Tony Wu / Humpback whale (Megaptera novaeangliae) adult female at rest. The tubercles on the whale's head are clearly visible, as are the barnacles (Coronula diadema), whale lice (Cyamus boopis), and hairs on t...

Floris van Breugel / Lines adorn the fractured sandstone rocks along the Barnacle (Cirripedia) and Sea snail inhabitated shores of Palos Verdes peninsula, California, USA

Wild Wonders of Europe / Quinta / Limpets and Barnacles on rock, Alentejo, Natural Park of South West Alentejano and Costa Vicentina, Portugal, June 2009

Shane Gross / China rockfish (Sebastes nebulosus) resting among Giant acorn barnacles (Balanus nubilus), Browning Pass, Queen Charlotte Strait, British Columbia, Canada

David Fleetham / Banded spiny lobster (Panulirus marginatus) infested with goose barnacles (Lepas anatifera), Hawaii.

Jack Dykinga / Low tide exposing Barnacles and Mussels covering rocky shoreline with cascading stream, The Great Bear Rainforest, British Columbia, Canada. September 2010.

David Fleetham / Gooseneck barnacle (Lepas anatifera) group feeding at night. Pacific Ocean, Philippines.

Jeff Foott / Barnacles (Cirripedia) and Whale lice (Cyamidae) on skin of Grey whale (Eschrichtius robustus). San Ignacio Lagoon, Baja California Sur, Mexico.

Jeff Foott / Barnacles (Cirripedia) and Whale lice (Cyamidae) on skin of Grey whale (Eschrichtius robustus). San Ignacio Lagoon, Baja California Sur, Mexico.

David Hall / Northern basket stars (Gorgonocephalus eucnemis), branching and staghorn bryozoans, calcareous tubeworms, snails and barnacles, Baranof, Alaska, USA. August.

David Hall / Split level of Acorn barnacles (Balanus glandula) just below the surface, Seven Tree Island, Browning Pass, Queen Charlotte Strait, British Columbia, Canada. September.

David Hall / Acorn barnacles (Semibalanus cariosus) and (Balanus glandula), Mussels (Mytilus sp.), and Plumose anemones (Metridium senile) underwater at high tide, Seven Tree Island, Browning Pass, Queen Charlotte...

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...

David Hall / Gooseneck barnacles (Pollicipes polymerus) found only at Nakwakto Rapids, which has one of the strongest tidal currents in the world. Also seen are Vancouver featherduster worms (Eudistylia vancouveri...

David Hall / Gooseneck barnacles (Pollicipes Polymerus) amongst kelp, Nakwakto Rapids, Slingsby Channel, British Columbia, Canada. September.

David Hall / Pygmy rock crab (Cancer oregonensis) in the empty shell of a Giant Acorn Barnacle (Balanus nubilus). Browning Pass, Queen Charlotte Strait, British Columbia, Canada. September.

David Hall / Goose neck barnacles (Pollicipes polymerus), Nakwakto Rapids, Slingsby Channel, British Columbia, Canada. May. This variety with deep red color is only found in this location,

Heather Angel / Winkles clustered in empty Oyster shells to avoid drying out at low tide. Barnacles also on rocky shore. Dalian, Liaoning Province, China.

Rick Price / Scaly Barnacle (Tetraclita squamosa) on rock. Bigge Island, Bonaparte Archipelago, The Kimberley, Western Australia.

Tony Wu / Sacculina barnacle infested crab, Tonga, Pacific Ocean.

Nick Upton / Common limpets (Patella vulgata) and Poli's stellate barnacles (Chthamalus stellatus) on rocks exposed at low tide. Kimmeridge, Dorset, England, UK. July.

Nick Upton / Green-leaf worm (Eulalia viridis) scavenging on rocks encrusted with Barnacles (Semibalanus balanoides). Treyarnon Bay, Cornwall, England, UK. September.

Ernie Janes / Old posts covered in barnacles on beach,Titchwell Marsh, Norfolk, England, UK, September.

