Emanuele Biggi / Mandarin Crab (Geosesarma notophorum), adult female with her spawn on the carapace, Pulau Lingga, Sumatra, Indonesia.

Ingo Arndt / Close up of Spurred tortoise (Geochelone sulcata) shell, Senegal, Africa, vulnerable species

Ingo Arndt / Shell detail of Hermann's tortoise {Testudo hermanni} France

Jeff Rotman / Lobsterman measures length of American lobster (Homarus americanus) carapace to determine if it's legal, if too large it will be returned to the sea, Portland, Maine USA October

John Cancalosi / Painted turtle (Chrysemys scripta) eating algae off the carapace of a Snapping turtle (Chelydra serpentina) Maryland, USA, August.

Solvin Zankl / Crab zoea larvae with strong and almost spherical carapace. With long and prominent rostrum pointing downwards. Atlantic Ocean off Cape Verde. Captive.

Willem Kolvoort / Aldabra Giant Tortoise (Aldabrachelys gigantea) carapace / shell detail from above, Grand Terre, Natural World Heritage Site, Aldabra

Willem Kolvoort / Aldabra Giant Tortoise (Aldabrachelys gigantea) close up of retracted head, Grand Terre, Natural World Heritage Site, Aldabra

Georgette Douwma / Green turtle (Chelonia mydas) with two remoras (Echeneis naucrates) attached to its carapace, at rest on artificial reef. Mabul, Malaysia.

Pete Oxford / Wood turtle (Glyptemys insculpta) carapace detail. Captive, occurs in North America, Endangered species.

Pete Oxford / Wood turtle (Glyptemys insculpta) carapace detail. Captive, occurs in North America, Endangered species.

Pascal Kobeh / Green turtle (Chelonia mydas) on sea floor with Remora (Echeneis naucrates) on its shell / carapace, Mayotte. Indian Ocean.