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Related to Ascidiacea: Larvacea, Thaliacea


[From New Latin Ascidia, genus name, from Greek askidion, diminutive of askos, wineskin.]
American Heritage® Dictionary of the English Language, Fifth Edition. Copyright © 2016 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.


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
Collins English Dictionary – Complete and Unabridged, 12th Edition 2014 © HarperCollins Publishers 1991, 1994, 1998, 2000, 2003, 2006, 2007, 2009, 2011, 2014


(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]
Random House Kernerman Webster's College Dictionary, © 2010 K Dictionaries Ltd. Copyright 2005, 1997, 1991 by Random House, Inc. All rights reserved.
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
Based on WordNet 3.0, Farlex clipart collection. © 2003-2012 Princeton University, Farlex Inc.
References in periodicals archive ?
Ascidiidae Herdman, 1882 (Tunicata: Ascidiacea) on the Pacific coast of Panama.
Ascidians (Class Ascidiacea), also known as tunicates or sea squirts, are marine invertebrates that are sessile suspension feeders and usually attached to a substrate.
and Haliclona sp., the coral Siderastrea stellata, and ascidian (Ascidiacea) collected at the states of Paraiba and Rio Grande do Norte, Northeastern Brazil.
Belonging to phylum Chordata, class Ascidiacea, these invertebrates have tissue and organ complexity incipient to that of vertebrates (see Fig.
Members of the class Ascidiacea were not considered in this study because this taxon was excluded during the first years of sampling.
3 All crabs 2 3 Majidae Oregoniidae, Chionoecetes bairdi Chionoecetes opilio 3 Hyas lyratus 2 All Sipuncula 3 All Echiuridae 19 27 All Bryozoa Clypeasteroida, sand dollar 2 All Ascidiacea, tunicates 7 Chelysoma spp.
Toxicity of Hg, Cu and Cr on early developmental stages of Ciona intestinalis (Chordata, Ascidiacea) with potential application marine water quality assessment.
The species sampled include more than one member of each of the three orders in class Ascidiacea, providing substantial diversity for comparative research.
Species commonly recorded included Polychaeta (Spirorbis sp., Galeolaria hystrix, Pomatoceratos carniferus), Bryozoa (Beania sp., Bitectipora sp., Schizomittina, Platonea sp., Tubulipora sp., Smittoidea maunganuiensis, Cellaria sp.), Hydrozoa (Family Sertularidae), and Ascidiacea (Didemnum sp.).