How do sponges and cnidarians differ from flatworms and roundworms?

Key Concept. Porifera (sponges) have specialized cells and an endoskeleton but lack true tissues and body symmetry. Platyhelminthes (flatworms) have a mesoderm cell layer, simple organ systems, cephalization, and bilateral symmetry. Nematoda (roundworms) have a pseudocoelom and hydrostatic skeleton.

Are sponges free living or parasitic?

No matter where sponges live, they are mainly sessile organisms. Because most adult sponges are sessile, they can’t travel in search of food.

Which aquatic organisms includes worms and sponges?

Corals, sponges, and worms are common words to our ears, but scientists would call them cnidarians, poriferans, and annelids. They each have their own phylum and each phylum is extremely diverse. One thing they all have in common is that they are ancient and simple biological organisms.

How do sponges and cnidarians protect themselves?

While some creatures such as sponges solve the dilemma of limited mobility by filtering the water for nutrients, cnidarians overcome the problem by deploying fast-acting neurotoxins through their stinging cells. These toxins can immobilize many prey and repel many predators upon contact.

What are 4 ways flatworms and roundworms are different?

Flatworms Roundworms
Flatworms generally live in bodies of water. Roundworm species can live either on water or in soil.
Flatworms are acoelomate, which means they do not have a body cavity. Roundworms are psuedocoelomate, which means they have a body cavity between their mesoderm and endoderm layers.

Do sponges have parasites?

Some organisms that live on (called epibionts) and in (called endobionts) sponges act as parasites. Cyclopoid copepods are the most important parasites of marine sponges; in fact, some genera of these crustaceans have become modified as a consequence of their parasitic existence.

What are the three main phyla of worms?

Worms: Phyla Platyhelmintes, Nematoda, and Annelida.

What is the difference between sponges and cnidarians?

These organisms show a simple organization. Sponges have multiple cell types that are geared toward executing various metabolic functions. Cnidarians have outer and inner tissue layers sandwiching a noncellular mesoglea. Cnidarians possess a well-formed digestive system and carry out extracellular digestion.

Do sponges have polyps?

Sponges aren’t symmetrical, though, and sponges have no tentacles or stinging cells. They also don’t have a mouth.) There are two body types for cnidarians: the polyp and the medusa. The polyp is shaped like a tube and is generally sessile.

What are two differences between flatworms and roundworms?

Hint: The flatworms belong to the phylum Platyhelminthes and around 80% of flatworms are parasitic in nature….What is the difference between flatworms and roundworms?

Flatworms Roundworms
They have a thin, dorsoventrally flattened body, so called flatworms. They have a long cylindrical body, vermiform, unsegmented with no lateral appendages.

What do flatworms look like?

Flatworms have flat, symmetrical, leaf-shaped bodies that grow to a size smaller than a quarter. The oyster flatworm is cream-colored with short tentacles on its sides and has eyespots in two rows along its head.