What is the meaning of Nemertea?

: a class or other category of Platyhelminthes comprising soft-bodied often brightly colored unsegmented acoelomate worms that have an anterior mouth and posterior anus, a long eversible proboscis, and a definite circulatory system, are typically elongate and contractile, and are usually marine and littoral and burrow …

Is Nemertea parasitic?

ribbon worm, also called bootlace worm, proboscis worm, nemertine, or nemertean, any member of the invertebrate phylum Nemertea (sometimes called Nemertinea, or Rhynchocoela), which includes mainly free-living forms but also a few parasites of crustaceans, mollusks, and sea squirts.

Is Nemertea bilateral?

Nemertean worms are ribbon-shaped, bilaterally symmetrical worms that are usually less than twenty centimeters (7.9 inches) long, although a few reach several meters in length.

Where is the nemertean mouth?

Nemerteans also have dorso-ventral muscles, which flatten the animals, especially in the larger species. Inside the concentric tubes of these layers is mesenchyme, a kind of connective tissue. In pelagic species this tissue is gelatinous and buoyant. The mouth is ventral and a little behind the front of the body.

What is the main characteristic for phylum Nemertea?

Animals in phylum Nemertea show a flattened morphology, that is, they are flat from front to back, like a flattened tube. Nemertea are soft and unsegmented animals (Figure 1). A unique characteristic of this phylum is the presence of a proboscis enclosed in a rhynchocoel.

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.

How do phylum Nemertea reproduce?

Most Nemertea reproduce by sexual reproduction, being either male or female. However some freshwater and terrestrial species are hermaphroditic and can be self fertilising. In a very few species, the eggs are retained within the female and hatch as small copies of the adult to then be released into the world.