Which type of worms have an oral and ventral cup-shaped sucker in their adult stage?

The correct answer is Trematodes, which are commonly known as flukes. Adult trematodes are characterized by having a distinct morphology that includes an oral sucker and a ventral sucker, also referred to as a pharyngeal sucker. These suckers are essential adaptations that allow trematodes to attach to their host’s tissues, facilitating nutrient absorption and protecting them from being washed away or expelled by the host's immune responses.

Trematodes have a complex life cycle that often involves multiple hosts, including intermediate and definitive host stages. This complexity, along with their anatomical features, distinguishes them from other worm types.

For example, nematodes, or roundworms, do not have suckers; they have a more cylindrical body shape and rely on a different feeding mechanism. Cestodes, or tapeworms, have a segmented body composed of proglottids and utilize hooks and suckers, but their overall morphology is quite different from trematodes, lacking the cup-shaped suckers. Platyhelminthes is a broader phylum that encompasses both trematodes and cestodes, but does not specifically refer to the morphological traits of the suckers found in trematodes.

Therefore, recognizing