Bouchemousse S, Liautard-Haag C, Bierne N, Viard F.
Mol Ecol. 2016 Nov;25(21):5527-5542. doi:10.1111/mec.13854
Distinguishing contemporary hybridization from past introgression with postgenomic ancestry-informative SNPs in strongly differentiated Ciona species.
The only hybrids detected are F1 and have a C. int mitochondrial haplotype.