What are two functions of the cilia in a trochophore?

The cilia on a trochophore are moved rapidly in order to create a water eddy, thus controlling the direction of their movement. List the main parts in the basic body plan of a mollusk.

What are the two functions of the cilia found on the trochophore larva?

A trochophore (/ˈtroʊkəˌfɔːr, ˈtrɒ-, -koʊ-/, also spelled trocophore) is a type of free-swimming planktonic marine larva with several bands of cilia. By moving their cilia rapidly, they make a water eddy, to control their movement, and to bring their food closer, to capture it more easily.

Why are cilia such important structures on trochophore larvae?

Trochophores are spherical or pear-shaped and are girdled by a ring of cilia (minute hairlike structures), the prototroch, that enables them to swim. … Above the prototroch is a sensory plate, an apical tuft of cilia, and an ocellus (simple eye).

How does a trochophore move through water?

In the TROCHOPHORE stage, hair-like structures called “cilia” develop allowing it to move through the water column. Next, during the D-HINGE VELIGER stage, two shells (or “bi-valves”) and the “velum”— an organ for movement and eating—develop.

What do you mean by trochophore?

Definition of trochophore

: a free-swimming ciliate larva occurring in several invertebrate groups (such as the polychaete worms and mollusks)

What are the functions of the cilia on the free swimming trochophore?

The cilia on a trochophore are moved rapidly in order to create a water eddy, thus controlling the direction of their movement. List the main parts in the basic body plan of a mollusk.

What is the significance of trochophore larva?

Trochophore larva has a prominent status in the evolutionary context. Studies are suggestive of the Trochophore larva as a bridge between radial and bilateral symmetry. The larval form shows similarities with many invertebrate groups.

What is the evolutionary importance of trochophore?

As a link between the gastrula and adult-like stages (the veliger in mollusks and the nectochaete in annelids), the trochophore may be an important stage determining the development of the adult body plan.

Which of the following phylum have trochophore larva?

Trochophore larva occurs in phylum annelida.

Do cnidarians have trochophore larvae?

These clades are upheld when RNA sequences are compared. Trochophore larvae are characterized by two bands of cilia around the body. The lophotrochozoans are triploblastic and possess an embryonic mesoderm sandwiched between the ectoderm and endoderm found in the diploblastic cnidarians.

What is trochophore 11?

Trochophores are spherical or pear-shaped and are girdled by a ring of cilia the prototroch, that enables them to swim. In some mollusks (such as gastropods and bivalves), the trochophore develops into a second stage, the veliger, before metamorphosing to an adult form. Hence, option A is the correct answer.

Do echinoderms have trochophore larvae?

D. Trochophore. Hint: Radial symmetry organisms known as echinoderms that have endoskeleton which is observed in the spine and calcareous. There are numerous stages in which larvae of the echinoderms pass.

Do earthworms have a trochophore larva?

They share a distant common ancestor with the annelid worms, an evolutionary heritage suggested by their larval form, called a trochophore larva, found in all molluscs and in certain marine annelids called polychaete worms.

What is the first and most common free-swimming larval stage of many crustacea?

In terms of sheer numbers, the crustacean nauplius (Figures 17.1A, 17.3, 17.4) has been called “the most abundant type of multicellular animal on earth” (Fryer, 1987). The nauplius is the most primitive crustacean larval type found in extant crustaceans, and the earliest free-swimming phase in crustacean development.

Does cephalopod have trochophore stage?

All conchiferans except cephalopods also possess a similar topological arrangement of cerebral, pedal, pleural and buccal ganglia (the latter have been lost in Bivalvia) and a trochophore-like larva is present in all molluscs except for the cephalopods that exhibit direct development (the life cycle of monoplacophorans …

Do arthropods have trochophore larvae?

Until very recently, the Arthropoda (insects &amp, 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.

Is porifera a trochophore?

Invertebrates- are animals that lack a backbone. They account for 95% of known animal species. Lophotrochozoan- have a lophophore (a crown of cilia that surrounds the mouth) or a trochophore (larvae that have cilia around their middle). … Porifera- Sponges are basal animals that lack true tissues.

Do Polychaetes have trochophore larva?

The Larva of planktonic Annelids are known as trocophore, which are translucent, motile zooplankton characteristic of the class Polychaeta, as well as most Mollusk species.

What is the difference in the way aquatic and terrestrial mollusks carry out gas exchange?

Terrestrial mollusks exchange gases with the surrounding air. This occurs across the lining of the mantle cavity. Aquatic mollusks “breathe” under water with gills.

What is the larval form of Arthropoda?

