Specimens that seem more translucent may appear brown and aqua, or almost white in colour.

The primary tentacles (anchors) may range in appearance from orbicular to suborbicular.

Although similar in appearance, there are white nematocyst clusters present in both perradii and interradii of Haliclystus octoradiatus.

Also, the anchors of Haliclystus octoradiatus are large, globular, and knob-shaped.

Haliclystus octoradiatus has been seen eating small invertebrates, amphipods, and sea spiders.