This pale reddish brown elongated sac-like structure with a club shaped tip and narrow base is part of a red seaweed which grows in a clump, attached to the sea floor by a discoid holdfast. The inside of the bladder appears to be filled with mucilage. This bladder was about 50 mm long.
This seaweed can grow up to 16 cms in length. The outer walls of sacs growing in rough waters are said to be thicker than those in calm waters. The secretory cells lining the inside of the sacs produce highly viscous mucilage.
Spotted along the high tide mark along with other sea weeds on a sandy beach - Western Port Bay.
Occur in Seagrass beds upto a depth of 20 mts.