Neptunes necklace and sea lecttuce | ©Steve Axford (Australia)
Hormosira banksii (Fucales - Hormosiraceae) is a species of brown algae found in Australia and New Zealand. It is a distinctive algae made up of strings of hollow, water-filled, round or oval-shaped beads joined together by a short stalk , by what is commonly known as Neptune’s necklace, Neptune’s pearls, Sea grapes or Bubbleweed .
Hormosira banksii often occurs in vast colonies forming a thick covering over most of the rock surface at mid-tide levels down to the Galeolaria zone on some rocky shores. The dense colony of fronds can form a protective microhabitat where many mollusks, worms and small crustaceans shelter .
On the other hand, the Sea lettuce is an edible green algae in the genus Ulva (Ulvales - Ulvaceae).