ectoderm, gelatinous mesohyl, and inner endoderm
• Mesohyl contains skeletal elements and amoeboid cells

Skeletal Elements in Sponges

• Spicules: small, needle-like structures composed of calcium carbonate or silica
• Spongin: a protein-based skeletal material found in some species

Feeding and Digestion in Sponges

• Function as filter feeders, capturing small particles and bacteria using choanocytes
• Amoeboid cells aid in digestion of food particles

Reproduction in Sponges

• Undergo asexual reproduction through budding or fragmentation
• Engage in sexual reproduction via release of sperm and eggs into the water column
• External fertilization results in larval formation, which settles and develops into a new individual

Classification of Sponges

• Divided into three main classes: Calcarea, Hexactinellida, and Demospongiae
• Encompass over 8,000 described species, ranging from 1-2 mm to 2 meters in diameter

Importance of Sponges

• Play a crucial role in water filtration and purification
• Provide habitat for numerous other species
• Certain species have been utilized as sources of medicinal compounds and biomaterials