- any solitary or colonial tunicate of the class Ascidiacea, exhibiting in the larval stage the vertebrate characteristics of a notocord and hollow nerve cord.
- belonging or pertaining to the class Ascidiacea.
Origin of ascidian
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018
Examples from the Web for ascidian
The ascidian has only one eye inside its useless brain, while the tadpole and all other vertebrates have two from the very first.
So that in this respect the ascidian larva is nearer to the original type than the tadpole or any other existing animal.
The ascidian when born is a tiny, free-swimming, tadpole-like creature with a slender finned tail.Elementary Zoology, Second Edition
Vernon L. Kellogg
Chabry had published in 1887 some interesting results on the Ascidian egg, which strongly supported the Roux-Weismann theory.Form and Function
E. S. (Edward Stuart) Russell
The beginning of man an ascidian—his ultimate development as an angel, a pear-shaped, transparent bag.
- 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)
- ascidian tadpole the free-swimming larva of an ascidian, having a tadpole-like tail containing the notochord and nerve cord
- of, relating to, or belonging to the Ascidiacea
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012