The Collaborative International Dictionary of English v.0.48:

Suctorial \Suc*to"ri*al\, a. [L. sugere, suctum, to suck.]
   1. (Zool.) Adapted for sucking; living by sucking; as, the
      humming birds are suctorial birds.
      [1913 Webster]

   2. (Zool.) Capable of adhering by suction; as, the suctorial
      fishes.
      [1913 Webster]

WordNet (r) 3.0 (2006):

suctorial
    adj 1: adapted for sucking or clinging by suction