(photos of Chris Grossman, founder of diver.net website, USA: specimens from California)
This is large solitary form of californian species Anthopleura elegantissima. According to original description this species has the same morphological characters as Anthopleura elegantissima, except that Anthopleura sola being larger and solitary, while A. elegantissima is smaller and forms large aggregations of many asexually produced individuals.
Taxonomy:
Phylum Cnidaria
Class Anthozoa
Order Actiniaria
