Todd Mintz / Sharknose cleaner goby (Gobiosoma evelynae) pair sheltering in hard coral, Netherlands Island, Dutch Antillies, Caribbean

Nick Upton / Keelworm tubes (Pomatoceros lamarcki) attached to sandstone boulder exposed on a low spring tide, North Berwick, East Lothian, UK, July.

Nick Upton / Close up of Keelworm tube (Pomatoceros lamarcki) attached to sandstone boulder exposed on a low spring tide, North Berwick, East Lothian, UK, July.

Jean E. Roche / Calcerous deposits of the tubeworm "Cascail" {Ficopomatus enigmatus} introduced to Europe from Australia. Intertidal zone, Candillargues, Languedoc, France

GEORGETTE DOUWMA / Christmas tree worm {Spirobranchus giganteus} embedded in live coral.

Juergen Freund / Colonial tube worms feeding {Filogranella elatensis} Indo-pacific

Doug Gimesy / Little pied cormorant (Microcarbo melanoleucos) perched on intertidal rocks covered with Intertidal tubeworms (Galeolaria caespitosa) and molluscs, Victoria, Australia.

Doug Gimesy / Little pied cormorant (Microcarbo melanoleucos), wings stretched to dry or warm wings in sun, standing on intertidal rocks covered with Intertidal tubeworms (Galeolaria caespitosa) and molluscs, Victo...

Doug Gimesy / Little pied cormorant (Microcarbo melanoleucos), wings stretched to dry or warm wings in sun, standing on intertidal rocks covered with Intertidal tubeworms (Galeolaria caespitosa) and molluscs, Victo...

Doug Gimesy / Little pied cormorant (Microcarbo melanoleucos) standing on intertidal rocks covered with Intertidal tubeworms (Galeolaria caespitosa) and molluscs, Victoria, Australia.

Doug Gimesy / Little pied cormorant (Microcarbo melanoleucos) on intertidal rocks covered with mollusc , seaweed and Intertidal tubeworms (Galeolaria caespitosa) encrusting exposed rock, Victoria, Australia.

David Hall / Subtidal organisms found in the extreme tidal current that occur at Nakwakto Rapids, including Gooseneck barnacles (Pollicipes polymerus), mussels, kelp, red algae, coralline algae and calcareus tubew...