A. papillosa sensu stricto is an amphiboreal species with maximum uncorrected p-distance of 1.6% between individuals (Carmona et al., 2013), which is common along the Atlantic coasts of Europe and North America and in the north-eastern Pacific. Kienberger et al. (2016) verified with molecular sequencing specimens from Alaska and Washington State USA.
Specimen with distinct white wine glass mark on head from Alaska, USA. July 2013. © E. McKittrick.