MBL March Madness: Sea Squirt

Sea Squirt (Ciona) embryo. Credit: Laurence Lemaire
MBL March Madness: Sea Squirt (Ciona intestinalis)

The sea squirt Ciona is a marine invertebrate closely related to vertebrates. Its simplicity and invariant cell lineage make it a powerful model for the study of development, evolution, and neurobiology. Ciona has provided fundamental insights into the ancestry and evolution of vertebrate systems, including neural crest cells, heart morphogenesis, and expansion of the central nervous system.

Cool facts

  • Its Latin name literally translates to "Pillar of Intestines."
  • Ciona intestinalis is a tunicate, the only animals to synthetize cellulose.
  • Its larvae have one of the smallest functioning brains.

(ID Card Photo Credit: Laurence Lemaire | Equipment: Zeiss 880 confocal microscope with Airyscan detector)

Select Publications

Dehal P, et al. The draft genome of Ciona intestinalis: insights into chordate and vertebrate origins. Science. 2002 Dec 13;298(5601):2157-67.

Imai KS, Levine M, Satoh N, Satou Y. Regulatory blueprint for a chordate embryo. Science. 2006 May 26;312(5777):1183-7.

Cao, C., Lemaire, L.A., Wang, W. et al. Comprehensive single-cell transcriptome lineages of a proto-vertebrate. Nature 571, 349–354 (2019).

Ryan K, Lu Z, Meinertzhagen IA. The CNS connectome of a tadpole larva of Ciona intestinalis (L.) highlights sidedness in the brain of a chordate sibling. Elife. 2016 Dec 6;5:e16962.

Stolfi A, Gainous TB, Young JJ, Mori A, Levine M, Christiaen L. Early chordate origins of the vertebrate second heart field. Science. 2010 Jul 30;329(5991):565-8.


Division: Deuterostome

Deuterostomia may not sound familiar, but it should: you are a deuterostome! Most deuterostomes belong to one of two groups that include most of its members—echinoderms, which includes animals such as the spiny-skinned starfish, sea urchins, and their relatives, and chordates, which include fish and other vertebrates (including humans). Learn more about the Deuterostome Division.

Meet the Other Deuterostome Organisms

What is MBL March Madness?

Based on the March Madness NCAA basketball tournament, during MBL March Madness, popular MBL organisms face off for your votes. YOU have the opportunity to decide what organism is crowned victorious by voting for your favorite organisms in a series of head-to-head match-ups. Voting will take place on the СƵ social media channels from March 29 - April 7. Learn more and download a bracket at mbl.edu/march-madness.