Just Another Day (A Guest Post)

By Cassie Apostolou

The zooplankton picture on the left was provided by the EPA at Wikimedia Commons.
The human picture on the right was provided by Cassie Apostolou.

Check out the two pictures above. It doesn’t look like those two animals share a lot in common, right? Obviously the two organisms don’t look alike and the zooplankton (the odd looking microorganism creature in the left picture) lives in water and us humans typically like to stay dry on land. But if you dig a little deeper than just what you see, you’ll notice that most humans (probably you too) tend to endure specific daily migration patterns just as these little creatures do as well. Curious? Or maybe even offended that I pretty much just compared you to a zooplankton? Then continue reading and obtain the information you can throw in a friend’s face next time they are on an ego trip!

Whether you are in school or have a job, I’m sure you have a daily schedule you stick to. A daily example most people can relate to is this: you wake up to the annoying beeping of your alarm, maybe take a shower, change clothes, eat some breakfast, and then are headed off to work or school, you stay there for so many hours and then turn around and head on home (probably even taking the same routes most days too!) Well, as we do this on a daily basis, many zooplankton have a regular schedule too.


Photo of drifting zooplankton by
NOAA at Wikimedia Commons.

Zooplankton means “animal/water drifters”. Most get this name from performing daily vertical migrations cycles by floating or swimming to the surfaces of waters at night, while during the day time they stay in deeper depths of the waters. Why do they do this though? Well, research has shown that some zooplankton perform these daily cycles to escape fish predators and to obtain their food source. Also, daily migration occurs for the prevention of solar damage (just like humans and sunburn). There is also current research testing if metabolic advantages are also a cause for these migration patterns. Furthermore, studies have looked into external changes (such as temperature, salinity, and even acidity changes) as being a reason.

Photo of zooplankton under the microscope
by Ma.C. Mingorance Rodriguez at Wikimedia.

How do these animals with hardly any external features perform these day-to-day migrations? These creatures have to be in good physical shape to out-swim the predators. Also, they have to be able to adapt to the changing temperatures due to the sun or even the temperature changes in their environment. Plus, they have to be able to swim within a large group of other zooplankton to push against the ocean factors. Lastly, the zooplankton that perform the daily migrations are physically able to do so because some have evolved a pseudopodia (aka “false feet”) or flagella (tail like structure) adaption to help them move.

Still think you are way different than a zooplankton? Well, don’t you return to a safe area at the end of the night? I’m sure you eat at certain times and not at others and the food you get is mainly from the same places (probably your refrigerator or favorite restaurant). So in the end aren’t we all just walking around to obtain the necessities we need in life, just like zooplankton? I think when it comes down to the basics yes, but humans have put their own twists on life too.


References:

1. Forward, R.B. Diel Vertical Migration: Zooplankton Photobiology and Behaviour. in Oceanography and Marine Biology Vol. 26, ed. H. Barnes and M. Barnes, Aberdeen University Press, 1988, 361- 393.

2. Haney, J.F. (1988). Diel Patterns of Zooplankton Behavior Bulletin of Marine Science, 43 (3), 583-603

3. Iwasa, Y (1982). Vertical Migration of Zooplankton: A Game Between Predator and Prey The American Naturalist, 120 (2), 171-180 DOI: 10.1086/283980