Solvin Zankl / As soon as it enters the water the young Olive sea turtle (Lepidochelys olivacea) struggles against the swell to swim away from the coast. Pacific coast, Costa Rica, October. ^^^This swimming frenzy...

Solvin Zankl / As soon as it enters the water the young Olive sea turtle (Lepidochelys olivacea) struggles against the swell to swim away from the coast. Pacific coast, Costa Rica, October ^^^ This swimming frenzy...

Michael D. Kern / California gull (Larus californicus) predating an egg, San Francisco Bay, USA, SFBBO Gull Count SFBBO Gull Count, May 2009

Tim Laman / Antarctic / Subantarctic / Brown skua (Stercorarius antarcticus) feeding on Gentoo penguin egg, Antarctica, January

Tim Laman / Antarctic / Subantarctic / Brown skua (Stercorarius antarcticus) feeding on Gentoo penguin egg, Antarctica, January

Jeff Rotman / Newborn Spiny Pygmy Shark (Squaliolus laticaudus) with yolk sac still attached held in hand, Israel, Mediterranean Sea.

Wild Wonders of Europe / Roggo / European grayling (Thymallus thymallus) alevins, 1 day old, with yolk sacs, from Lake Thun, Switzerland, captive, April 2009

Ingo Arndt / Amu-Darya Trout (Salmo trutta trutta) alevin freshly hatched with full yolk sac, Europe

Ingo Arndt / Amu-Darya Trout (Salmo trutta trutta) egg with alevin already visible through egg-shell, Europe

Warwick Sloss / Weedy sea dragons (Phyllopteryx taeniolatus) babies, with yolk sacs still visible, wild-caught but filmed in captive conditions under licence, from the coast around south Australia

Warwick Sloss / Weedy sea dragons (Phyllopteryx taeniolatus) babies, with yolk sacs still visible, wild-caught but filmed in captive conditions under licence, from the coast around south Australia

Jeff Rotman / Premature Great blue shark (Prionace glauca) with yolk sac placenta, New England, USA