these are found in pteropods on the acetabuliferous arms- those on the lateral arms are lateral suckers, those on the median arm are median suckers- and used for capturing prey. Sometimes the penis has a suckers, and when this is absent a median footlobe tubercle takes its function.
In Heteropoda the wing sometimes has a sucker.

Alternative forms for sucker : lateral sucker, lateral suckers, median sucker, median suckers, suckers.