Original Wild Facts

Wild Fact #844 – Not Your Typical “Zoo” Animal – Daphnia

Photo: Paul Hebert

I am going to issue a warning before getting into the details of today’s Wild Fact.  If you love swimming in lakes or perhaps like drinking fresh lake water while camping then you may want to skip today’s fact.  Still here?  Well that is great because we are going learn about one of the many types of zoo-plankton that can be found in lakes, ponds, streams and rivers.  This particular fact is about the ever popular, Daphnia.

Daphnia are also called “water fleas” although they are not closely related to fleas or insects for that matter.  Daphnia are actually crustaceans.  Yes just like lobster and crabs.  Okay, maybe not just like them but the same taxonomic group.  These water fleas tend to be anywhere between 0.2 – 5 mm (0.008 – 0.2″) long and can be found just about any place that has water.

Just because these “fleas” are tiny does not mean they are not important to the ecosystem.  The majority of Daphnia are filter feeders which means they will actually clean the lakes by feeding on algae and bacteria. As well, they provide a valuable service to larger members of the food chain such as fish.  Unfortunately, they have to sacrifice their life to provide this important service to the ecosystem.

I understand that it is difficult to see Daphnia as animals since they are tiny and mysterious but the truth is they aren’t that different from other animals. They have legs, antennae, eyes and even a nervous system.  In fact, scientists often study Daphnia to assess the effects of depressants on the nervous system.  They are a great resource since they are clear which allows you to actually see the heart-rate. I wonder if a Daphnia has ever won the Nobel Prize for their research work?  Nah, probably not!

Before we end today’s fact, I just want you to think that it is possible to have as many as 100 000 of these “water fleas” per cubic meter in the Great Lakes.  Even more astonishing is this is only one type of zoo-plankton!  There are many more which are even tinier.  This might make you think twice before you take that big gulp of fresh lake water.

Enjoy the rest of your day!

4 Comments

  1. I’m always so impressed by the quality of the photos on your blog! I had no idea that zoo-plankton could look so beautiful. Great job Nathan, keep up the fun facts and the wonderful photography!

    1. Hi Amanda,

      Thanks for the compliments and for stopping by Wild Facts today.

      There are a lot of interesting looks to zoo-plankton but they are definitely an fun looking animal.

  2. I have mixed feelings about this creature. Unlike humans, I have no issues with drinking microscopic, or near-microscopic animals in my water – they are an extra added source of protein! But, uh, anything called a “flea” immediately turns me off. Eating these things won’t give me tapeworms, will it?

    1. There sure does seem to be a lot of animals nicknamed after the Flea. I had never thought of zoo-plankton providing protein before. That is a great way to look at it!

      I think you are safe to eat zoo-plankton, Sparkle. They are fairly harmless and shouldn’t be feared.

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