Do molluscs have trochophore larvae?
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.
Is a veliger larvae?
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.
Which mollusc class lacks the veliger vs trochophore larval stage?
Reproduction in cephalopods is different from other mollusks in that the egg hatches to produce a juvenile adult without undergoing the trochophore and veliger larval stages. In the shell-bearing Nautilus spp., the spiral shell is multi-chambered.
What is the larval stage of mollusks called?
trochophore larva
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.
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 phylum are trochophore larvae?
phylum annelida
They are triploblastic, bilaterally symmetrical and segmented Metazoa. Some of the annelids belong to the Lophotrochozoa lineage. Trochophore larva occurs in phylum annelida.
What is the larva of Mollusca?
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.
Which larva is found in Mollusca?
Trochophore larva is the larva found in mollusca and annelids.
What is the difference between a trochophore larva and a Veliger larva?
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 are the 8 classes of animals that fall under the phylum Mollusca?
The Phylum Mollusca consist of 8 classes: 1) the Monoplacophora discovered in 1977; 2) the worm-like Aplacophora or solenogasters of the deep sea; 3) the also worm-like Caudofoveata; 4) the Polyplacophora, or chitons; 5) the Pelecypoda or bivalves; 6) the Gastropoda or snails; 7) the Scaphopoda, or tusk shells; and 8) …
In which phyla of animals is the larval trochophore stage found?
Trochophores exist as a larval form within the trochozoan clade, which include the entoprocts, molluscs, annelids, echiurans, sipunculans and nemerteans. Together, these phyla make up part of the Lophotrochozoa; it is possible that trochophore larvae were present in the life cycle of the group’s common ancestor.
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.
When do veliger larvae develop in a mollusk?
Many gastropod (snails and their allies) and bivalve (clams, mussels, oysters and scallops) molluscs pass through a trochophore larval stage before developing into veliger larvae.
What kind of larva does a bivalve have?
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 kind of shell does a veliger have?
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. A dorsal shell gland secretes the shell of the veliger.
Where does the velum of a mollusk come from?
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. The velum is used for swimming, feeding, and gas exchange, and it is resorbed or lost as the mollusk metamorphoses into its adult stage.