The Secret Life of Bugs:

Water Fleas vs
Water Mites

A case of mistaken identity
by Natalie Walton, Aquafix Microscopist

In short, no; water fleas and water mites are not interchangeable terms for the same organism. Both, however, are nicknames for two different organisms. In fact, you may even recognize the genus name of water fleas, daphnia, as they are used in effluent WET testing. Water mites, on the other hand, are not as likely to be recognized by their scientific name, Hydrachnidia, because there are over 6,000 known species and they only occasionally appear in wastewater plants. While daphnia are also not usually frequent fliers in wastewater, they tend to be more well known than water mites. That’s why this blog will focus more on water mites than water fleas. However, if you came here just for the water fleas and don’t care about the mites, you can check out the daphnia exposé in our microorganism database here . Now, join me as I shed some light on water mites.

Water mites, as mentioned before, are very diverse and come in a wide range of colors. They, like daphnia, typically do not cause issues within a wastewater system. In my experience, the only harm water mites cause is their ability to make one shudder in discomfort due to their close resemblance to spiders. In fact, water mites are more closely related to spiders and humans than the other higher life forms found in wastewater. To feed, these pseudo-spiders channel their inner vampire and bite their prey. This bite injects enzymes that liquefy the insides of its victim, which then get sucked out. Some of their unlucky prey include smaller water mites, nematodes, and rotifers. Luckily for us humans, we don’t make this list

The cause of water mites in wastewater is not very well known. They are thought to appear in systems that are healthy but have a high sludge retention time. Hopefully, as time goes on more research will be conducted to better understand these creepy crawlies and their relation to wastewater systems.

Thanks for reading and stay tuned for the next edition of Secret Life of Bugs.

Have something under the microscope you don’t quite understand? Try our Microanalysis and Filament Origins Test Kit to get a comprehensive view of what is happening in your plant.

About the Author

Natalie Walton joined Aquafix in 2019 and focuses on performing microscopic analysis for customer samples, as well as conducting experiments on innovation in grease removal. She was also a key contributor to creating our Microorganisms Database supplying identification tips and research.