The Collaborative International Dictionary
Suctorial \Suc*to"ri*al\, a. [L. sugere, suctum, to suck.]
(Zo["o]l.) Adapted for sucking; living by sucking; as, the humming birds are suctorial birds.
(Zo["o]l.) Capable of adhering by suction; as, the suctorial fishes.
Douglas Harper's Etymology Dictionary
1826, "pertaining to or adapted for sucking," from Modern Latin suctorius, from Latin suct-, past participle stem of sugere "to suck" (see sup (v.2)). Meaning "having a sucking organ" is from 1829.
Wiktionary
a. 1 (context zoology English) Adapted for sucking; living by sucking. 2 (context zoology English) Capable of adhere by suction.
WordNet
adj. adapted for sucking or clinging by suction
Wikipedia
Suctorial pertains to the adaptation for sucking or suction, as possessed by marine parasites such as the Cookiecutter shark, specifically in a specialised lip organ enabling attachment to the host.
Suctorial organs of a different form are possessed by the Solifugae arachnids, enabling the climbing of smooth, vertical surfaces.
Another variation on the suctorial organ can be found as part of the glossa proboscis of Masarinae (pollen wasps), enabling nectar feeding from the deep and narrow corolla of flowers.
Usage examples of "suctorial".
In the paddles of the extinct gigantic sea lizards, and in the mouths of certain suctorial crustaceans, the general pattern seems to have been thus to a certain extent obscured.
The mouths were many, small, red and suctorial, without teeth that Nestor could see.
But as it came closer I saw it was a shapeless thing with a trumpet-like suctorial disk, the orifice ringed with small fangs and tentacles—a mud-sucker, a big one.