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[From New Latin Ascidia, genus name, from Greek askidion, diminutive of askos, wineskin.]


1. (Zoology) 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. (Zoology) ascidian tadpole the free-swimming larva of an ascidian, having a tadpole-like tail containing the notochord and nerve cord
(Zoology) of, relating to, or belonging to the Ascidiacea


(əˈsɪd i ən)

1. any tunicate of the class Ascidiacea, having in the larval stage a notochord, a characteristic of the embryonic vertebrate.
2. belonging or pertaining to the class Ascidiacea.
[1855–60; < New Latin Ascidi(um) a tunicate genus < Greek askídion a small bag + -an1]
ThesaurusAntonymsRelated WordsSynonymsLegend:
Noun1.ascidian - minute sedentary marine invertebrate having a saclike body with siphons through which water enters and leavesascidian - minute sedentary marine invertebrate having a saclike body with siphons through which water enters and leaves
tunicate, urochord, urochordate - primitive marine animal having a saclike unsegmented body and a urochord that is conspicuous in the larva
Ascidiaceae, class Ascidiaceae - sometimes classified as an order: sea squirts
sea squirt - ascidian that can contract its body and eject streams of water
References in periodicals archive ?
the coral Siderastrea stellata, and ascidian (Ascidiacea) collected at the states of Paraiba and Rio Grande do Norte, Northeastern Brazil.
Exceptionally, in the colonial ascidian Botrylloides leachii (Savigny, 1816) a fully functional adult is formed from their common vascular system after ablation of all adults from the colony in just 10 d, thanks to their high blastogenetic potential.
According to the company, Plitidepsin is an investigational anticancer agent of marine origin, originally obtained from the ascidian Aplidium albicans.
Different bivalve, ascidian (tunicate) and polychaete species have been found to be the primary host for haplosporidian parasites.
Munoz, Clavaminols G-N, Six New Marine Sphingoids from the Mediterranean Ascidian Clavelina phlegraea, Tetrahedron, 65, 4384 (2009).
In this review, we will discuss the gene regulatory network in an ascidian, Ciona intestinalis.
Accumulation of paralytic shellfish poisoning toxins in bivalves and an ascidian fed on Alexandrium tamarense cells.
2002): <<Solution structure of ascidian trypsin inhibitor determined by nuclear magnetic resonance spectroscopy>>, Biochemistry, vol.
A significant 60% of silver salmon and ascidian, popular ingredients in Japanese cuisine, originate from Onagawa's fisheries.
Biofouling deterrent natural product from the ascidian Distaplia nathensis.