Introduction: High-spined commensal hydroids (Hydractinia altispina) occur on scaly dogwhelks, protecting them from predators up to a depth of 24m.
Distribution: From the Orange River mouth north to Luderitz.
Diet: Microscopic animals
Colouration: An orange coat is formed on shells of scaly dogwhelk.
Breeding: Has a polyp stage that produces eggs
Max size: Polyps 2mm