🐠 Sea creatures big and small

Yes, wiggle your body side to side like a fish tail and pretend to swim across the floor.

Fins help a fish push against the water to swim forward, and different fins do different jobs, some push the fish ahead while others help it steer left or right and stay balanced without rolling over. The tail fin usually does most of the pushing, swishing side to side to drive the fish through the water, while fins along the fish's sides and belly work more like tiny rudders and stabilisers. Without fins, a fish would have a hard time controlling which way it faces or moving anywhere on purpose, and it would likely tumble around in the current instead.

Dolphins are actually not fish at all, they are mammals, just like people, which means they cannot breathe underwater and must swim up to the surface regularly to breathe air through a blowhole on top of their head. A dolphin can hold its breath for several minutes at a time while diving and hunting, then returns to the surface, takes a quick, powerful breath, and dives back down again. Because breathing takes conscious effort for a dolphin, unlike for humans, dolphins actually sleep with only half their brain resting at a time, so the other half can keep them swimming up for air.

A dolphin makes clicking and squeaking sounds to talk to other dolphins underwater.

A whale is one of the biggest sea animals, so big that a whole class of children could stand on its back.

A jellyfish is almost entirely made of water, with hardly any solid parts inside. That lets light pass straight through its body instead of bouncing off, the way light does with animals that have solid bodies. Being mostly transparent also helps a jellyfish hide from predators and sneak up on the tiny creatures it eats, since it can drift through open water without standing out clearly against its surroundings. Even though jellyfish look soft and simple, they have been drifting through Earth's oceans for an incredibly long time, long before most other animals even existed.

Yes, snap your thumb and fingers together like a little claw, just like a crab does to grab its food.

Most starfish grow with their arms spreading out evenly around a middle point, kind of like the shape of a star. Five arms just happens to be the most common number for many starfish species. Each arm is actually packed with its own set of tiny tube feet underneath, which the starfish uses together to slowly grip and pull itself along the seafloor. If a starfish loses an arm to a predator, many species can slowly regrow a brand new one over time, and in some species, a single lost arm can even grow into an entirely new starfish.