Sea Monkeys

Brine Shrimp (Artemia salina) aka Sea Monkeys

One of my favourite “pets” when I was smaller was a tank full of Sea Monkeys. Little did I know at the time, but they are actually brine shrimp that are used to feed juvenile fish at the Salish Sea aquarium (and other aquariums around the world). 

The Amazing LIVE Sea Monkeys!!

These tiny shrimp survive by living in high salinity environments (usually over 60%) because predators cannot handle such an extreme environment. The real brine shrimp do not resemble the comic book version of Sea Monkeys with their pot bellies, webbed feet and crowned heads but instead look like prehistoric, skeletal shrimp with 19 segments comprising their body and the last few segments making a tail. Males grow to about 8 – 10 mm, females grow to 10-12 mm, and both are about 4 mm in width. An interesting fact is that adult brine shrimp have three eyes! They start with a median eye located on the centre of their head, and then as an adult, they develop two more compound eyes mounted on flexible stalks. 
 
Adult Brine Shrimp have three eyes!

Adult females ovulate about every 140 hours and under normal conditions their eggs will hatch right away. The coolest thing about these small critters is that if the salinity drops drastically or their water source dries up, the female’s eggs become dormant and will remain in suspended animation for several years until conditions improve! These dormant eggs, called cysts, have a tough brown-coloured chorion coating and they remain metabolically inactive in a state called cryptobiosis, meaning “hidden life.” If the cysts are then placed in salt water they can hatch within a couple of hours! This is why artemia are perfect as a food source for aquariums where dried cysts can be received and kept dry and cool until ready to be used. 

The commercial industry collects cysts from salt lakes and salt flats to be sold to aquariums and research facilities around the world. Only a small number of companies are allowed to harvest eggs every year. They use spotter planes, GPS, and night vision technology to find “slicks” or floating mats of reddish-brown eggs. A boom is used to surround the eggs and then suck them into sacks on the boat, and they are eventually washed, dried, and vacuum-sealed for shipment.
At the Salish Sea aquarium, the cysts are bleached to make the protective chorion coating thinner so that the larvae can hatch without using as much energy while still retaining a lot of the nutritional value of their yolk sacs. At the aquarium, dried cysts are added to a tower of briny/salt water heated to 30 degrees Celsius, and within 24 hours, the first stage of life called nauplii emerge. The nauplii are then transferred to another tower to go through a process called gut loading for another 24 hours of development. During gut loading, they feed on mixtures of fatty acids and amino acids so that they can pass on benefitial nutrition to the next animal up the food chain. Some artemia are also kept to grow to full size (after three weeks) to feed to juvenile fish. 

Who knew brine shrimp could be so versatile? Did you know that in 1998 approximately 400 million cysts were flown to the moon and back for scientific research? Apparently cosmic radiation is not good for them!


http://mentalfloss.com/article/56755/16-amazing-facts-about-sea-monkeys

https://en.wikipedia.org/wiki/Brine_shrimp