What is the difference between Cnidaria and porifera? | Query Point Official

What is the difference between Cnidaria and Porifera?

Cnidaria and Porifera are two different animal phyla in the kingdom Animalia. Both are aquatic invertebrates, but they differ significantly in structure, organization, symmetry, feeding mechanisms, and complexity. Understanding these differences is important for biology students studying invertebrate classification.

What Is Porifera?

Porifera, commonly called sponges, are simple aquatic animals characterized by a porous body and a water‑canal system used for filter feeding. They lack true tissues and organs, and their body organization is at the cellular level.

What Is Cnidaria?

Cnidaria includes animals such as jellyfish, corals, sea anemones, and hydra. Cnidarians show a higher level of organization than Porifera, with true tissues and simple structures like nerve nets and a gastrovascular cavity. They possess specialized stinging cells called cnidocytes used for capturing prey.

Key Differences Between Cnidaria and Porifera

Feature	Cnidaria	Porifera
Body Organization	Tissue level with true tissues (diploblastic)	Cellular level; lacks true tissues
Symmetry	Radial symmetry	Asymmetrical (no true symmetry)
Nervous System	Simple nerve net present	No nervous system
Feeding	Predatory; uses cnidocytes to capture prey	Filter feeding using water currents
Digestion	Gastrovascular cavity (extracellular and intracellular digestion)	Intracellular digestion by specialized cells
Body Forms	Polyp and medusa (motile and sessile)	Sessile throughout life
Reproduction	Both sexual and asexual (budding, external fertilization)	Both sexual and asexual (budding, fragmentation)
Examples	Hydra, jellyfish, corals, sea anemones	Sponges like Sycon, Spongilla

In summary, Porifera are the simplest multicellular animals with no tissues or organs and depend on filter feeding. Cnidarians are more advanced with true tissues, a nervous network, radial symmetry, and specialized cells for hunting and defense.

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FAQs

1. Do Porifera have true tissues?

No. Porifera lack true tissues and organs; their bodies are made up of loosely organized cells.

2. What special cells do Cnidarians have?

Cnidarians possess cnidocytes, which are stinging cells used to capture prey and defend against predators.

3. Can Porifera move?

Adult Porifera are generally sessile (fixed in one place), though their larvae may be motile.

4. What types of symmetry do these phyla exhibit?

Cnidaria exhibit radial symmetry, while Porifera are typically asymmetrical.

5. Do both groups reproduce sexually?

Yes. Both Porifera and Cnidaria can reproduce sexually and asexually through various mechanisms.

Explore more about ANIMAL DIVERSITY in Zoology Notes & MCQs.