1st Record: Plymouth/England/Plymouth Harbour (2003, Bishop et al. 2015a). Genetic analysis suggests that introgression between C. robusta and C. intestinalis has been occurring since ~15,500 years (95%CI 4,300-56,800 y), before human transport.
Queen's Battery, Plymouth/England/Plymouth Harbour (molecular ID, coexisting with C. intestinalis here, Sato et al. 2012, molecular ID); Plymouth/England/Plymouth Harbor (2011, Brunetti et al. 2015. molecular ID); Torquay, Cornwall/England/Celtic Sea (2011-2012, Type A, Bishop et al. 2015, molecular ID)