What is the key defining characteristic of the Ecdysozoans?

What is the key defining characteristic of the Ecdysozoans?

Characteristics. The most notable characteristic shared by ecdysozoans is a three-layered cuticle (four in Tardigrada) composed of organic material, which is periodically molted as the animal grows. This process of molting is called ecdysis, and gives the group its name.

What is the main difference between Lophotrochozoa and ecdysozoa?

What is the difference between Lophotrochozoa and Ecdysozoa? Ecdysozoans have the ability to shed their exoskeleton several times throughout their life span, whereas lophotrochozoan are the animals who possess a trochophore larvae and a feeding structure called lophophore.

What are Lophotrochozoans and Ecdysozoans?

Protostome Evolution 1. The Lophotrochozoa – which includes the segmented worms, molluscs, lophophorates and several smaller phyla. 2. The Ecdysozoa – which includes the arthropods and several other phyla that periodically molt.

What are the characteristics of Deuterostomes?

What is characteristic of deuterostomes

• Spiral cleavage, blastopore becoming mouth.
• Radial cleavage, blastopore becoming anus.
• Spiral cleavage, blastopore becoming anus.
• Radial cleavage, blastopore becoming mouth.

Do platyhelminthes have a Lophophore?

Phylum Platyhelminthes. The flatworms possess neither a lophophore nor trochophore larvae, although the larvae of one group of flatworms, the Polycladida (named after its many-branched digestive tract), are considered to be homologous to trochophore larvae.

What are five characteristics of phylum platyhelminthes?

Some of the characteristics that distinguish the organisms belonging to phylum Platyhelminthes from others are:

• Presence of flame cells.
• Ladder-like nervous system.
• Presence of parenchyma in the body cavity.
• Self-fertilization.

Is Mollusca a Lophophore?

Phylum Mollusca: Snails, clams, squids, etc., described below. Four phyla (Entoprocta, Phoronida, Bryozoa, Brachiopoda) characterized by a ciliated feeding organ called a lophophore.

What’s a Trochophore?

Trochophore, also called trochosphere, small, translucent, free-swimming larva characteristic of marine annelids and most groups of mollusks. Trochophores are spherical or pear-shaped and are girdled by a ring of cilia (minute hairlike structures), the prototroch, that enables them to swim.

Who uses a radula?

Within the gastropods, the radula is used in feeding by both herbivorous and carnivorous snails and slugs. The arrangement of teeth (denticles) on the radular ribbon varies considerably from one group to another.

Are arthropods Trochophore?

Also, do arthropods have Trochophore larvae? Until very recently, the Arthropoda (insects & crustaceans) were considered possible close relatives of the Annelida, based on the fact that both groups are segmented, but no arthropod has a trochophore larva and no molecular studies support a close relationship.

What is the purpose of the radula?

The radula, part of the odontophore, may be protruded, and it is used in drilling holes in prey or in rasping food particles from a surface. It is supported by a cartilage-like mass (the odontophore) and is covered with rows of many small teeth (denticles).

What are the three major classes of mollusks?

The three major groups of mollusks are gastropods, bivalves, and cephalopods (SEF ul o pods). The largest group is the gastropods. These are mollusks like snails and slugs that have just one shell or no shell at all. Gastropods creep along on their broad foot.

What organisms are gastropods?

The class Gastropoda includes snails, slugs, limpets, and sea hares; the common name for all of these animals is “gastropods. Gastropods are animals in the Class Gastropoda – the group of organisms that includes snails, slugs, limpets and sea hares.

Why are gastropods so successful?

Gastropods are well-known animals which have been associated with humans since the dawn of civilization. Their bodies were gathered for food and their shells were used as tools, ornaments, and later as money. Their widespread occurrence is clear evidence of their successful adaptation to different environments.

What do all gastropods have in common?

Gastropods have a muscular foot which is used for “creeping” locomotion in most species. In some, it is modified for swimming or burrowing. Most gastropods have a well-developed head that includes eyes, 1-2 pairs of tentacles, and a concentration of nervous tissue (ganglion).

Where are gastropods found?

Gastropods live in every conceivable habitat on Earth. They occupy all marine habitats ranging from the deepest ocean basins to the supralittoral, as well as freshwater habitats, and other inland aquatic habitats including salt lakes.

Do snails kill people?

Freshwater snails: 20,000+ deaths a year The freshwater snail carries parasitic worms that infect people with a disease called schistosomiasis that can cause intense abdominal pain and blood in the stool or urine, depending on the area that’s affected.

Can snails bite you?

So, do snails bite? Yes, snails can bite with their thousands of teeth but due to the lack of force, it won’t hurt at all. Instead, it feels like a tiny brush scraping your finger. Only a few wild snails are capable of biting one’s skin painfully.