Hobotnica i njezina tri srca

Hobotnica je meka životinja koja živi u moru. Ima osam krakova i nema kosti. Ali najiznenađujuća stvar je unutar njezinog tijela. Hobotnica ima tri srca, ne jedno.

The octopus is a soft animal that lives in the sea. It has eight arms and no bones. But the most surprising thing is inside its body. The octopus has three hearts, not one.

Dva srca tjeraju krv prema škrgama. Ondje krv iz vode uzima kisik. Treće srce zatim šalje tu krv u ostatak tijela, tako da hobotnica ima energiju za kretanje.

Two of the hearts push blood to the gills. There the blood takes in oxygen from the water. The third heart then sends this blood to the rest of the body, so the octopus has energy to move.

Krv hobotnice je plava, ne crvena. Plava je jer sadrži bakar. Ova posebna krv pomaže hobotnici živjeti u hladnoj, dubokoj vodi. Kad hobotnica pliva, njezino glavno srce prestane raditi, pa radije hoda po morskom dnu.

The blood of an octopus is blue, not red. It is blue because it has copper inside. This special blood helps the octopus live in cold, deep water. When the octopus swims, its main heart stops, so it likes to walk on the sea floor instead.