What is ascidian larva?
What is ascidian larva?
Ascidian larvae exhibit the simplest chordate body plan, with a head and a tail containing a notochord, three rows of muscle cells, and a hollow dorsal nerve. I have identified four novel maternal genes expressed in ascidian eggs that may be integral to the larval chordate phenotype.
Which characteristic can be seen in the body of Ascidia sp?
Ascidiacea, commonly known as the ascidians, tunicates (in part), and sea squirts (in part), is a polyphyletic class in the subphylum Tunicata of sac-like marine invertebrate filter feeders. Ascidians are characterized by a tough outer “tunic” made of a polysaccharide.
What is ascidian tadpole?
Noun. 1. ascidian tadpole – free-swimming larva of ascidians; they have a tail like a tadpole that contains the notochord. Ascidiaceae, class Ascidiaceae – sometimes classified as an order: sea squirts.
What marks the dorsal side of an ascidian body?
The circum-notochord side marks the area from which the notochord forms and which is conventionally referred to as ‘dorsal’ and ‘anterior’ in amphibian and ascidian embryos, respectively.
What is the meaning of ascidian?
Definition of ascidian : any of a class (Ascidiacea) of solitary or colonial sessile tunicates having an incurrent and excurrent siphon. — called also sea squirt.
What type of metamorphosis is found in ascidian tadpole larva?
The ascidian tadpole larva undergoes a retrogressive metamorphosis. Retrogressive metamorphosis is a type of metamorphosis in which the free-swimming larva possessing advanced characteristics transforms into a sedentary adult with degenerative characteristics.
Which of the following feature is seen in Ascidia larva?
Explanation: Ascidia Larva is highly motile with the presence of a tail; also, the tail region has the endodermal notochord; thus, option C is right about the ascidian larva.
Is ascidian a tunicate?
The tunicates are divided into three classes: Ascidiacea (ascidians, or sea squirts), Appendicularia (Larvacea), and Thaliacea.
What are the common chordate features of ascidian tadpole?
Although their adult form is a sessile lter feeder, its tadpole larva has characteristic features of the chordate group: a dorsal neural tube, a notochord surrounded by muscle and a ventral endodermal strand Satoh (2003) . …
How do Ascidians feed?
Ascidians filter their food from the water-column via an oral siphon that brings water into the branchial sac where food items such as microalgae are filtered onto a mucus net; water, feces and gametes are expelled through an excurrent siphon.
What is yellow cytoplasm?
The yellow, myoplasmic crescent is a localized cytoplasmic region preferentially distributed to the muscle and mesenchyme lineage cells during early development of ascidian eggs. It consists of a collection of lipid pigment granules with numerous adherent mitochondria underlain by a specific cytoskeletal domain.
Which of the following is the feature of ascidian adult during metamorphosis?
The representative characteristic of ascidians is their vertebrate-like, tadpole shape at the larval stage. Ascidians lose the tadpole shape through metamorphosis to become adults with a nonmotile, sessile body and a shape generally considered distinct from that of vertebrates.