Scientists have discovered a miniature crustacean, known as a water flea, that can grow its own armor to defend itself. Even better — the armor is customized for each enemy.
As the Daphnia species grow and mature, they develop tail spines, neck spikes, and helmets based on the chemistry of their aquatic environments.
These miniature creatures will molt once they mature, and their adult exoskeleton will be molded to the specifications of the chemicals left by predators, such as a certain fish or insect, in the water around them. Each Daphnia can detect these scents with appendages called antennules.
Weiss explained that Daphnia will design their exoskeletons in a way that makes it difficult for their predators to eat them: “These defenses are speculated to act like an anti-lock key system, which means that they somehow interfere with the predator’s feeding apparatus. Many freshwater fish can only eat small prey. So, for example, Daphnia lumholtzi grows head and tail spines to make eating them more difficult.”
This would be a great superpower.
Weiss notes the importance of this finding, suggesting that Daphnia’s varying appearances could act as a sort of “canary in the coal mine,” alerting us to changes in the water’s chemical composition.
Watch an unadorned resting Daphnia’s heartbeat under microscope here:
