Definition: Gravel is an environmental material which is composed of pieces of rock that are at least two millimeters (2mm) in its largest dimension and no more than 75 millimeters.
Definition: The marine benthic biome (benthic meaning 'bottom') encompasses the seafloor and includes such areas as shores, littoral or intertidal areas, marine coral reefs, and the deep seabed.
Known occurrences, collected specimens and observations of Actinarctus physophorus Grimaldi de Zio, D' Addabbo Gallo, Morone De Lucia, Vaccarella & Grimaldi 1982. View this species on GBIF