This larval stage, called a nauplius, is found in barnacles, copepods, penaeid shrimps, and ostracods. It swims by using its jointed appendages that are moved by muscle contraction. These larvae have a nauplier eye, made up of photoreceptor cells that are thought to give rise to the photoreceptors in some adult forms.

What is the function of Telotroch?

Telotroch is the free-swimming stage of members of the order Sessilida. Sessilida are ciliates of the subclass Peritrichia. A sessile individual can turn into a motile one to migrate to a better place.

What is the larval stage of echinoderms?

Class Holothuroidea demonstrate two larval stages, namely, auricularia and doliolaria larvae. ➢ Auricularia larva has striking resemblance with bipinnaria of Asteroidea as it also possesses 4 or 5 pairs of ciliated arms for swimming and has a well- developed mouth, gut and anus.

Are trochophore larvae homologous?

Certain annelid worms have a larval stage called a trochophore larva, which is essentially identical to the trochophore larval stage of the molluscs. This suggests that these two groups share a common ancestry. … Homologous structures are structures that are derived from a common ancestor.

What is the meaning of veliger?

Definition of veliger

: a larval mollusk in the stage when it has developed the velum.

What is Glochidium larva?

The glochidium (plural glochidia) is a microscopic larval stage of some freshwater mussels, aquatic bivalve mollusks in the families Unionidae and Margaritiferidae, the river mussels and European freshwater pearl mussels.

Which one of the following is a Lophotrochozoan?

Lophotrochozoa is a monophyletic group of animals that includes annelids, molluscs, bryozoans, brachiopods, platyhelminthes, and other animals that descended from the common ancestor of these organisms. Lophotrochozoa is one of the three major clades that comprise bilateral animals, or Bilateria.

Which of the following is molluscan larva?

Explanation: Veliger, larva typical of certain mollusks such as marine snails and bivalves and a few freshwater bivalves. The veliger develops from the trochophore (q.v.) larva and has large, ciliated lobes (velum).

What kind of larvae do molluscs have?

A veliger is the planktonic larva of many kinds of sea snails and freshwater snails, as well as most bivalve molluscs (clams) and tusk shells.

Who has a trochophore?

Both the echiurans and the sipunculans have a trochophore. In the echiurans, metamorphosis follows a relatively brief trochophore stage. One unusual feature of the bonellid echiurans is that the larvae have indeterminate sex.

Which of the following are characteristics of members of the Cnidaria phylum?

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. Most Cnidarians have radial symmetry.

Do cnidarians have radial cleavage?

The symmetry properties of bilaterally symmetrical larval and adult metazoans are generally set up during the cleavage period while most “radially” symmetrical cnidarians do not display a stereotyped cleavage program.

Do Cnidaria have Trochophores?

These clades are upheld when RNA sequences are compared. Trochophore larvae are characterized by two bands of cilia around the body. The lophotrochozoans are triploblastic and possess an embryonic mesoderm sandwiched between the ectoderm and endoderm found in the diploblastic cnidarians.

What is the ciliated larval stage of mollusks called?

veliger, larva typical of certain mollusks such as marine snails and bivalves and a few freshwater bivalves. The veliger develops from the trochophore (q.v.) larva and has large, ciliated lobes (velum).

How have cephalopods adapted their muscular foot?

Cephalopods are active predators that can move very quickly, but they do not generally use their foot for movement. Instead, they contract muscles surrounding the mantle cavity to thrust water out of the cavity. This jet-propulsion mechanism is responsible for their rapid movement.

What is a starfish larva called?

From Wikipedia, the free encyclopedia. A bipinnaria is the first stage in the larval development of most starfish, and is usually followed by a brachiolaria stage. Movement and feeding is accomplished by the bands of cilia.

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.

Where do we find water vascular system?

Water vascular system is found in echinoderms. Echinoderms are marine invertebrates that include the sea urchins, starfish, brittle stars, and sea cucumbers. Water vascular system is a division of the coelom and most distinctive feature of echinoderms. It is a system of canals and appendages of body wall.

Why are cilia such important structures on trochophore larvae?

Trochophores are spherical or pear-shaped and are girdled by a ring of cilia (minute hairlike structures), the prototroch, that enables them to swim. … Above the prototroch is a sensory plate, an apical tuft of cilia, and an ocellus (simple eye).

Are leeches mollusks?

Mollusks are invertebrates such as snails, scallops, and squids. They have a hard outer shell. … Different classes of mollusks have different ways of obtaining food. Annelids are segmented worms such as earthworms and leeches.

How do annelids eat?

Burrowing annelids, like the earthworm, play an important role in helping organic matter decompose. Earthworms eat dead plants and animals. When they eat, they also take in soil and tiny pebbles. Earthworms take in nutrients from microorganisms in the material they ingest.