Penguin foetus. Coloured scanning electron micrograph (SEM) of a Gentoo penguin (Pygoscelis Papua) foetus at eighteen days incubation. The gentoo penguin is a medium-sized species of penguin that is found on the rocky islands of the sub-Antarctic Ocean. Gentoo penguins are most easily distinguished by the white "bonnet-like" marking across the top of their heads, and are most closely related to the Adelie and Chinstrap penguins which belong to the same group. Magnification: x5 when printed 10cm wide.