Ernie Janes / Old posts covered in barnacles on beach,Titchwell Marsh, Norfolk, England, UK, September.

Paul Williams / Ochre starfish (Pisaster ochraceus) Goose barnacles (Pollicipes polymerus) California mussel (Mytilus californianus) and Giant green anenome (Anthopleura xanthogrammica) in rock pool, Vancouver Island...

Paul Williams / Ochre starfish (Pisaster ochraceus), Goose barnacles (Pollicipes polymerus) and California mussel (Mytilus californianus) in rock pool, Vancouver Island, British Columbia, Canada, July.

Paul Williams / Goose barnacles (Pollicipes polymerus) and California mussel (Mytilus californianus), Vancouver Island, British Columbia, Canada, June.

Paul Williams / Goose barnacles (Pollicipes polymerus) and California mussel (Mytilus californianus), Vancouver Island, British Columbia, Canada, June.

Magnus Lundgren / Wild Wonders of China / Barnacles and oysters on mangrove in Ha Pak Nai, a mudflat in the Yuen Long District, Hong Kong, China.

David Fleetham / Humpback whale (Megaptera novaeangliae) pectoral fin with Whale barnacles (Coronula diadema) upon it. Whale at surface, Hawaii.

David Fleetham / Humpback whale (Megaptera novaeangliae) breaching with town of Lahaina in background. West Maui, Hawaii. February 2010.

Robert Thompson / Dog whelk (Nucella lapillus) and Common barnacle (Semibalanus balanoides) on rock. Mill Quarter Bay, Killard Point National Nature Reserve, Strangford, County Down, Northern Ireland. February.

Robert Thompson / Painted top shell (Calliostoma zizyphinum) and Common barnacle (Semibalanus balanoides) on rock at edge of Strangford Lough. Mill Quarter Bay, Killard Point National Nature Reserve, Strangford, County...

Tony Wu / Ram's horn squid / Little post horn squid (Spirula spirula) internal shell with Pelagic goose barnacles (Lepas sp.). South Africa, Atlantic Ocean.

Olga Kamenskaya / Barnacle (Balanus balanus) underwater, off the coast of Svalbard, Norway, September.

Nick Upton / Group of Dog whelks (Nucella lapillus) in an intertidal rock crevice among Acorn barnacles (Balanus perforatus) and Beadlet anemones (Actinia equina), Cornwall, UK, April.

Solvin Zankl / Giant barnacles (Austromegabalanus psittacus) Comau Fjord, Patagonia, Chile, Atlantic Ocean

Tony Wu / Southern Humpback whale (Megaptera novaeangliae australis) dorsal fin detail with Acorn barnacles (Coronula diadema) and whale lice (Cyamus boopis) visible, South Africa

Alex Hyde / Pelagic Gooseneck Barnacle / Smooth Gooseneck Barnacle colony (Lepas anatifera) attached to plastic bottel washed up on a beach following heavy storms. This species is found attached to flotsam floati...

Willem Kolvoort / Goose barnacles (Lepas anatifera) growing on underwater root of Mangrove tree, Picard island, Aldabra, Indian Ocean

Willem Kolvoort / Goose barnacles (Lepas anatifera) and other organisms growing on the outer reef, Aldabra, Indian Ocean

Nick Upton / Patches of Wart lichen (Verrucaria mucosa / Wahlenbergiella mucosa) growing on rocks exposed at low tide alongside young Acorn barnacles (Semibalanus balanoides), Millook Haven, Cornwall, UK, Septembe...

Nick Upton / Common limpet (Patella vulgata) and young Acorn barnacles (Semibalanus balanoides) attached to rocks on seashore, north Cornwall, UK, September.

Brent Stephenson / Humpback whale (Megaptera novaeangliae) surfacing with barnacles encrusted on its head, Wilhelmina Bay, Antarctic Peninsula, Antarctica, January.

Solvin Zankl / Common goose barnacle (Lepas anatifera) on a piece of plastic. Sargasso Sea, Bermuda

Philippe Clement / Goose barnacles (Lepas anatifera) Aquitaine, France, May.