The high proportion of cosmopolitan species in pelagic individuals makes it extremely tedious to differentiate between closely related members.

[2] Because of limited study and challenging experimentation, not all of the Cyanea species from the North Atlantic are considered valid.

[3] Protein and medusae analysis from Michael N. Dawson of the University of New South Wales confirm that Cyanea annaskala is a valid species, morphologically distinct based on differences in bell mass, number of nematocyst clusters, pits in coronal muscle folds, and other morphological characteristics.

Some of the other morphological characteristics that have been compared include the number of coronal and radial muscle folds, and the depth of primary and secondary marginal clefts.

The bell width is usually between 25 cm and 1 m[6] Their oral arms usually have a base that is not thickened, between 17-24 shallow coronal muscle folds, and no pits in their muscle folds[4] Cyanea annaskala are endemic to the waters of South Eastern Australia, spanning depths from shallow waters close to the shore to 20 m below the surface.

[9] During the summer of 1950 and 1961, 4 young men were stung in the eyes while swimming in Port Phillip Bay during a C. annaskala infestation.

[11] There was also an infestation during the 1997-1998 summer and swimmers were warned to stay out of the waters by the Victorian Environmental Protection Authority after hundreds of reported stingings!

[13] Many efforts to understand the potent toxicity of the Cyanea sting have spanned the realm of biochemical technique.