Ocean World learning pack

Ocean Secrets

Discover 4 amazing ocean creatures.

Four short discoveries about the octopus, blue whale, shark, and dolphin using the current mobile content.

Discovery 01

Octopus

The eight-armed genius of the reef

💡 An octopus has three hearts!

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Two hearts pump blue blood to its gills, and one heart pumps blood to the rest of its body.

Go deeper: When an octopus swims, the heart that serves its body actually stops beating — which is one reason octopuses prefer crawling along the seafloor instead of swimming.
Advanced: Octopus blood is blue, not red, because it carries oxygen with a copper-based molecule called hemocyanin instead of the iron-based hemoglobin found in human blood.

Discovery 02

The largest animal ever to live

💡 A blue whale's heart is as big as a small car!

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Blue whales are the largest animals to have ever lived on Earth — even bigger than the biggest dinosaurs.

Go deeper: Its heart alone can weigh as much as a small car, and just one beat can travel for miles through the deep ocean.
Advanced: A blue whale's tongue can weigh as much as an elephant, and during feeding season it can eat several tons of tiny shrimp-like krill in a single day.

Discovery 03

Older than trees, faster than fear

💡 Sharks have been swimming in our oceans longer than trees have existed on land!

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Sharks appeared over 400 million years ago — way before the dinosaurs.

Go deeper: Most sharks also never stop growing new teeth — a single shark can go through thousands of teeth over its lifetime.
Advanced: Sharks don't have any bones at all — their entire skeleton is made of cartilage, the same bendy material as your ears and nose.

Discovery 04

The ocean’s clever chatterbox

💡 Dolphins call each other by name!

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Every dolphin makes its own special whistle sound, kind of like a name, so other dolphins know exactly who is calling.

Go deeper: Dolphins also sleep with only half of their brain at a time, so they can keep breathing and watch for danger while they rest.
Advanced: Scientists believe dolphins can recognize themselves in a mirror — a rare sign of self-awareness shared by very few animals on Earth.