A new cheilostome bryozoan with gigantic zooids from the North-West Pacific.

Gontarella gigantea gen. et sp. nov. is described from two stations, one in the Sea of Okhotsk and the second on the Pacific side of the Small Kuril Arc. This membraniporiform anascan cheilostome bryozoan has very large zooids, the largest known among extant sheet-like encrusting anascans. Comparative data on similar sheet-like cheilostomes gathered from the literature shows that the new species represents a conspicuous outlier in size, with the surface area of the zooid being approximately twice that of the next largest species. Skeletal evidence, including the lack of ovicells, indicates that G. gigantea belongs within the malacostegan family Electridae. The gigantic ancestrula suggests that the species has a cyphonautes larva about 1 mm in maximum dimension.