Fish Charged for First Degree Murder

What comes to mind when you hear the word “Killerfish”? Hmm… doesn’t that seem like an odd question? Yeah, I thought that too. So I will answer first, then you can.

When I hear the word “killer fish”, I think undefeatable. I say this because I believe they are like the king of the ocean. They have different methods they use to get across the ocean and navigate to their desire destination. Hopefully, their destination won’t cause them to kill much of the ocean friends on the way. Let’s talk about one unique killerfish: Mummichogs (Fundulus heteroclitus; Cyprinodontiformes). These species have unique capabilities where it can do both: breathe air and move around on land (Bressman et al., 2016). Crazy right? These fishes have been an important part of scientist investigation and several experiments have been done to learn more about these species. In fact, I will share some important observations that I found about these species from a paper I was reading: “Look Before You Leap: Visual Navigation and Terrestrial Locomotion of the Intertidal Killifish : Fundulus heteroclitus”.

First off let’s talk about where these fishes are found. They are a widespread species that are found in” intertidal habitats, including marshes, sandbars, and rocky tidepools along the Atlantic coast of North America, from Nova Scotia to Georgia” (Bressman et al., 2016). Remember how I mentioned these fishes can locomote land? Well, these fishes are able to override the challenges that many of their peers face. They use a method of tail flip jump that allows them to move on land, unlike their peers. Fantastic, right?

Scientists wanted to learn more about this also, so they organized experiments where they placed minnow traps to collect around 30 mummichogs and kept them at a sea table with flowing seawater that was pumped around the marine station before they began the experiment (Bressman et al.,2016). Researchers tracked the paths and movements of these fishes after they laid them on a platform and gave them 5 minutes to move around freely.

What they found was that the mummichogs held themselves vertically, during each jump, where they directed their fin towards the water. Interestingly, “They roll back onto their lateral aspect and use a tail-flip behavior to leap into a caudally-directed, ballistic flight path” (Bressman et al., 2016).

After several experiments, they found that under natural lights these fishes moved closer near the sea table that had higher frequency compared to the other sides. On the other hand, when it was dar, they didn’t have any preference (Bressman et al., 2016).

Overall, this displays that mummichogs use visual causes to find their way towards the water. This is a very interesting and unique characteristic of these species.

In the next blog, we will learn more about other unique fish species. Be sure to subscribe and leave a comment about what you would like to see!

Thanks for reading!

-Anisah Alladeen

Bressman NR, Farina S, Gibb A. 2016. Look before you leap: Visual navigation and terrestrial locomotion of the intertidal killi fish Fundulus heteroclitus . J. Exp. Zool.