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A close-up of shark skin<\/p><\/div>\n

Shark skin feels like sandpaper because it has small rough placoid scales (also known as dermal denticles). As a result, it is often dried and used as a leather product or sandpaper. Placoid scales consist of a basal bony plate buried within the skin and a raised portion that is exposed. Dermal denticles are homologous in structure to teeth, and are what gives the skin a rough feeling.<\/p>\n

Dermal denticles, as seen in this image taken from the dorsal fin of a porbeagle shark, are small tooth-like structures on the skin which form a protective barrier and aid in swimming.<\/p>\n

Magnified images of porbeagle and spiny dogfish dermal denticles taken by scanning electron microscope. Images courtesy of Frank Thomas, MicroAnalysis Facility, GSC Atlantic.<\/p>\n

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