What distinguish Nemertines from platyhelminthes?

What distinguish Nemertines from platyhelminthes?

Nemertines, unlike flatworms (Phylum Platyhelminthes), have a blood vascular system through which contractile vessels and body muscle contractions pump blood. Unidirectional valves and heart are lacking. The heme-containing blood cells in a few species may carry oxygen.

What are the characteristics of Nemertea?

Characteristics of Nemertea: Bilaterally symmetrical and dorsoventrally flattened. Body has more than two layers of cells with tissues and organs. Body has a through gut with a mouth and anus. Body has no body cavity.

What does Nemertea mean?

ribbon worms
Nemertea is a phylum of animals also known as ribbon worms or proboscis worms. Most ribbon worms are very slim, usually only a few millimeters wide, although a few have relatively short but wide bodies. Many have patterns of yellow, orange, red and green coloration.

What do nemerteans do?

Nemertea play an important ecological role in food chains. Most species are carnivorous, consuming invertebrates such as annelids, mollusks, crustaceans, jellyfish, and so forth, but also fish and fish eggs. They can be voracious predators, eating almost anything and animals much larger than themselves.

How can you distinguish the nematodes from the Platyhelminthes for the Platyhelminthes How can you distinguish the class trematoda worms from the class cestoda worms?

The main difference between Platyhelminthes and Nematoda is that Platyhelminthes consists of flatworms with a thin, dorso-ventrally flattened body whereas Nematoda consists of a cylindrical body, which is tapered to fine ends at each end. Tapeworms, Turbellaria, Trematoda, and Monogenea examples of Platyhelminthes.

How do you distinguish between the Platyhelminthes and nematodes?

The phylum Platyhelminthes contains flatworms, whereas nematodes are roundworms. Platyhelminthes are acoelomate, whereas nematodes have pseudocoelom. Platyhelminthes are hermaphrodites or monoecious, whereas nematodes are dioecious, i.e. sexes are separate.

What order is Nemertea?

Taxonomy of the Nemertea was formerly straight forward, as there are only two classes: Enopla and Anopla. The Class Enopla includes two orders (Bdellonemertea and Hoplonemertea) with about 650 species that have a proboscis usually armed with stylets and a mouth that opens in front of the brain.

What does Rhynchocoel mean?

Definition of rhynchocoel : a tubular cavity that holds the introverted proboscis of a nemertean worm and is sometimes considered homologous with the coelom.

Is the ribbon worm real?

Ribbon worms, or nemerteans, are a group of very unusual worms related to mollusks and annelids. Most ribbon worms live in the ocean, and some can grow to over 100 feet long, but are usually much less than an inch wide. Some species live on land or in freshwater. Unlike annelids, ribbon worms are not segmented.

What is the difference between trematoda and Cestoda?

Cestodes are tape-like and segmented in shape, have a head with suckers and possibly hooks, and lack a digestive tract. Trematodes are leaf-like and unsegmented, lack hooks entirely, and have an incomplete digestive tract. Generally, cestodes require two hosts and trematodes need three to complete their life cycles.

How can you distinguish the nematodes from the Platyhelminthes?

The main difference between Platyhelminthes and Nematoda is that Platyhelminthes consists of flatworms with a thin, dorso-ventrally flattened body whereas Nematoda consists of a cylindrical body, which is tapered to fine ends at each end.

Which morphological features differentiate the members of the phylum Annelida from nematodes and Platyhelminthes?

1 Answer. Platyhelminthes are worms with flat bodies (flatworms), nematodes are worms with cylindrical but not segmented bodies (roundworms). Annelids are cylindrical worms with segmented bodies (they are metameric).

What is the Rhynchocoel?

What is trematode and cestode?

INTRODUCTION. Cestodes (tapeworms) and Trematodes (flukes) are two Classes of the Phylum Platyhelminthes. Tapeworms live in the intestines of vertebrates and their larval forms occur in the flesh of animals on which these vertebrates feed.

What’s the difference between Trematoda and Monogenea?

Trematoda, or flukes, are obligate parasitic flatworms that cannot survive without a host. Most flatworms in the class Trematoda have a complex life cycle that involves two or more hosts. Monogenea are ecto-parasites that have only one host per lifetime.

What are the specific characteristics of phylum Annelida which can distinguish from phylum Nematoda?

The main difference between Nematoda and Annelida is that Nematoda has a cylindrical body with tapered ends whereas Annelida has a cylindrical body, which is segmented. Therefore, Nematoda is called roundworms while Annelida is called segmented worms.