ascidian

[ uh-sid-ee-uhn ]

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.

adjective

1. belonging or pertaining to the class Ascidiacea.

ascidian

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

adjective

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

Word History and Origins

Origin of ascidian¹

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

Example Sentences

Therefore, ascidians are often used as model organisms to study the early embryonic development of vertebrates to which humans belong.

From Science Daily

They found that the ancestors of one group of palaemonid shrimp had all once lived inside ascidians, a group of tubular filter-feeding organisms that includes tunicates and sea squirts.

From Science Magazine

There are several advantages to studying embryonic development in sea squirts — which are also known as ascidians.

From Nature

In the sea and along its shores swarm organisms of the other living world — marine diatoms, crustaceans, ascidians, sea hares, priapulids, coral, loriciferans and on through the still mostly unfilled encyclopedia of life.

From New York Times

An egg does not come from a stone, and the ascidian did not come from a lifeless rock.

From Project Gutenberg