Daphnia

Identification

• Reddish-pink color
• Flea-shaped
• Macroscopically appear oval-shaped

Why Do I have It?

• Low available BOD
• Low levels of ammonia
• Suspended bacteria and algae present

Treatment

Daphnia is an indicator of a healthy wastewater plant and treatment is not typically required. If your plant is experiencing TSS issues, contact a technical rep for information and recommendations.

Under the Microscope and in Your Plant

Daphnia, commonly referred to as water fleas, are small crustaceans closely related to shrimp. They prefer water temperatures between 18-21°C (65-70°F), as well as fall or spring sunlight. These one-eyed crustaceans consume yeast, algae, bacteria, and protozoa. The most optimal temperature for their breeding is 21°C (70°F). Daphnia’s eggs can lie dormant for decades and scientists have used these eggs to see how Daphnia have evolved over time. Daphnia produce hemoglobin, causing their reddish-pink appearance. They will turn more pinkish in color if dissolved oxygen levels decrease. When present in abundance in final clarifiers or polishing lagoons, Daphnia will form pink clouds. They are typically used for whole effluent toxicity testing; their ability to thrive in a final clarifier is an indicator of an effective wastewater treatment process. The presence of Daphnia does not always indicate an issue occurring within the wastewater system, however, there are rare instances when an overabundance of Daphnia can cause high effluent TSS.

Interesting Facts

• Daphnia were the first crustacean to have their genome sequenced and it was discovered that humans and Daphnia share many of the same genes