Cladonema pacificum is a colonial hydrozoan (family Cladonematidae) distributed in shallow coastal waters of the western Pacific, with hydroid stages forming small branching colonies and medusa stages distinctive for their branched tentacles bearing adhesive tips for prey capture, enabling a crawling behavior on surfaces unusual for free-swimming medusae. The species is a model for investigating hydrozoan regenerative capacity and the evolution of tentacle-based locomotion. Genomic data have been generated for this species and are available in public databases, enabling comparative studies of cnidarian evolution and ecology.