Callopora craticula is an encrusting bryozoan that forms small circular patches, typically 1 cm across and white-yellow in colour. The species colonises a range of substrates including stones, shells, barnacles and other bryozoan species (e.g. Phidolopora sp.) in the intertidal zone and shallow subtidal waters.
Callopora craticula is circumpolar cool temperate species, that is widely distributed in the Boreal-Arctic zone. It ranges south through Scotland to northern England and the south-western coast on the Isle of Man. Its occurrence in the western Atlantic is uncertain. It has been recorded in the western Pacific from Japan and Saint Lawrence Island.