Table of Contents
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 evolutionary significance of trochophore larva?
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.
Do sponges have trochophore larvae?
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 larva differ from a Veliger larva?
Unlike the trochophore, the newly hatched veliger may have or will develop many of the characteristic features of the adult including such structures as a muscular foot, eyes, rhinophores, a fully developed mouth, and a spiral shell (in fact, the veliger of nudibranchs has a shell, although the adult does not).
Where is trochophore larvae found?
Mollusca
Trochophore larvae are most commonly found in Mollusca and Annelida. So the correct option is A) Annelida and Mollusca. Note: Many organisms cannot develop into their adult forms just after birth and hence go through various developmental stages.
What is Megalopa larva?
Megalopa larva It has a broad and crab-like unsegmented cephalothorax. The carapace is produced anteriorly into a median spine. The eyes are large, stalked and compound. All the thoracic appendages are well formed of which the last 5 pairs are uniramous.
Does echinoderms have trochophore larva?
Trochophore. Hint: Radial symmetry organisms known as echinoderms that have endoskeleton which is observed in the spine and calcareous. There are numerous stages in which larvae of the echinoderms pass. Tornaria is a kind of planktonic larvae and sea cucumber is an auricularia kind of larvae.
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, a water eddy is created. In this way they control the direction of their movement.
Do trochophore larvae have eye spots?
The early trochophore larvae of the errant annelid Platynereis dumerilii have a single pair of ventral eyespots, whereas older nectochaete larvae have an additional two pairs of dorsal eyes that will develop into the adult eyes.
What phyla have trochophore larva?
Lophotrochozoa
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 all mollusks have trochophore larvae?
Molluscs include such familiar creatures as clams, oysters, snails, and octopi. They share a distant common ancestor with the annelid worms, an evolutionary heritage suggested by their larval form, called a trochophore larva, found in all molluscs and in certain marine annelids called polychaete worms.
What is mysis larva?
2 or mysis stage plural -es : a larva of higher crustaceans (as macrurans and peneids) having all the thoracic appendages biramous.