What is larva 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.

What is the trochophore function?

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.

What is a trochophore larva quizlet?

trochophore. a free-swimming, ciliated larva of many worms and some mollusks. visceral mass. the central section of a mollusk’s body that contains the mollusk’s organs.

What phylum are trochophore larvae?

They are triploblastic, bilaterally symmetrical and segmented Metazoa. Some of the annelids belong to the Lophotrochozoa lineage. Trochophore larva occurs in phylum annelida.

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.

How does a trochophore move through water?

The classic trochophore – a larval form shared with some other lophotrochozoans (e.g., molluscs) – is a top-shaped free-swimmer that moves through the water propelled by characteristic bands of cilia and usually has a sensory apical tuft of cilia (Fig. 2).

What is the difference between trochophore and veliger larvae?

Veliger is the second stage of a larva of certain mollusks such as marine snails and bivalves and a few freshwater bivalves. The veliger is developed from the trochophore larva, which has large ciliated lobes called velum. This velum is developed from the ciliary ring of the prototroch.

Do arthropods have trochophore larvae?

Trochophore larvae are characterized by two bands of cilia around the body. Previously, these were treated together as the Trochozoa, together with the arthropods, which do not produce trochophore larvae, but were considered close relatives of the annelids because they are both segmented.

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.

What is the larva 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.

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What is the evolutionary importance of Trochophore?

Many workers are of the opinion that the Trochophore larva serves as a bridge between radial and bilateral symmetry. They have opined that the bilateral symmetry has evolved from the radial one.

What is Bipinnaria in biology?

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.

Which feature of mollusks is a rasping tongue like organ?

You won’t find a radula anywhere in the human body, but it’s a common anatomical feature among animal species in phylum Mollusca. Biologists describe it as a rasping dental ribbon that replaces the tongue found in mammals. Oysters, clams and other bivalves are the only mollusks that lack this organ.

Do annelids have a lophophore?

The Annelida are worms with thorough segmentation of the body. The phoronids, bryozoans, and brachiopods are all filter-feeders that share a ciliated feeding organ called a lophophore.

What is the visceral mass that every mollusk has?

gastropods. The visceral hump, or visceral mass, of gastropods is always contained within the shell; it generally holds the bulk of the digestive, reproductive, excretory, and respiratory systems. A significant part of the visceral hump consists of the mantle, or pallial, cavity.

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.

Are platyhelminthes sessile?

Why does a sessile animal need a motile larval stage? Phylum Platyhelminthes – flatworms, flukes and tapeworms; 18,500 sp. … Because they are so flat, diffusion is sufficient for respiration, and flatworms lack respiratory and circulatory systems.

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 juvenile mollusks called?

Like many invertebrates, the mollusk life cycle includes one or more juvenile or larval stages that are very different from the adult form of the animal. Both mollusks and annelids develop through a larval stage called a trochophore larva.

Which class of mollusks contain octopi and squids?

Cephalopods are a group of molluscs that include the pearly chambered Nautilus, squids, and the octopus. They can be divided into three categories: the Nautiloidea (chambered Nautilus), the Ammonoidea (the extinct ammonites), and the Dibranchiata (squids, the extinct belemnites, and octopuses).

Do Veliger larvae have shells?

Veligers are planktonic larvae of many bivalve and gastropod molluscs characterized by a shell, foot, and velum (a lobed, ciliated structure used for swimming and feeding). The velum is derived from the prototroch – a pre-oral ciliated band in the trochophore larva.

What is the larval stage of echinoderms?

Echinoderms show a complicated metamorphosis in the course of development. Their larva is strikingly bilaterally symmetrical whereas the adult shows radial symmetry. Larva swims with the help of ciliated bands , which may be complicated by a number of short or long slender projections or arms from the body wall.

Which is the largest mollusk class?

Gastropods are by far the largest class of molluscs, comprising over 80% of all molluscs.

For what purpose is a Radula used?

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).

Which of the following annelida class has Trochophore larva?

Trochophore larvae are most commonly found in Mollusca and Annelida. So the correct option is A) Annelida and Mollusca.

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

The nauplius is the most primitive crustacean larval type found in extant crustaceans, and the earliest free-swimming phase in crustacean development.

What is the meaning of Veliger?

veliger. / (ˈvɛlɪdʒə) / noun. the free-swimming larva of many molluscs, having a rudimentary shell and a ciliated velum used for feeding and locomotion.

Are crustaceans Ecdysozoans?

Ecdysozoa (/ˌɛkdɪsoʊˈzoʊə/) is a group of protostome animals, including Arthropoda (insects, chelicerata, crustaceans, and myriapods), Nematoda, and several smaller phyla. … The group is also supported by morphological characters, and includes all animals that grow by ecdysis, moulting their exoskeleton.

Are octopus Lophotrochozoans?

The Trochozoa contain many worm-like forms, including the segmented worms (Phylum Annelida) but it also includes the Mollusca (snails, squid, octopods, clams, etc).

What kind of larva do crustaceans have?

The first larval stage for crabs, lobsters, shrimp, barnacles, copepods, and some other crustaceans is called a nauplius. The nauplii of different species all look alike so they are hard to tell apart. These larvae live in the water column as part of the zooplankton.

When present a crustacean larva is called?

organization and function. In animal development: The larval stage. In crustaceans the larva, called nauplius, does not differ substantially in mode of life or means of locomotion from the adult but has fewer appendages than the adult. A typical crustacean nauplius has three pairs of legs and an unpaired simple eye.