Nick Upton / Crumb-of-bread sponge (Hymeniacidon perlevis), orange encrusting form on exposed intertidal rocks. Recent growth pattern visible. Cornwall, England, UK. September.

Nick Upton / Crumb-of-bread sponge (Hymeniacidon perlevis) in orange encrusting form. Exposed intertidal rocks, Cornwall, UK. September.

Nick Upton / Dog whelk (Nucella lapillus) egg capsules surrounded by a mat of Crumb-of-bread sponge (Hymeniacidon perlevis) on exposed intertidal rocks, Cornwall, UK, April.

Nick Upton / Crumb-of-bread sponge (Hymeniacidon perlevis) in encrusting form showing colour variation from orange to green on exposed intertidal rocks, Cornwall, UK, April.

Nick Upton / Crumb-of-bread sponge (Hymeniacidon perlevis) in its bright orange encrusting form on exposed intertidal rocks, Cornwall, UK, April.

Sue Daly / Breadcrumb Sponge (Halichondria panicea) on the seashore, Guernsey, British Channel Islands.

Norbert Wu / Polychaete (Isodictya erinacea) group and diver with grounded iceberg, Antarctica

Norbert Wu / Emerald Notothen (Trematomus bernacchii) on Polychaete (Isodictya erinacea) notothenioid fish uses antifreeze glycoproteins to keep from freezing in Antarctic water, Antarctica

Fred Bavendam / Sponge (Isodictya sp) group underwater, Halfway Rock, Glouchester, Massachusetts

Alex Mustard / Velvet swimming crab (Necora puber) crawling across a bright yellow Breadcrumb sponge (Halichondria panicea) on the wreck of the Rosalie, Weybourne, Norfolk, England, UK, North Sea.

Robert Thompson / Crumb-of-bread sponge (Hymeniacidon perlevis) exposed on rocks at low tide, Greyabbey Bay, Strangford Lough, County Down, Northern Ireland. July.

Alex Mustard / Sponge spider crab / Decorator crab (Inachus sp) on Sea vases (Ciona intstinalis). Kinlochbervie, Sutherland, The Highlands, Scotland, United Kingdom. Loch Inchard, The Minch, North East Atlantic Ocea...