What would your trout would be doing in the wild right now?

We've been observing our trout hunting and eating zooplankton in captivity, but what about all the baby trout in the wild? Will they have the upper fin in hunting and competing for food when we release our captive trout? Is a winter stream environment a nurturing habitat for baby trout? Let's find out!

A baby wild trout has about 4 months of life in its stream habitat by this time in February and is known as a trout "fry" or "parr." Check out this cool video to see what a brook trout parr looks like at this time of year!

Here are some cool facts about wild trout parrs and how they grow up: 

1. A wild trout parr will be smaller than a trout parr raised in captivity. This is because growing up in the wild is typically colder than growing up in a tank, the water can even be a temperature that would normally cause water to freeze if the stream is running fast enough! The colder the water a trout grows up in, the slower the trout will grow. 
   

2. 

   Stonefly larvae in June 2020.

   A wild trout parr starts hunting almost right away as soon as it can swim, and sometimes even before it can swim! While our captive trout learn to come up to the surface of the tank and beg for food, a wild trout looks for its food at the BOTTOM of a stream. This is called BENTHIC feeding and means that trout grow up mostly eating stonefly, mayfly, and caddisfly larvae that can be found hiding among the rocks of healthy streams. 
   
3. A wild trout parr will hunt and eat zooplankton, just like we watched with our captive trout in our recent feeding experiments! Wild parrs don't typically eat Daphnia (the zooplankton we fed our trout), but they do eat a different species of zooplankton... known as copepods. In fact, a common copepod that trout like to eat is called a calanoid and might look like a Plankton you've seen before (hint: Spongebob).
   

   

   Calanoid, a microscopic zooplankton.

So what do you think? Who has the upper fin? A trout that has grown up hunting and spent its whole life in the wild, or a larger trout that doesn't have as much experience hunting or hiding among the rocks? 

-Originally posted by Marina Howard, March 17, 2021