Trout Camouflage Illustration Activity Full of Imagination

Students at Cayuga Heights Elementary School had some creative ideas when illustrating a trout camouflaging into a habitat they imagined. One student imagined there were buildings around the creek with graffiti on the walls, so they used the Disruptive Camouflage method of creating a pattern on the trout that mimicked the graffiti. 

Other students imagined more natural habitats, like a sand-bottom creek in the fall time, illustrating this with lots of yellow and red tones on their trout as it tries to blend in to the colors in its environment. Some kids were in the holiday spirit and created their trout based on holiday-related themes. One student, for example, imagined her trout in a candy land environment, and illustrated this with many vibrant colors on the trout to conceal within its surroundings.

Students were told to close their eyes and imagine a place where a stream could be, they were told to be as imaginative and creative as they wanted. Their goal was to illustrate a trout that lives in this steam and to utilize one of the three camouflage methods- Concealing, Disruptive of Countershading- to help the trout blend into their surroundings. By blending in, and using different camouflage methods to change their appearance, trout have more chances of survival, like sneaking up on prey and hiding from predators. This is especially important in young trout, who are still developing and gaining the strength and instincts to survive. That's why black markings, or "parr marks" are found on young trout but not on adults. Parr marks are a form of Disruptive Camouflage, they create a sense of confusion or distraction to prey and predators. When a school of trout with parr marks swim by, the markings make it very distracting to be able to tell one trout apart from another, especially with the addition of water movement and sunlight. All this is a natural adaption trout have gained over time to be able to survive in their environment.

Students across all schools seemed to really enjoy this camouflage activity and made many great observations about other animals in the wild that use types of camouflage for survival techniques. As the trout continue to grow in the Fry or Parr stage, these colorings and markings will become even more noticeable and quite the fascinating spectacle to appreciate, especially with the new understanding of the natural purpose behind their appearance.

 

How do trout change color?

As we've been coming around to classes this December to talk about adaptations, or a trait that helps an organism survive, we've been talking about camouflage methods as a way for animals to adapt to their environment and noticing colors and markings forming on the trout in our tanks. But as we notice parr marks forming on the lateral line of our brook and brown trout, it's interesting to think about how the trout actually change colors.

Many fish, along with reptiles and amphibians, use cells called chromatosomes to alter their appearance. Pigment granules within each chromatosome can be constricted, or pressured, causing the granules to spread out and become more visible. All the colors found in fresh water fish are made up of three pigments, Eyrthrin (red), Melanin (black) and Xanthin (yellow), each occurring in different chromatosomes. All the colors found in freshwater fish like trout, are a mixture of these pigments created a marking or colouring on the fish- like black and yellow chromatosomes coming together to make brown coloring on the trout. 

As we watch the trout in the fry or parr stage, continue to observe as the colors and patterns become even more visible and keep in mind the scientific process creating these fascinating colors that are simultaneously beautiful to look at and useful for camouflage strategies.

Feeding Your Trout

 Now that your Parr Trout are out and swimming, they'll need feeding.  Here's an old favorite of ours...

 

LIVE Trout Cam!

Here's a great way to check in on the growth of our trout!  Introducing the Groton 4th Grade "Think Tank", full of brown trout fry, cared for by Dick Brecht's classes.  (Click to open the video, or click here for the most up to date stream)

Groton Trout Cam!

We look forward to helping more of our participating classrooms take their trout online this year.  Stay tuned....