Acetabulum
An acetabulum is a muscular organ of attachment, commonly called a sucker. It is typically associated with helminths that must anchor firmly to host tissues.
In trematodes (flukes), the acetabulum often refers to the ventral sucker used to maintain position against fluid flow or host movement. In cestodes (tapeworms), comparable sucker structures help the scolex attach to the intestinal wall.
Why it matters: Attachment structures are essential for parasite survival in the host and are often key features used in identification and classification.
