What is the difference between cnidarians and flatworms?

What is the difference between cnidarians and flatworms?

Flatworms are more complex than cnidarians. Cnidarians have two layers of cells, the ectoderm and the endoderm; flatworms have a middle layer called the mesoderm between the other two layers (Fig. 3.16). The cells of the ectoderm and endoderm are also more organized than similar cells of cnidarians.

What are the characteristics of cnidarians?

What are the Characteristics of Cnidarians?

• They are characterized by the presence of stinging cells called Cnidoblast and a cavity called coelenterates, justifying the name Cnidaria or Coelenterata.
• They are exclusively aquatic and marine.
• They are radially symmetrical and diploblastic animals.

Do cnidarians have brains?

Cnidaria do not have a brain or groups of nerve cells (“ganglia”). The nervous system is a decentralized network (‘nerve net’), with one or two nets present. They do not have a head, but they have a mouth, surrounded by a crown of tentacles. The tentacles are covered with stinging cells (nematocysts).

Do flatworms have a coelom?

Flatworms are bilaterally symmetrical with a defined head and tail region and a centralized nervous system containing a brain and nerve cords. They have no circulatory system or body cavity (coelom), but they do have an excretory and digestive system.

What do all cnidarians have in common?

Cnidarians share several basic characteristics. All Cnidaria are aquatic, mostly marine, organisms. They all have tentacles with stinging cells called nematocysts that they use to capture food. Cnidarians only have two body layers, the ectoderm and endoderm, separated by a jelly-like layer called the mesoglea.

What do cnidarians have in common?

What’s the difference between a nematode and an annelid?

Summary – Nematodes vs Annelids. Phylum Nematoda and Annelida are two phyla of kingdom Animalia. Nematodes are cylindrical and roundworms with un-segmented bodies. Annelids are segmented worms. They possess a true coelom, unlike nematodes which have a pseudocoelom. This is the difference between Nematodes and Annelids.

Which is more advanced echinoderm or phylum Annelida?

Phylum annelid includes bilaterally symmetrical segmented worms while phylum Echinodermata includes radially symmetrical marine organisms. Echinoderms are more advanced than annelids. Moreover, they have a complex body structure, and they are very closer to chordates.

What kind of body does the phylum Annelida have?

Phylum Annelida consists of segmented worms with true coeloms. These organisms are triploblastic and show bilateral symmetry. Annelids have tube-like bodies with simple organ systems, including straight alimentary canal, nephridia, closed circulatory system, double ventral nerve cord.

How many species of annelids are there in the world?

Annelida refers to a phylum of kingdom Animalia, consisting of segmented worms with elongated body forms. About 9000 species of annelids have been identified so far. Most annelids are aquatic, and some are terrestrial. Annelids are free-living animals with bilateral symmetry.