Imagine being a tiny crustacean, barely a millimeter in size. In a world where every fish looks like a giant monster, life becomes a constant race to avoid ending up in someone's jaws. Water fleas, scientifically known as Daphnia , have had to devise ingenious ways to survive, developing tricks that would put any secret agent to shame.
Evasion tactics and the art of chemical espionage
To avoid becoming anyone's lunch, Daphnia have implemented a daily transportation system. During the day, when the light is intense and the fish are most active, they remain in the deepest, darkest layers of the water. Only when night falls do they dare to rise to the surface to feast on algae, making vertical journeys of up to 60 meters each day.
Physical mutations to survive the attack
In the case of Daphnia pulex , the struggle is constant against the larvae of the fly Chaoborus. These larvae emit pheromones that the Daphnia juveniles recognize, responding by developing "neck teeth ," which are sharp protuberances that appear during the next molt of their exoskeleton. Although this saves their lives, it comes at a cost: their development period is considerably lengthened.
The science behind chemical receptors
Anatomy and curiosities of these crustaceans
- Uses in aquariums: They are a Excellent live food for fish.
- Ecological indicators: Its disappearance usually indicates that the water is contaminated.
- Types: There are herbivorous species (fresh and salt) and carnivorous species (marine), the latter being the ones that can cause itching when we bathe at the beach.
