Saturday Science: Sea Monkeys

Hatching a tank full of Sea Monkeys is one of the most fun and rewarding science-based activities for kids and adults alike!

Saturday Science Sea Monkeys

In order to make the experience of hatching and caring for Sea Monkeys as informative and educational as possible, it’s important to understand the science behind these fascinating creatures.

This Science Saturday, we’re going to be sharing all the information you could ever need about Sea Monkeys, from their basic biology 

What Is A Sea Monkey?

Although the name ‘Sea Monkey’ might lead you to assume that this tiny creature is a type of aquatic monkey, that is not the case. In fact, the creatures advertised as Sea Monkeys are actually brine shrimp.

Hybrid brine shrimp are derived from crustaceans. Specifically, the crustaceans used are those that experience a process called cryptobiosis.

This is commonly known as suspended animation, and some creatures are able to enter this state when they are in environmental conditions that don’t meet their basic needs. 

Creatures capable of cryptobiosis are also able to sense when the conditions around them are more suited to their needs, at which point, they can reanimate themselves, which is pretty amazing!

Brine shrimp have been sold as Sea Monkeys for over 70 years at this point. They’re typically sold in hatching kits, which contain sachets of suspended-animation brine shrimp eggs. The eggs are so tiny, they look like flecks of dust.

While you won’t find Sea Monkeys specifically in nature, because they are hybrids bred for the purpose of being kept as pets, you can find other types of brine shrimp in salt water environments, including brine pools. 

Sea Monkey Growth and Development 

When they are put into water, the eggs will exit their state of cryptobiosis and become reanimated over a period of time because they recognize that they can survive in this environment. 

As the brine shrimp hatch and begin to grow, you’ll see why these animals have been nicknamed Sea Monkeys. Their tails are curled, like monkey tails.

They will have just one eye when they first hatch, although two more will develop as they mature (you’ll have to look carefully to see this). 

The bodies of the Sea Monkeys will be translucent, and if you look close up, you will notice little feathers on their feet. These fibers are what the Sea Monkeys use for respiration. 

In order to help your Sea Monkeys grow, you will need to feed them a spirulina and yeast diet, which should be included in your purchase along with the Sea Monkey eggs and the tank. 

Sea Monkeys can live for up to a year in most cases, as long as they are well cared for and kept in optimal conditions. In some exceptional circumstances, sea monkeys can survive for up to 5 years!

How To Set Up Your Sea Monkey Tank 

Saturday Science Sea Monkeys

When you purchase your Sea Monkey eggs, you should also be sent an aerated aquarium with a water filter. If not, you will need to source these yourself.

Make sure any container you purchase separately for your Sea Monkeys is clear so that you can observe your brine shrimp through the tank. 

You should also get yourself a pH meter and water thermometer so that you can make sure the temperature and pH is optimal for your Sea Monkeys’ survival. Getting some test papers for nitrogen monitoring is also a good idea. 

Most Sea Monkey sellers will also provide you with the appropriate food, but if not, you can ask your local pet store for algal paste. 

  1. Fill your tank with water and measure the pH, nitrogen, and temperature before doing anything else. Your water’s pH should be no higher than 8 and no lower than 7.5 The temperature should be between 20 degrees and 25 degrees Celsius, and the Nitrogen should not be above 320 mg/L. If you’re able to measure salinity as well, you should be aiming for about 35 mg/L.
  2. Add your brine shrimp to the water. Close the lid on the tank to avoid any accidental spillages and wait for the sea monkeys to hatch. 

Fun Science With Sea Monkeys 

Once you have added your Sea Monkey eggs to the tank, there are plenty of fun mini-experiments you can do.

None of these experiments involve handling or harming the Sea Monkeys in any way. They are just exercises in observation and will help kids to discover more about nature. 

  1. Take pictures of your brine shrimp with a smartphone or camera. You can take these photographs at regular intervals to document their growth and encourage your kids to write down or discuss their observations. 
  2. Watch the brine shrimp with a microscope. This will allow for closer observation of their anatomy and behavior. 
  3. Shine a flashlight into the tank. Your brine shrimp should follow the beam of light. See how their behavior changes again when you turn the light out. 
  4. Watch out for molting. When your brine shrimp molt, try to spot the exoskeletons.
  5. Compare your Sea Monkeys to the shrimp you can find at the store. How are their anatomies different?
  6. Try to guess how many Sea Monkeys are in the tank. Not only is this a fun guessing game, but it’s an opportunity for observation and also encourages spatial visualization, which is an important skill in science.
  7. Watch the sea monkeys feeding. Discuss what nutrients they are getting from their food and see how they eat.

Final Thoughts 

When taken care of properly, Sea Monkeys can provide kids with a whole year of scientific fun. These hybrid brine shrimp respond to different light conditions, breathe through the feathers on their feet, and molt, revealing their exoskeletons. 

You can observe your sea monkeys through a microscope or keep track of them using a camera. It’s also fun to compare their anatomy to those of other sea creatures, and watch them going about their lives. 

Remember to monitor the temperature and pH of the water in the tank, as well as the Nitrogen levels and salinity. 

Suzy Anderson
Scroll to Top