Veliger

Larval stage of certain mollusks

The veliger is a larval stage in the development of certain mollusks, particularly within the classes Gastropoda and Bivalvia. This stage follows the trochophore larva and is characterized by the development of a ciliated structure known as the velum, which is used for swimming and feeding.

Development

The veliger stage is a critical phase in the life cycle of many mollusks. During this stage, the larva undergoes significant morphological changes that prepare it for its transition to a juvenile and eventually an adult form. The velum, a distinctive feature of the veliger, is a lobed, ciliated structure that facilitates locomotion and feeding in the planktonic environment.

9-day-old veliger larva of the nudibranch Tritonia diomedea

Morphology

The veliger larva possesses a shell, which is often coiled in gastropods and bivalves. The shell provides protection and is an important feature that distinguishes the veliger from earlier larval stages. The velum is used to capture food particles from the water, and its cilia beat in a coordinated fashion to create water currents that bring food to the larva.

Metamorphosis

As the veliger matures, it undergoes metamorphosis, a process that involves the reorganization of its body structure to form the adult morphology. This includes the development of the foot, the reduction or loss of the velum, and the further development of the shell and other adult structures.

Ecological Role

Veligers play a crucial role in the dispersal of mollusk species. As planktonic larvae, they can be carried by ocean currents over long distances, allowing for the colonization of new habitats. This dispersal capability is essential for the survival and genetic diversity of mollusk populations.

Veliger of Dolabrifera

Examples of Veligers

Nudibranchs

Nudibranchs, a group of soft-bodied, marine gastropod mollusks, often have a veliger stage in their development. The veliger of the nudibranch Tritonia diomedea is an example of this larval form.

Bivalves

Many bivalves, such as clams and oysters, also have a veliger stage. This stage is crucial for their life cycle, as it allows for the wide dispersal of the species in marine environments.

Fiona pinnata veliger

Related Pages

• Trochophore
• Gastropoda
• Bivalvia
• Mollusca

Gallery

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  Fiona pinnata veliger

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  Fiona pinnata veliger

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  Fiona pinnata veliger

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  Fiona pinnata veliger

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  Fiona pinnata veliger

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