Ciona savignyi is a Pacific species of the order Ascidia (sea squirts), marine organisms which are sessile filter feeders as adults. The genome of Ciona savignyi was sequenced in 2003 using Sanger technology and the ~13X assembly was submitted to NCBI in 2004. The assembly is available in NCBI under BioProject PRJNA1435. All raw sequence reads are available in the NCBI Trace Archive.