What is a mollusk larvae 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).
What kind of larvae do gastropod molluscs have?
The veliger is the characteristic larva of the gastropod, bivalve and scaphopod taxonomic classes. It is produced following either the embryonic or trochophore larval stage of development.
What are the three parts of a mollusk?
The mollusk body can generally be divided into three regions: the head, the foot, and a cluster of internal organs called the visceral mass.
What do we call the free swimming larva that has the beginnings of a foot shell and mantle?
trochophore larvae
The larvae (which develop from ciliated, free-swimming trochophore larvae) have the beginnings of a foot, shell and mantle. In many molluscs the trochophore larval stage is passed in the egg, and the veliger hatches to become the only free-swimming stage.
What are the 3 main mollusk larval stages?
In some mollusks, the zygote hatches and undergoes two larval stages, trochophore and veliger, before becoming a young adult; bivalves may exhibit a third larval stage, glochidia.
What is meant by trochophore larva?
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 are the larval stages of crustaceans?
LARVAL FORMS OF CRUSTACEA
- NAUPLIUS LARVA. Discovered by Muller in 18th century, the Nauplius larva is the first fundamental stage in all crustaceans that sometimes hatches from the egg and sometimes passes inside the egg.
- METANAUPLIUS LARVA.
- PROTOZOEA LARVA.
- ZOEA LARVA.
- MYSIS LARVA.
- SCHIZOPODA LARVA.
- PHYLLOSOMA LARVA.
Do all molluscs have larval stage?
Essentially all mollusks have a muscular foot that is primarily used for locomotion but may be adapted for different purposes in different species. The mollusk life cycle includes one or more juvenile, larval stages.
What is the head of a mollusk called?
The molluscan body, which contains all the visceral elements (such as the digestive tract, gonads, and heart), is connected to the mantle by dorsoventral musculature. The head, when present, has tentacles called captacula in scaphopods, labial palps in bivalves, head tentacles in gastropods, and arms in cephalopods.
What is another term for a mollusk shell?
shellfish. Noun. ▲ Any of various edible European bivalve mollusks, of the family Cardiidae, having heart-shaped shells. cockle.
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.
What is the larva of a mollusk called?
In more advanced mollusks (such as in marine gastropods and bivalves), the trochophore larva develops into a veliger larva. In these generally planktotrophic larvae, the girdle of ciliated cells widens to form a velum that entraps food and also propels the microscopic mollusk through the water.
What is a trochophore in mollusks?
Trochophore, also called trochosphere, small, translucent, free-swimming larva characteristic of marine annelids and most groups of mollusks. In some mollusks (such as gastropods and bivalves), the trochophore develops into a second stage, the veliger (q.v.), before metamorphosing to adult form.
What is the life cycle of a mollusk?
What is a mollusks life cycle? 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. Click to see full answer.
What are the members of the phylum Mollusca called?
The members are known as molluscs or mollusks (/ˈmɒləsk/). Around 85,000 extant species of molluscs are recognized. The number of fossil species is estimated between 60,000 and 100,000 additional species. Molluscs are the largest marine phylum, comprising about 23% of all the named marine organisms.