Tiny helper aka: Daphnia otherwise known as the water flea. Photo by: Micropia, n.d

Here in the Conservation Corner at the Greater Vancouver Zoo, a team of Wildlife Preservation Canada staff run three conservation breeding programs simultaneously. The focus species of these endangered species recovery programs are the Taylor’s checkerspot butterfly, the western painted turtle and the Oregon spotted frog. While these are the main characters of our breeding programs, they are not the stars of this blog (heavy-handed foreshadowing). Taking care of three endangered species is busy work.

That’s why we take whatever help we can get.

Caring for amphibians means lots of cleaning. In the Conservation Corner there are a gridwork of tanks. This is where we keep our Oregon spotted frog tadpoles and adults. We feed our tadpoles blended up green vegetables. Not to say that tadpoles are messy eaters, but much of their veggies end up at the bottom of the tank. We do our best to clean most of this up, but what waste is left behind promotes growth of algae which pollutes the tanks, which we manage by changing the water in the tanks. Water changes are a necessary part of keeping any aquatic species, but it takes time and effort.

Come check out the Conservation Corner at the Greater Vancouver Zoo. Photo: M. Gardiner

A bucket-full of Oregon Spotted Frog tadpoles ready for release, above. And below, a single tadpole, a very messy eater. Photos: M. Gardiner

Luckily, in any given tadpole tub you can find hundreds of WPC volunteers, Daphnia. Daphnia or waterfleas, are tiny crustaceans which exist in any healthy freshwater ecosystem [1]. They help our breeding programs by cleaning our tadpole and frog tanks for us. While Lead Biologist Andrea jokes that Daphnia should be added to the payroll, they are happy to help for free. This is because Daphnia feed on algae, bacteria and other microscopic particles in water [1]. They act as little pool-filters sucking out the things which dirty-up the tanks in Conservation Corner.

The star of this article. Photo by: P. Hebert

While daphnia may be small, their impact on water clarity is not. I was inspired to write this article when I saw their influence first hand. Noticing one of the unoccupied tadpole tanks was looking a little green, Andrea skimmed a school of daphnia from a clearer tank and transferred them over. The results were quickly noticeable. The next morning the tanks was already cleaner. A week later and the tank was completely transparent.

Skimming daphnia to spread the love, above. And below, before and after adding daphnia to the tank. Photo by M. Gardiner

Being that they are such important team members, I figure Daphnia deserve their time in the spotlight. Here are some facts that will acquaint you with this tiny crustacean:

  • Daphnia get their colour from their diet. Green or transparent Daphnia, feed primarily on algae, while red or pink individuals feed on bacteria(Ebert, 2005).
  • They are able to take on massive workloads because they reproduce rapidly. During their 2 month lifecycle, Daphnia can produce eggs approximately twice per week(Ebert, 2005).
  • Since Daphnia are so numerous, they are commonly used as a study subject for scientists. They are responsible for advances in genetics, evolution and ecology(Altshuler, et al., 2011).
  • Being filters of all things microscopic, Daphnia are often used to detect pollutants in water(Altshuler, et al., 2011).

Daphnia really are amazing and helpful little creatures. If there was an award for smallest creature with the biggest work effort, I would nominate Daphnia.
On behalf of the Conservation Corner Crew, thank you Daphnia.


Altshuler, I., Demiri, B., Xu, S., Constantin, A., Yan, N. D., & Cristescu, M. E. (2011). An Integrated Multi-Disciplinary Approach for Studying Multiple Stressors in Freshwater Ecosystems: Daphnia as a Model Organism. Integrative and Comparative Biology, 51(4), 623-633.

Ebert, D. (2005). Ecology, Epidemiology, and Evolution of Parasitism in Daphnia. Bethesda: National Center for Biotechnology Information (US).

Micropia. (n.d.). Artis Micropia. Retrieved May 20, 2022, from https://www.micropia.nl/en/discover/microbiology/water-flea/

Image References

Hebert, P. (2005). Daphnia pulex. [Photo]. Wikipedia. Retrieved from: https://en.wikipedia.org/wiki/Daphnia#/media/File:Daphnia_pulex.png

Micropia. (n.d.). Water flea. [Photo]. Micropia. Retrieved from: https://www.micropia.nl/en/discover/microbiology/water-flea/

Mitchell Gardiner

Lead Butterfly Technician – Taylor’s Checkerspot Butterfly Recovery

Mitch recently attained a Bachelor of Science at Trent University where he majored in Conservation Biology.

Past experience in tallgrass prairie stewardship, and an interest in lepidoptery has given Mitch the opportunity to work closely with endangered butterflies. He previously worked on the Mottled Duskywing Reintroduction project, and is hoping to transfer expertise to the Taylor’s Checkerspot Recovery.

Mitch enjoys learning about new species, and meeting their respective experts. What he appreciates most about conservation is fostering a passion and respect for nature in others.