Does the larva stage resemble the adult?
Jan 01, 2020 · What is the larval stage of a mollusk? Both mollusks and annelids develop through a larval stage called a trochophore larva. Trochophore larvae are characterized by having a band of cilia that wraps around the body. Click to see full answer.
What are some interesting facts about mollusks?
Feb 13, 2021 · What is the larval stage of the mollusk called? Veliger 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). The velum forms from the ciliary ring (prototroch), a characteristic of the trochophore stage.
What is the larva stage of mollusks and annelids?
Mar 05, 2021 · What is the larval stage of mollusks called? veliger 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). The velum forms from the ciliary ring (prototroch), a characteristic of the trochophore stage.
What animals belong to the phylum Mollusca?
Mar 28, 2020 · 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.
Do molluscs have larvae?
Unlike echinoderms, molluscs do not have a larval body separate from the juvenile/adult body; molluscan larvae have only transient larval traits.
How do mollusks go through larval stages?
Do mollusks go through larval stages? Explain your answer. Yes. They go through trohopore which is a type of free swimming marine larva.
Do molluscs lack a larval stage?
Unlike echinoderms, molluscs do not have a larval body separate from the juvenile/adult body; mollus- can larvae have only transient larval traits.
What is the function of the larval stage?
A larva sometimes functions as a food gatherer—in many species the larval stage occurs at a time when food is abundant—and has a well-developed alimentary system. It stores food so that the transformation to the adult stage can occur. Some larvae function in both dispersion and nutrition.
How does mollusk reproduce?
HOW DO MOLLUSKS REPRODUCE? Mollusks reproduce sexually. Slugs and snails are hermaphrodites (possessing both male and female organs), but they must still mate to fertilize their eggs. Most aquatic mollusks lay eggs that hatch into small, free-swimming larvae called veliger.
Which type of fertilization is found in Mollusca?
The simplest molluscan reproductive system relies on external fertilization, but with more complex variations. All produce eggs, from which may emerge trochophore larvae, more complex veliger larvae, or miniature adults.
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.
Is fertilization in molluscs external or internal?
Molluscs have extreme variation in reproductive characteristics. A generic mollusc is dioecious with paired gonads. Eggs or sperm are released into the coelomic cavity and carried outside by ducts. Fertilization is external and the zygote develops into a gastrula and then a free-swimming trochophore larva.
Structure and Characteristics of Veliger Larva
The larval forms of Mollusca have the characteristics of the bivalve, gastropod, and scaphopod taxonomic classes. These are produced either by forming during the embryonic or trochophore larval stages of development. In bivalves, the veliger is referred to as the D-stage or pediveliger larva. Here, D-stage represents the early development stage.
Life Cycle of Veliger
Veligers will hatch from the egg capsules or develop from the free-swimming earlier larval stage. The larval forms of Mollusca that hatch from an egg capsule will pass through the trochophore stage in the egg capsule. The matured veligers are known as competence, where they settle to the bottom and metamorphose develop will into the juvenile stage.
Gastropods Veliger
The veliger is the second larval stage during the development of gastropods, which follows during the early stage of trochophores. In some species, the veliger stage passed with the egg capsule and the hatching stage to a juvenile. Some species of veliger are exclusively aquatic. They get feed from phytoplankton.
Bivalves Veliger
As like gastropods, the bivalves veliger are following a free-living trochophore stage. The exam for bivalves veliger is shipworms. It can hatch veligers directly with the trochophore, which begins with an embryonic stage within the egg capsule.
Scaphopods Veliger
The scaphopods will have the veliger larva similar to the bivalves. It is also known as tusk shells. The difference between both the bivalves and scaphopods can be found in the appearance of the adults. Here, the bi-lobed shell is developed to surround the larval body. But they never split into two and this will fuse along the ventral margin.