Sea monkey

Sea Monkeys are a type of brine shrimp, and a member of the animal family Crustacea, which also includes crabs and lobsters. All crustaceans have a hard shell (known as an exoskeleton) that provides their bodies with support, the way our bones help us keep our shapes. Having a hard shell is great when you’re a small creature in a big ocean! It makes it more difficult for animals to eat the Sea Monkey and get to its gooey parts inside. But there’s a big problem. As the Sea Monkey grows bigger inside the shell, the shell stays the same size. So it needs to shed its shell, but this exposes its soft bodies to the outside world. It’s a perfect time for predators to eat them! (Fortunately, Sea Monkeys don’t have any predators in the little tank, so yours will be safe!) So they want to grow that shell quickly. Once the shell grows back, larger and harder, they are protected until the next time they need to grow bigger!
Sea Monkeys can manufacture their own trehalose, a substance they use to coat their eggs to keep them safe from extreme temperatures and lack of water. Once coated, these eggs are now called cysts and they can live many years in this state. But once the conditions are just right and you add the water to the eggs, they come back to life! This is how Sea Monkeys appear to come instantly to life when you add water!
The males are always smaller than the females (although this doesn’t help if you don’t have any females to use as a comparison!) And if you look closely, you’ll see that the males have pincers coming from under their chins. They use these pincers the way crabs or lobster use their claws, to fight or grab things. The females are generally larger, and once mature, will carry a brown coloured egg sac on their stomachs.

Did you know that when Sea Monkeys are born, they have three eyes? And as they get older and closer to adulthood, they lose that middle eye? (And you’d think that something like that would come in handy!) This is one way to tell when they are full grown, although it is hard to see the third eye. There are other, easier ways to tell when Sea Monkeys are mature. First, they grow bigger — up to 3/4 of an inch long! Second, the males will grow pincers under their chins. Third, you will see an egg sac on the stomach of the female. And finally they will have moulted their shells quite a number of times. If you look on the bottom of the tank, you might see some black things that look like Sea Monkeys. These are discarded shells. Can you tell when they are moulting? It’s hard, but if you watch carefully, you may see them shedding their shells!

Sea Monkeys don’t have brains; they have groupings of nerves called “ganglia.” One of these is found in the Sea Monkey’s head, the other just below the gut. These ganglia send out the messages to the Sea Monkey’s body to do different things, such as eat, or sleep, or chase after another Sea Monkey.

They breathe through their legs, using long tubes that come up from their feet. The gill plates along the sides of their legs help transport the oxygen they need to live! This is why they are called “branchiopods”.

A Sea Monkey’s kidneys aren’t located in its abdomen, the way ours are. Its kidneys are located in its head!

Sea Monkeys have a circulatory system to help move the blood around their bodies. Their hearts, located dorsally in their torsos, pump blood around their tiny bodies, the way our blood is pumped through our circulatory systems. As a note, they have hemoglobin in their blood, as do we. Hemoglobin helps carry oxygen around the body. Strangely, there is an inverse correlation between the amount of oxygen in a Sea Monkey's blood and the outside environment; the more oxygen in the tank, the less in the blood, and vice versa.

Sea Monkeys sometimes appear to be juggling the algae in the tank. Why is this? They are using their little legs to push the algae up to their mouth parts so they can eat it. And sometimes the Sea Monkey will look red. This is because the blue-green algae sometimes metabolizes their bodies to make it appear an orangy colour.