ascidian

American  

[uh-sid-ee-uhn] / əˈsɪd i ən /

noun

1. any solitary or colonial tunicate of the class Ascidiacea, exhibiting in the larval stage the vertebrate characteristics of a notocord and hollow nerve cord.

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adjective

1. belonging or pertaining to the class Ascidiacea.

ascidian British  

/ əˈsɪdɪən /

noun

1. any minute marine invertebrate animal of the class Ascidiacea, such as the sea squirt, the adults of which are degenerate and sedentary: subphylum Tunicata (tunicates)

2. the free-swimming larva of an ascidian, having a tadpole-like tail containing the notochord and nerve cord

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adjective

1. of, relating to, or belonging to the Ascidiacea

Etymology

Origin of ascidian

1855–60; < New Latin Ascidi ( um ) a tunicate genus ( ascidium ) + -an

Example Sentences

"Especially the ascidian larva is an ideal model for understanding early vertebrate development."

From Science Daily • Jan. 9, 2024

The scientists microscopically analyzed fertilized ascidian oocytes and realized that they were following very reproducible changes in cell shape leading up to the formation of the contraction pole.

From Science Daily • Jan. 9, 2024

The findings suggest that upon fertilization of ascidian oocytes, friction forces play a crucial role in reshaping and reorganizing their insides, heralding the next steps in their developmental cascade.

From Science Daily • Jan. 9, 2024

“The sponge or the ascidian that these things carry should offer it all the camouflage it needs,” Hosie said in a Guardian article.

From Slate • Jun. 23, 2022

Amphioxus therefore might well be considered an extremely simplified and degenerate Cyclostome, and the ascidian larva the last term of this degeneration-series.

From Form and Function A Contribution to the History of Animal Morphology by E. S. (Edward Stuart) Russell