Actinia bermudensis attaches itself to a rock surface by its pedal disc, which can reach 4 centimetres in width.

The oral disc has a central mouth and two irregular whorls of 96 to 140 short, retractable, tapering tentacles which are armed with cnidocytes.

It is usually found near the base of rock walls, under overhangs, in caves, in crevices and under boulders.

[3] The acrorhagi of Actinia bermudensis are used to discourage other individuals from moving into the anemone's territory.

In this case the juvenile sea anemones are brooded by the parent in the gastrovascular cavity until they have grown sufficiently large to be liberated into the water column.